Provisional text

OPINION OF ADVOCATE GENERAL

RANTOS

delivered on 16 July 2026 (1)

Case C‑467/24

2Valorise Ham NV,

2Valorise Amel NV,

2Valorise NV,

Luminus NV,

EDF Belgium NV,

ActiVent Wallonie NV,

e-NosVents NV,

CVLumiwind,

Luminus Wind Together cv,

Rouge Lux BVBA,

Biospace CV,

Federatie van de Belgische Elektriciteits- en Gasbedrijven,

Organisatie voor Duurzame Energie Vlaanderen VZW,

Wind4wallonia 2 NV,

Electrabel NV,

Eoly Energy NV

v

Ministerraad

(Request for a preliminary ruling from the Grondwettelijk Hof (Constitutional Court, Belgium))

( Reference for a preliminary ruling – Internal market for electricity – Regulation (EU) 2022/1854 – Emergency intervention to address high energy prices – Cap on market revenues obtained by electricity producers using certain energy sources – Article 7(1)(e) – Biomass fuel (solid or gaseous biomass fuels), excluding biomethane – Interpretation – Validity in the light of Articles 20 and 21 of the Charter of Fundamental Rights of the European Union – Article 6(1), Article 7(1)(e) and Article 8(1)(b) and (2) – Application of the cap of EUR 180/MWh of electricity produced to revenues from the sale of electricity produced from biomass fuels – Option or obligation for Member States to provide for a higher price cap – Validity in the light of Articles 20 and 21 of the Charter of the principles of legal certainty and the protection of legitimate expectations and the obligation to state reasons – First sentence of Article 7(3) – Option for Member States not to apply the cap to electricity generation facilities with an installed capacity of up to 1 MW – No progressivity or possibility of providing for an exception depending on the installed capacity of the facility concerned – Validity in the light of Articles 20 and 21 of the Charter – Article 6(1) – Levy of 100% on surplus revenues – Validity in the light of Article 17 of the Charter – Article 6(1) and Article 8 – Possibility for Member States to introduce a cap lower than EUR 180/MWh – National legislation introducing a cap of EUR 130/MWh – Conditions – Interpretation – Validity in the light of Articles 16 and 17 of the Charter – Article 2(5) and Article 6(1) – Determination of ‘market revenues’ – National legislation providing for the use of irrebuttable or partly rebuttable presumptions – Differentiation between producers of electricity from nuclear energy and producers of electricity from other sources – Interpretation – Validity in the light of Articles 17, 20 and 21 of the Charter – Article 6(1), Articles 7 and 8 and Article 22(2)(c) – Cap on revenues applied on a date earlier than that laid down by Regulation 2022/1854 – Interpretation – Validity in the light of the principles of legal certainty, the protection of legitimate expectations, non-retroactivity and energy solidarity and Article 17 of the Charter – Maintenance of the effects of national legislation held to be incompatible with EU law – Conditions )

I.      Introduction

1.        The present request for a preliminary ruling from the Grondwettelijk Hof (Constitutional Court, Belgium) essentially concerns the interpretation and the validity of certain provisions of Regulation (EU) 2022/1854 (2) in the light of, as the case may be, Articles 16, 17, 20 and 21 of the Charter of Fundamental Rights of the European Union (‘the Charter’), the principles of energy solidarity, legal certainty, the protection of legitimate expectations and the non-retroactivity of EU measures and the obligation to state reasons as provided for in Article 296 TFEU.

2.        The request has been made in the content of six joined sets of proceedings brought before the referring court by several undertakings which are active in the energy sector in Belgium (‘the applicants in the main proceedings’) (3) against the Ministerraad (Council of Ministers, Belgium) for annulment, in whole or in part, of national legislation setting a cap on the market revenues of certain electricity producers.

3.        In accordance with the Court’s request, this Opinion will focus on the examination of the first to eighth, tenth, twelfth, fourteenth and fifteenth questions referred for a preliminary ruling. They essentially raise novel issues concerning the interpretation and validity of several provisions of Regulation 2022/1854, which introduced, for the period from 1 December 2022 to 30 June 2023, an exceptional mechanism applying a cap on the market revenues of certain electricity producers, which was intended to capture and redistribute surplus revenues in order to mitigate the consequences of the exceptionally high energy prices resulting, in particular, from the war in Ukraine. Specifically, the referring court seeks guidance on the operation of that mechanism, including its scope and the detailed rules for its implementation by Member States, and its compatibility with certain provisions of the Charter and a number of general principles of EU law. It also raises the question of the temporal maintenance of the effects of the national legislation implementing that mechanism if it were held to be incompatible with EU law.

4.        This reference for a preliminary ruling, which follows on from a number of recent cases brought before the Court, (4) offers it an opportunity to clarify further its case-law concerning the interpretation of Regulation 2022/1854, but also to rule for the first time on the validity of several provisions of that regulation, which was designed as an exceptional, temporary instrument in the context of an unprecedented energy crisis.

II.    Legal framework

A.      European Union law

5.        According to recitals 6, 11, 23 to 25, 27 to 30, 32 to 34, 37, 40 to 42 and 46 of Regulation 2022/1854:

‘(6)      A rapid and coordinated response is therefore needed at Union level. The establishment of an emergency intervention would allow for a temporary mitigation of the risk that electricity prices and the cost of electricity for final customers reach even less sustainable levels and that Member States adopt uncoordinated national measures, which could endanger security of supply at Union level …

…

(11)      Uncoordinated caps on market revenues from electricity produced from generators with lower marginal costs such as renewables, nuclear and lignite (“inframarginal generators”) may lead to significant distortions between generators in the Union, as generators compete Union-wide on a coupled electricity market. A commitment to a joint Union-wide cap on market revenues from inframarginal generators should enable avoidance of such distortions. …

…

(23)      In the day-ahead wholesale market, the least expensive power plants are dispatched first but the price received by all market participants is set by the last plant needed to cover the demand, which is the plant with the highest marginal costs, when the market clears. …

(24)      Given the role of the price in the day-ahead market as a reference for the price in other wholesale electricity markets, and the fact that all market participants receive the clearing price, the technologies with significantly lower marginal costs have consistently recorded high revenues since the Russian military aggression against Ukraine in February 2022, well above their expectations when deciding to invest.

(25)      In a situation where consumers are exposed to extremely high prices which also harm the Union’s economy, it is necessary to limit, on a temporary basis, the extraordinary market revenues of producers with lower marginal costs by way of application of the cap on market revenues achieved through the sale of electricity within the Union.

…

(27)      The level at which the cap on market revenues is set should not jeopardise the ability of the producers to which it is applied, including renewable energy producers, to recover their investment and operating costs and should preserve and incentivise future investments in the capacity needed for a decarbonised and reliable electricity system. The cap on market revenues, being a uniform cap across the Union, is best suited to preserve the functioning of the internal electricity market …

(28)      While occasional and short-term peaks on prices can be considered a normal feature in an electricity market and may be useful for some investors to recover their generation investment, the extreme and lasting price increase observed since February 2022 is markedly different from a normal market situation of occasional peak prices. Therefore, the cap on market revenues should not be set below the reasonable expectations of market participants as to the average level of electricity prices in the hours during which the demand for electricity was at its highest, before Russia’s war of aggression against Ukraine. Before February 2022, the average peak prices in the electricity wholesale market were significantly and consistently expected below [EUR 180] per MWh across the Union in the last decades, despite the differences in electricity prices between regions in the Union. Since the initial investment decision of market participants was taken based on an expectation that, on average, the prices would be lower than that level during peak hours, setting the cap on market revenues at [EUR 180] per MWh constitutes a level well above those initial market expectations. By leaving a margin on the price that investors could reasonably have expected, it is necessary to ensure that the cap on market revenues does not counteract the initial assessment of investment profitability.

(29)      Moreover, the cap on market revenues of [EUR 180] per MWh is consistently higher, including a reasonable margin, than the current levelised cost of energy (LCOE) for the relevant generation technologies, allowing producers to which it applies to cover their investments and operating costs. Considering that the cap on market revenues leaves a considerable margin between the reasonable LCOE and the cap on market revenues, it can therefore not be expected to impair the investment in new inframarginal capacities.

(30)      The cap on market revenues should be set on market revenues … Regardless of the contractual form in which the trade of electricity may take place, the cap on market revenues should apply to realised market revenues only. …

…

(32)      The cap on market revenues should apply to technologies with marginal costs lower than the cap on market revenues, such as for instance wind, solar, nuclear energy or lignite.

(33)      The cap on market revenues should not apply to technologies with high marginal costs relating to the price of the input fuel necessary to produce electricity, such as gas and hard coal-fired power plants, as their operating costs would be significantly above the level of the cap on market revenues and its application would jeopardise their economic viability. To maintain the incentives to an overall decrease of the consumption of gas, neither should the cap on market revenues apply to technologies which directly compete with gas-fired power plants to offer flexibility to the electricity system …

(34)      The cap on market revenues should not apply to technologies using as input fuels that are substitutes for natural gas, such as biomethane, so as not to jeopardise the conversion of existing gas-fired power plants in line with the REPowerEU objectives … [(5)]

…

(37)      In order to ensure an effective enforcement of the cap on market revenues, the producers, intermediaries and relevant market participants should provide the necessary data to the competent authorities of Member States and, where appropriate, to the system operators and nominated electricity market operators. In view of the large number of individual transactions for which competent authorities of Member States have to ensure the enforcement of the cap on market revenues, those authorities should have the possibility to use reasonable estimates for the calculation of the cap on market revenues.

…

(40)      Given that the generation mix and the cost-structure of power-generating facilities differ greatly among Member States, they should be allowed to maintain or introduce national crisis measures under specific conditions.

(41)      … Member States should retain the possibility to further limit the revenues of the producers to which the cap on market revenues applies …

(42)      To ensure the security of supply, Member States should be able to set a higher cap on market revenues for producers that would otherwise be subject to the Union-wide cap on market revenues, when their investment and operating costs are higher than the Union-wide cap on market revenues.

…

(46)      Member States should ensure that the surplus revenues resulting from the application of the cap on market revenues in the field of electricity are passed on to final electricity customers to mitigate the impact of exceptionally high electricity prices …’

6.        Article 2 of that regulation, entitled ‘Definitions’, stated, in paragraph 5:

‘For the purposes of this Regulation, … the following definitions also apply:

…

(5)      “market revenue” means realised income a producer receives in exchange for the sale and delivery of electricity in the Union, regardless of the contractual form in which such exchange takes place …’

7.        Article 6 of the regulation, entitled ‘Mandatory cap on market revenues’, stipulated, in paragraphs 1 to 3:

‘1.      Market revenues of producers obtained from the generation of electricity from the sources referred to in Article 7(1) shall be capped to a maximum of [EUR 180] per MWh of electricity produced.

2.      Member States shall ensure that the cap on market revenues targets all the market revenues of producers …

3.      Member States shall put effective measures in place to prevent a circumvention of the obligations on producers pursuant to paragraph 2 …’

8.        Article 7 of that regulation, entitled ‘Application of the cap on market revenues to electricity producers’, provided, in paragraphs 1, 3 and 5:

‘1.      The cap on market revenues provided for in Article 6 shall apply to the market revenues obtained from the sale of electricity produced from the following sources:

(a)      wind energy;

(b)      solar energy (solar thermal and solar photovoltaic);

(c)      geothermal energy;

(d)      hydropower without reservoir;

(e)      biomass fuel (solid or gaseous biomass fuels), excluding biomethane;

(f)      waste;

(g)      nuclear energy;

(h)      lignite;

(i)      crude petroleum products;

(j)      peat.

…

3.      Member States may, in particular in cases where the application of the cap on market revenues provided for in Article 6(1) leads to a significant administrative burden, decide that the cap on market revenues does not apply to producers generating electricity with power-generating facilities with an installed capacity of up to 1 MW …

…

5.      Member States may decide that the cap on market revenues only applies to 90% of the market revenues exceeding the cap on market revenues provided for in Article 6(1).’

9.        Article 8 of Regulation 2022/1854, entitled ‘National crisis measures’, provided:

‘1.      Member States may:

(a)      maintain or introduce measures that further limit the market revenues of producers generating electricity from the sources listed in Article 7(1), including the possibility to differentiate between technologies …

(b)      set a higher cap on market revenues for producers generating electricity from the sources listed in Article 7(1), provided that their investments and operating costs exceed the maximum set in Article 6(1);

…

2.      The measures referred to in paragraph 1 shall, in line with this Regulation:

(a)      be proportionate and non-discriminatory;

(b)      not jeopardise investment signals;

(c)      ensure that the investments and operating costs are covered;

(d)      not distort the functioning of electricity wholesale markets, and in particular, not affect the merit order and the price formation on the wholesale market;

(e)      be compatible with Union law.’

10.      Article 22 of the regulation, entitled ‘Entry into force and application’, was worded as follows:

‘1.      This Regulation shall enter into force on the day following that of its publication in the Official Journal of the European Union.

2.      … this Regulation shall apply until 31 December 2023, subject to the following:

…

(c)      Articles 6, 7, and 8 shall apply from 1 December 2022 to 30 June 2023;

…’

B.      Belgian law

11.      Article 2 of the loi relative à l’organisation du marché de l’électricité (Law on the organisation of the electricity market) of 29 April 1999, (6) as amended by the Law amending that Law and introducing a cap on the revenues of electricity producers of 16 December 2022, (7) applicable to the main proceedings (‘the Law of 16 December 2022’), stated that it ensured ‘the partial implementation of [Regulation 2022/1854]’.

12.      Article 22b of that Law was worded as follows:

‘§ 1.      This Article establishes a cap on revenues from the electricity producers’ market, through a levy payable to the State on surplus revenues generated between 1 August 2022 and 30 June 2023 by the debtors referred to in paragraph 2.

§ 2.      The levy is payable by:

1°      any natural or legal person who, during the period referred to in paragraph 1, has fed electricity into the transmission network, a network with a transmission function, a (closed) distribution network, a closed industrial network, a railway traction network or a direct line, by means of an electricity generation facility located in Belgium using one of the technologies listed in Article 7[(1)] of Regulation [2022/1854], with a minimum installed capacity of 1 MW;

2°      any nuclear operator …;

3°      any contributory company …;

4°      any owner of a nuclear power plant referred to in Article 4/1 of the loi du 31 janvier 2003 sur la sortie progressive de l’énergie nucléaire à des fins de production industrielle d’électricité (Law of 31 January 2003 on the phasing out of nuclear energy for industrial electricity production). [(8)]

…

§ 3.      The levy payable by the debtor referred to in paragraph 2 shall be equal to 100% of the surplus revenues.

Surplus revenues represent the positive difference between market revenue and the cap on market revenue as set in accordance with paragraph 4, calculated for each electricity sales transaction in MWh delivered during the period referred to in paragraph 1, and per electricity generation facility located in Belgium using one of the technologies listed in Article 7[(1)] of Regulation [2022/1854], with a minimum installed capacity of 1 MW.

…

§ 4.      The cap on revenue from the market is EUR 130 per MWh of electricity.

…

By way of derogation from subparagraph 1, the cap on market revenue shall be EUR 180/MWh of electricity for facilities which produce electricity from solid or gaseous biomass fuels.

…’

13.      Under the first subparagraph of paragraph 5 of Article 22b of that Law, ‘market revenues’ were defined as the income obtained for each transaction by the electricity producers concerned in exchange for the sale and delivery of electricity during the period referred to in paragraph 1 of that article. (9)

14.      The second subparagraph of paragraph 5 introduced a series of presumptions for the purpose of determining market revenues, which varied according to the categories of production facilities concerned. Points 1 and 2 of that subparagraph provided for irrebuttable presumptions applying to nuclear power stations. Points 3 to 5 established rebuttable presumptions applying to: facilities not referred to in points 1 and 2 whose production was covered by a power purchase agreement (point 3); facilities not covered by points 1, 2 and 3 which did not benefit from a production support mechanism or which benefitted from such a mechanism, the amount of which did not depend on changes in the price of electricity or the amount of which depended on changes in the price of electricity only over a three-year period (point 4); and all other facilities not covered by points 1, 2, 3 and 4 (point 5). Under point 6 of that subparagraph, producers covered by the rebuttable presumptions set out in points 3 to 5 could rebut those presumptions by proving that the market revenues actually generated differed from those determined pursuant to those presumptions, provided that they adduced that proof for all their production facilities. Those presumptions could be rebutted, however, only through the following presumptions:

‘(a)      sales and purchases of electricity within a vertically integrated undertaking or between undertakings, one of which is controlled or partially owned, directly or indirectly, by the other, shall be deemed to have been concluded for the purposes of this article on the basis of a price consistent with the market price on the day of the transaction for the delivery period covered by the transaction, as published by an energy block exchange platform operating in Belgium;

(b)      any volume of electricity produced and sold, but not sold forward, is deemed to have been sold at the market reference price;

(c)      each forward electricity sale constitutes a transaction defined by its transaction date, price and volume;

(d)      the volume of electricity sold on the day-ahead market is considered to have been traded for each one-hour delivery period.’

III. The dispute in the main proceedings, the questions referred for a preliminary ruling and the procedure before the Court

15.      By applications received at the registry of the Grondwettelijk Hof (Constitutional Court), the referring court, on 21 and 22 June 2023, the applicants in the main proceedings each brought an action before that court for annulment, in whole or in part, of the Law of 16 December 2022. The six cases brought before that court have been joined.

16.      In support of their action, 2Valorise and Others submit, in essence, that Article 5 of the Law of 16 December 2022 infringes Article 8 of Regulation 2022/1854 in that it applies a cap of EUR 180/MWh both to undertakings producing electricity from biomass waste and to those producing electricity from other fuels, even though the former bear higher investment and operating costs. In their view, Article 8 of that regulation prohibits Member States from introducing a cap which prevents electricity producers from recovering their costs. By setting such a cap, Article 5 of that Law thus breaches that prohibition.

17.      Luminus and Others submit, first, that Article 5 of the Law of 16 December 2022 infringes, in particular, Article 2(5) and (9) and Articles 6 to 8 of Regulation 2022/1854 and Article 17 of the Charter, in that it establishes presumptions to determine the market revenue to which the cap at issue in the main proceedings is applied; those presumptions are either irrebuttable or rebuttable through other presumptions, which are themselves also irrebuttable, when the provisions of that regulation referred to above require the cap to be applied to income which a producer obtains from a transaction, that is to say, from revenue actually obtained. Second, they claim that that Article 5 infringes Articles 6 and 8 of the regulation and Articles 16 and 17 of the Charter, in that it introduces a cap of EUR 130/MWh, even though Article 6 of the regulation lays down a cap of EUR 180/MWh and the conditions set out in Article 8 thereof for being able to adopt measures that further limit market revenue are not satisfied.

18.      Rouge Lux and Biospace argue, first, that the Law of 16 December 2022 is incompatible with Article 7(1)(e) of Regulation 2022/1854, in so far as it applies a levy to producers producing electricity from biogas through a biomethanisation process and using a cogeneration plant, but not to those producing electricity from biomethane through purification and compression of biogas and through a biomethanisation process, even though those two categories use comparable production techniques. That difference in treatment is not therefore based on an objective criterion and is not reasonably justified. Second, they criticise Article 7(3) of Regulation 2022/1854 in so far as it simply permits Member States to exempt from the levy producers generating electricity with electricity generation facilities with an installed capacity of up to 1 MW, without, however, providing for the possibility of a progressive levy or exceptions for certain types of facility.

19.      FEBEG and Others submit, first, that Article 5 of the Law of 16 December 2022 infringes Articles 6 to 8, 20 and 22 of Regulation 2022/1854, Article 288 TFEU and the principles of sincere cooperation, primacy, effectiveness, energy solidarity, legal certainty and non-retroactivity, in that it applies the levy from 1 August 2022. However, in their view, that regulation authorises Member States to cap market revenues only from 1 December 2022 and the objective of general interest pursued by the regulation cannot justify the retroactivity of that Law. Second, like Luminus and Others, they criticise the application of the levy to revenue determined on the basis of presumptions. Lastly, again like Luminus and Others, they challenge the setting of the cap at EUR 130/MWh of electricity produced.

20.      Electrabel criticises, first, like Luminus and Others and FEBEG and Others, the application of the levy at issue in the main proceedings to revenue determined on the basis of presumptions. Second, in the same way as FEBEG and Others, it claims that the application of a cap on revenues from 1 August 2022 infringes Article 22(2)(c) of Regulation 2022/1854 and the principles of proportionality and subsidiarity. Third, it maintains that the cap of EUR 130/MWh infringes Article 2(9) and Articles 6 to 8 of that regulation, since it is clear from Article 8(1)(d) thereof, in particular, that it is possible to set a specific cap only on the market revenue obtained from the sale of electricity produced from hard coal. Fourth, Electrabel claims that the Law of 16 December 2022 gives rise to disproportionate interference with the right to property enshrined in Article 17 of the Charter in so far as it provides for a tax rate of 100% applied to a tax base determined through presumptions, a reduction in the cap to EUR 130/MWh and the application of the cap prior to the entry into force of the regulation.

21.      For its part, Eoly claims that the Law of 16 December 2022 infringes Article 2(5) and Articles 6 and 7 of Regulation 2022/1854, Article 288 TFEU and the principles of primacy and effectiveness. In its view, Article 5 of that Law creates a difference in treatment between, on the one hand, taxpayers subject to the levy, which are taxed on the basis of non-existent income that is presumed irrebuttably, and, on the other, those subject to other taxes, which are not taxed on the basis of such income. In addition, Eoly submits that since it is contractually protected against fluctuations in the wholesale price of electricity, it did not derive any benefit from the price spikes which justified the introduction of the cap at issue. Therefore, that cap cannot be applied to it.

22.      The Council of Ministers challenges those six actions in their entirety. Furthermore, it requests the referring court, should the Law of 16 December 2022 be annulled, to maintain its effects for the past in the light of the significant budgetary and administrative difficulties which would result from unmodulated annulment. Such annulment, which would not maintain the effects of that law, would be likely to give rise to an infringement of Regulation 2022/1854 since the obligation which it imposes on Member States to introduce the cap laid down therein would then no longer be complied with. That position is opposed by the applicants in the main proceedings, which argue, in particular, that budgetary or administrative reasons cannot be sufficient to justify maintaining the effects of national legislation which is contrary to EU law.

23.      In those circumstances, the referring court seeks guidance, in the first place, regarding the non-application of the levy at issue in the main proceedings to facilities which produce electricity from biomethane, while producers of electricity from biogas through a biomethanisation process and using a cogeneration plant, such as Rouge Lux and Biospace, are subject to the levy.

24.      In that regard, that court notes, first, that Article 7(1)(e) of Regulation 2022/1854 refers to electricity ‘produced’ from ‘biomass fuel (solid or gaseous biomass fuels), excluding biomethane’ and that, according to recital 34 of that regulation, the cap on market revenue should not apply to technologies using input fuels that are substitutes for natural gas, such as biomethane. However, the regulation does not give a precise description of ‘biomass fuels’, other than that they are solid or gaseous fuels. Furthermore, point 28 of the second subparagraph of Article 2 of Directive (EU) 2018/2001 (10) defines ‘biogas’ as ‘gaseous fuels produced from biomass’. Thus, since recital 34 does not refer to electricity ‘produced’ from biomethane, but to the ‘use’ of biomethane and power plants that ‘use’ biomethane, it remains uncertain whether Rouge Lux and Biospace, which produce electricity from biogas through a biomethanisation process and using a cogeneration plant, fall within the scope of the cap.

25.      Second, the question arises whether Article 7(1)(e) of Regulation 2022/1854 is compatible with Articles 20 and 21 of the Charter in that it excludes from the scope of the levy market revenue from the sale of electricity produced from biomethane through purification and compression of biogas and through a biomethanisation process, while it does not exclude market revenue from the sale of electricity produced from biogas through a biomethanisation process and using a cogeneration plant. The referring court notes in that respect that in the REPowerEU plan biogas and biomethane are presented as being comparable energy sources in the context of the transition from fossil energy to renewable energy.

26.      In the second place, with regard to the non-application of the levy at issue in the main proceedings to facilities with an installed capacity of up to 1 MW, as provided for by the Law of 16 December 2022, that court observes that it implements the option offered in the first sentence of Article 7(3) of Regulation 2022/1854, which is justified by the Belgian legislature on the ground that, below that threshold, the producers concerned must be considered small producers for which the administrative burden connected with the collection of the levy would be disproportionate, given the quantity of electricity which could be sold to third parties. Nevertheless, the threshold particularly affects producers of electricity from biomass, since many biomass power plants have an installed capacity slightly higher or slightly lower than 1 MW. It is true that, in view of the objectives pursued by the regulation, there is reasonable justification to set a threshold at 1 MW. However, in so far as exceeding that threshold gives rise to the application of a levy at a rate of 100% of the revenues above the cap, the question arises whether the first sentence of Article 7(3) of the regulation, in so far as it establishes such a threshold without giving Member States the possibility to introduce a progressive rate or to establish a derogation or exception depending on the installed capacity of the facility concerned, is compatible with Articles 20 and 21 of the Charter.

27.      In the third place, with regard to the rate of the levy at issue in the main proceedings, the referring court considers that, also taking into account the option to adopt a cap lower than EUR 180/MWh, a rate set at 100% could constitute interference with the right to enjoyment of property which could disturb the fair balance between the requirements of general interest and those relating to the protection of the right to property. Because the levy rate of 100% provided for by the Law of 16 December 2022 was adopted from Article 6(1) of Regulation 2022/1854, the question arises whether that provision, in that it entails a levy of 100% of revenues exceeding the cap set, is consistent with Article 17 of the Charter.

28.      In the fourth place, the referring court asks about the reduction of the general cap to EUR 130/MWh adopted by the Belgian legislature. First, questions arise regarding the relationship between Article 6(1) of Regulation 2022/1854 and Article 8(1)(a) and (b) thereof, in particular as regards the meaning of the word ‘maximum’ in Article 6(1).

29.      Second, doubt remains whether Article 6(1) of that regulation permits a Member State to set a cap which is EUR 50/MWh lower than the cap established by the regulation, given the significance of such a reduction. That court notes in that regard the need to safeguard the interests of electricity producers, which is one of the objectives pursued by that regulation, while taking account of its broad logic, which is to provide a coordinated response to the increase in energy prices.

30.      Third, the referring court asks whether the cap introduced by Article 5 of the Law of 16 December 2022 can be justified on the basis of Article 8(1)(a) and (2) of Regulation 2022/1854. More precisely, it must be determined whether a reduction of that cap is to be regarded as a ‘national crisis measure’ within the meaning of the title of Article 8 of that regulation, when the Belgian legislature relied on paragraph 1(a) thereof only in respect of the general rationale for the introduction of the cap, namely the increase in prices on the Belgian electricity market. Consequently, there are doubts whether Article 6(1) and Article 8 of the regulation permit a Member State to set the cap on market revenues at EUR 130/MWh.

31.      Fourth, the referring court asks about the introduction of the cap of EUR 130/MWh by Article 5 of the Law of 16 December 2022, and in particular whether it gives rises to disproportionate interference with the right to property and the freedom to conduct a business guaranteed by the Charter and whether it is compatible with Article 194(1) TFEU, the provision from which the Court derived the ‘principle of energy solidarity’, which is established as a ‘fundamental principle of EU law’. (11)

32.      In the fifth place, with regard to the cap of EUR 180/MWh laid down for facilities which produce electricity from solid or gaseous biomass fuels, the referring court notes that Article 8(1)(b) of Regulation 2022/1854 permits Member States to set a higher cap on market revenues for producers generating electricity from the sources listed in Article 7(1) thereof, provided that investments and operating costs exceed the maximum set in Article 6(1) of that regulation in order, according to recital 42, to ensure security of supply. However, the competent Belgian authorities had stated, during the parliamentary debates leading to the adoption of the Law of 16 December 2022, that if those facilities faced higher production costs, the general level of EUR 180/MWh could be maintained, failing any objective data showing that investments and operating costs exceeded the maximum, as required by Article 8(1)(b) of the regulation.

33.      In view of those factors, as well as of the objective data which 2Valorise and Others claim to have submitted to substantiate the higher costs faced by them, but also given that Article 6(1) of that regulation allows Member States alone to introduce a cap of a ‘maximum’ of EUR 180/MWh, from which a derogation may be made only under the conditions set out in Article 8 thereof, the question arises of the validity of Article 6(1) and Article 7(1)(e) of Regulation 2022/1854 in so far as they also impose the obligation to cap market revenues at EUR 180/MWh for electricity produced from biomass fuels. If the Court were to confirm the validity of those provisions, it would also have to be determined whether Article 8(1)(b) and (2) of that regulation requires Member States to introduce a cap higher than EUR 180/MWh for facilities producing electricity from solid or gaseous biomass fuels.

34.      In the sixth place, as regards the presumptions established to calculate the market revenues to which the levy is applied, the referring court states that, of the five presumptions provided for by the Law of 16 December 2022, the first two, which are irrebuttable, relate to nuclear power plants, refer to methods for calculating revenues established by the laws governing such power plants and are consistent with the sales strategies defined by those laws. According to the preparatory works referred to above, the fact that those presumptions are based on calculation methods laid down in the laws concerned justifies the fact that they cannot be rebutted. Conversely, the third, fourth and fifth presumptions can be rebutted. The operator concerned must adduce proof for all its production facilities that the market revenues differ from those determined pursuant to one of those presumptions. The possibility of rebutting those presumptions is, however, framed by a set of binding assumptions for the operator, which, according to those preparatory works, constitute real ‘safeguards’.

35.      Nevertheless, although Regulation 2022/1854 does not specify how those revenues are to be established, Article 6(1) thereof suggests that the regulation is referring to the revenues actually realised. That being so, recital 37 of the regulation allows the use of reasonable estimates and the Belgian legislature considered that it was not possible to determine precisely a price for each MWh sold and supplied in the course of the relevant period. The use of presumptions is also based on Article 6(3) of that regulation, which requires Member States to adopt effective measures to prevent the application of the cap on market revenues obtained by electricity producers being circumvented.

36.      The referring court also notes that the calculations presented by Luminus and Others, FEBEG and Others, Electrabel and Eoly to demonstrate the existence of significant differences between their real revenues and the results of the contested estimates seem to be credible. There is therefore doubt as to the interpretation of Article 2(5) and Article 6(1) of Regulation 2022/1854, read in the light of recital 30 thereof, in so far as they could allow a Member State to rely on presumptions, rather than on the revenues actually realised from the sale and delivery of electricity, in determining the market revenues subject to the cap. That doubt relates in particular to the scope of the presumptions, in that the operator subject to the cap either cannot rebut them or it can do so only on the basis of another presumption, which does not take account of the revenues actually obtained. The fact that the use of presumptions is intended to reduce the administrative burden on operators subject to the cap and to prevent the circumvention of the levy is not sufficient to remove that doubt, in particular since a presumption of fraud and abuse cannot justify a tax measure of general application which determines a flat-rate tax base, without allowing the operator the possibility to demonstrate that those circumstances are not present.

37.      In the event that that question is answered in the affirmative, it must be determined whether Article 2(5) and Article 6(1) of that regulation, read in the light of recital 30 thereof, permit a Member State, in using presumptions, to differentiate between producers of electricity from nuclear energy, which cannot rebut the presumptions applicable to them, and other producers of electricity from other sources, who can, on the basis of another presumption, rebut the presumptions applicable to them. In addition, the referring court asks, first, whether, if those provisions allow a Member State to determine, on the basis of presumptions alone, the market revenues to which the cap is applied, without the possibility for the producers concerned to demonstrate their actual revenues, those provisions are compatible with the right to property enshrined in Article 17 of the Charter. Second, if those provisions permit a Member State, in using presumptions to determine market revenues, to differentiate between producers of electricity from nuclear energy and those producing electricity from other energy sources, that court asks whether the abovementioned provisions are compatible with Articles 20 and 21 of the Charter.

38.      In the seventh place, the referring court enquires about the temporal application of the levy at issue in the main proceedings. It notes that it applied to surplus revenues realised between 1 August 2022 and 30 June 2023, while Regulation 2022/1854 entered into force only on 8 October 2022 and the cap laid down therein was applicable from 1 December 2022 to 30 June 2023. That regulation does not expressly provide for the possibility for Member States to apply that cap before 1 December 2022, although that possibility was included in the initial proposal which led to its adoption. The question therefore arises of the extent to which the regulation permits a Member State to apply the cap laid down in Article 6(1) thereof before the date of application specified in that regulation and, in that case, whether such application is compatible with the principles of legal certainty, the protection of legitimate expectations, non-retroactivity of laws and energy solidarity, and with Article 17 of the Charter.

39.      In the eighth place and lastly, with regard to the request made in the alternative by the Council of Ministers regarding the definitive maintenance of the effects of the provisions of the national legislation at issue in the main proceedings, were those provisions to be annulled, the referring court notes two circumstances raised by the Council of Ministers. First, the Council of Ministers highlighted the budgetary and administrative problems that would result from unmodulated annulment, since the revenue from the levies has already been used to finance various measures to limit the effects of high electricity prices for final customers. Second, it argues that the Law of 16 December 2022 partially implemented Regulation 2022/1854, which requires the federal authority to cap market revenues received by electricity producers between 1 December 2022 and 30 June 2023. The effect of a retroactive annulment of that Law would thus be that no cap would apply in Belgium. The court notes in that regard that account must be taken of the limitations arising from EU law connected with the maintenance of the effects of national rules that should be annulled because they are contrary to that law. Those effects could therefore be maintained only under the conditions laid down by the Court in answer to a question referred for a preliminary ruling on that point.

40.      In those circumstances, the Grondwettelijk Hof (Constitutional Court) decided to stay the proceedings and to refer 15 questions to the Court for a preliminary ruling, of which the following are the subject of this targeted Opinion:

‘(1)      Should Article 7(1)(e) of [Regulation 2022/1854] be interpreted as meaning that only electricity produced from biomethane through purification and compression of biogas and through a biomethanisation process and not electricity produced from biogas through a biomethanisation process and using a cogeneration plant is excluded from the scope of the cap on market revenues from the sale of electricity laid down in Article 6 of that regulation?

(2)      If the first question must be answered in the affirmative, does Article 7(1)(e) of [Regulation 2022/1854], in the interpretation according to which only electricity produced from biomethane through purification and compression of biogas and through a biomethanisation process and not electricity produced from biogas through a biomethanisation process and using a cogeneration plant is excluded from the scope of the cap on market revenues from the sale of electricity laid down in Article 6 of that regulation, infringe Articles 20 and 21 of the [Charter]?

(3)      Does Article 7(3), first sentence, of [Regulation 2022/1854] infringe Articles 20 and 21 of the [Charter] in that it allows Member States, in particular in cases where the application of the cap on market revenues laid down in Article 6(1) of that regulation entails significant administrative burdens, to declare the cap inapplicable to producers generating electricity with production facilities with an installed capacity of up to 1 MW, without allowing Member States to provide for a progressive tariff or for a derogation or exception depending on the installed capacity of the facility concerned?

(4)      Does Article 6(1) of [Regulation 2022/1854], whether or not taking into account the answers to be given to the fifth and sixth questions, infringe Article 17 of the [Charter], in that, by providing that the market revenues of the electricity producers listed in Article 7(1) of that regulation are “capped” at a maximum of EUR 180/MWh, it implies that the surplus of such revenues is subject to a levy rate of 100 per cent?

(5)      Should Article 6(1) and Article 8 of [Regulation 2022/1854], read in the light of recital 40 thereof, be interpreted as allowing Member States to introduce a national measure whereby, like Article 5 of the [Law of 16 December 2022], the cap on market revenues is set at EUR 130/MWh, with reference by way of justification to the increase in prices on the Belgian electricity market?

(6)      If the fifth question must be answered in the affirmative, do Articles 6(1) and 8 of [Regulation 2022/1854] infringe Articles 16 and 17 of the [Charter] and the principle of energy solidarity under EU law?

(7)      Do Article 6(1) and Article 7(1)(e) of [Regulation 2022/1854] infringe Articles 20 and 21 of the [Charter], the principles of legal certainty and the protection of legitimate expectations, as well as the duty to state reasons as provided for in Article 296 [TFEU], in that they also apply the compulsory cap on market revenues of a maximum of EUR 180/MWh to the sale of electricity produced from biomass fuels (solid or gaseous biomass fuels)?

(8)      Should Article 8(1)(b) and (2) of [Regulation 2022/1854] be interpreted as requiring Member States to introduce a higher price cap for facilities producing electricity from solid or gaseous biomass fuels than the EUR 180/MWh price cap provided for in Article 6(1) of that regulation?

…

(10)      Should Article 2(5) and Article 6(1) of [Regulation 2022/1854], read in the light of recital 30 thereof, be interpreted as permitting a Member State to differentiate, with regard to the use of presumptions for determining the market revenues to which the price cap is applied, between producers of electricity from nuclear energy and producers of electricity from other sources?

…

(12)      If the tenth question must be answered in the affirmative, do Article 2(5) and Article 6(1) of [Regulation 2022/1854], read in the light of recital 30 thereof, infringe Articles 20 and 21 of the [Charter]?

…

(14)      If the thirteenth question [(12)] must be answered in the affirmative, do [Article 6(1), Articles 7 and 8 and Article] 22(2)(c) of Regulation 2022/1854] infringe the principles of legal certainty and the protection of legitimate expectations and the principle of non-retroactivity of legal rules, the principle of energy solidarity and Article 17 of the [Charter]?

(15)      Should EU law be interpreted as meaning that, if the [Grondwettelijk Hof (Constitutional Court)] were to conclude, on the basis of the answers to the aforementioned questions, that the … Law of 16 December 2022, which implements [Regulation 2022/1854], infringes one or more of the obligations arising from the provisions referred to in those questions, EU law would prevent the [Grondwettelijk Hof (Constitutional Court)] from upholding the effects of the … Law of 16 December 2022?’

41.      Written observations were submitted to the Court by 2Valorise and Others, Luminus and Others, Rouge Lux and Biospace, FEBEG and Others, Electrabel, Eoly, the Belgian and Austrian Governments, the Council of the European Union and the European Commission.

IV.    Analysis

42.      Before embarking on the analysis of the questions referred for a preliminary ruling by the national court on which the targeted Opinion has been requested by the Court, it would seem useful to explain briefly the main issues raised by those questions, which can be grouped as follows:

–        a question concerning interpretation and a question concerning validity relating to the scope of Article 7(1) of Regulation 2022/1854 and the application of the cap to revenues from the sale of electricity produced from biomass fuels (first and second questions);

–        a question concerning validity relating to the threshold of installed capacity of up to 1 MW, which delimits a category of producers to which Member States may opt not to apply the cap on revenues laid down by that regulation (third question);

–        a question concerning validity relating to the levy rate for revenues exceeding the cap, which is set, in principle, at 100% under the regulation (fourth question);

–        a question concerning interpretation and a question concerning validity relating to the cap of EUR 130/MWh set by the Law of 16 December 2022, when Article 6(1) of that regulation establishes, in principle, a cap of EUR 180/MWh (fifth and sixth questions);

–        a question concerning interpretation and a question concerning validity in relation to the application of the cap to revenues from the sale of electricity produced from biomass fuels (seventh and eighth questions);

–        two questions concerning interpretation and two questions concerning validity relating to the possibility of using presumptions to determine the amount of market revenues to which the cap is applied, as provided for in that Law (ninth to twelfth questions);

–        a question concerning interpretation and a question concerning validity regarding the temporal scope of the cap introduced by Regulation 2022/1854 and any effects thereof on the competences of the Member States (thirteenth and fourteenth questions), and

–        a question concerning the possibility for the referring court to maintain the effects of that Law if it were to find that the Law infringes one or more of the provisions of that regulation (fifteenth question).

A.      The first and second questions referred for a preliminary ruling

43.      By its first question, the referring court asks, in essence, whether Article 7(1)(e) of Regulation 2022/1854 must be interpreted as meaning that only electricity produced from biomethane obtained by purification and compression of biogas through a biomethanisation process, except for electricity produced from biogas through such a process using a cogeneration plant, is excluded from the scope of the cap on market revenues laid down in Article 6 of that regulation. (13) If so, that court is uncertain as to the validity of Article 7(1)(e) of the regulation in the light of Articles 20 and 21 of the Charter, in so far as it exempts from that cap market revenues from the sale of electricity produced from biomethane obtained by purification and compression of biogas from a biomethanisation process, while excluding from that exemption revenues from the sale of electricity produced from biogas obtained from that same process and generated using a cogeneration plant.

44.      The Court is therefore invited, in the first place, to clarify the scope of Article 7(1)(e) of Regulation 2022/1854 and, in particular, to determine whether biogas should be classified as a ‘fuel produced from biomass’  or, as the case may be, ‘biomethane’,  such classification being crucial in establishing whether or not the revenues of the producers concerned are subject to the cap mechanism laid down in Article 6 of that regulation.

45.      I note as a preliminary point that it follows from a combined reading of Article 6(1) and Article 7(1)(e) of Regulation 2022/1854 that market revenues of producers obtained from the generation of electricity from solid or gaseous biomass fuels are subject to the cap laid down in that regulation, whereas market revenues from the sale of electricity from biomethane are excluded from it. It should be stated, however, that, although the EU legislature intended to accord distinct treatment to those two energy sources, neither ‘biomass fuels’ nor ‘biomethane’ is defined by Regulation 2022/1854. (14) The same is true of ‘biogas’, to which the national court refers and which is not expressly mentioned in Article 7(1)(e) of the regulation.

46.      In order to answer the first question referred, those terms must be interpreted by reference to their usual meaning in everyday language, considering the context in which they occur and the objectives pursued by Regulation 2022/1854. (15)

47.      I note that, in Article 2(27) and (28) respectively, Directive 2018/2001 defines ‘biomass fuels’ (16) as ‘gaseous and solid fuels produced from biomass’ and ‘biogas’ as ‘gaseous fuels produced from biomass’. (17)

48.      As for ‘biomethane’, which was not defined in EU law at the time when Regulation 2022/1854 was adopted, (18) it is not disputed that that term refers, from a chemical point of view, to high-purity, non-fossil methane (CH4) produced from biological sources through purification and compression of biogas. That purification and compression process removes impurities contained in biogas, resulting in a gas with a quality level comparable to natural gas. Biomethane can therefore be a substitute for natural gas in many applications, including injection into natural gas networks and electricity generation.

49.      It is apparent, prima facie, from the foregoing that biogas and biomethane are two distinct products, both in terms of their chemical composition and degree of processing and in terms of their respective uses. Biogas can be regarded in that respect as an ‘intermediate’ product, whereas biomethane appears to be a ‘more refined’ or ‘finished’ product resulting from the purification of biogas. Accordingly, biomethane has chemical characteristics comparable to the fossil natural gas injected into networks or used for electricity generation.

50.      As far as the specific objectives pursued by Regulation 2022/1854 are concerned, it is clear from the list of energy sources in Article 7(1) that the cap on market revenues applies only to extraordinary and unexpected revenues from the sale of electricity produced through technologies with marginal costs lower than that cap (‘inframarginal’ revenues). However, electricity generation technologies with high marginal costs, including those based on natural gas, do not fall within the scope of that provision, in particular because of the cost of the fuel used. (19) The EU legislature considered that the application of the cap to those technologies, which were severely affected by the energy crisis, could jeopardise both the economic viability of the producers concerned and the security of supply. I also note that recital 34 of that regulation, to which the national court refers, states that the cap on market revenues should not apply to technologies using input fuels that are substitutes for natural gas, such as biomethane, so as not to jeopardise the conversion of existing gas-fired power plants, in line with the objectives of the REPowerEU plan. (20)

51.      In the light of those factors, I consider that a differentiation should be made between the two electricity generation techniques identified by the referring court in its first question: on the one hand, ‘electricity produced from biomethane obtained as a result of purification and compression of biogas through the biomethanisation process’ and, on the other, ‘electricity produced from methane of biological origin contained in that biogas’. In the former case, biogas undergoes additional processing to extract carbon dioxide and other impurities so as to obtain a gas with characteristics equivalent to natural gas which is, as such, capable of being injected into gas networks, including as a substitute for natural gas. By contrast, in the latter case, electricity is produced directly from biogas without a prior purification operation, the methane which it contains being used in its existing state, together with other gases. (21) Therefore, although those two categories of electricity ultimately have a common biological origin in methane, they correspond to distinct technical production processes which the EU legislature intended to treat differently for the purposes of the application of the cap because of the significant difference in marginal costs between those two technologies.

52.      As regards, in the second place, the issue of the difference in treatment between biomass fuels which is the subject of the second question referred, it should be borne in mind at the outset that, according to the Court’s settled case-law, Article 20 of the Charter, under which everyone is equal before the law, enshrines the general principle of EU law of equal treatment, which requires that comparable situations must not be treated differently and different situations must not be treated in the same way unless such treatment is objectively justified. (22) As far as Article 21 of the Charter is concerned, that provision prohibits any discrimination. That being said, the prohibition on discrimination is merely a specific expression of the general principle of equality which is one of the fundamental principles of EU law and that principle, which is also reflected in Article 20 of the Charter, requires that comparable situations must not be treated differently and that different situations must not be treated in the same way unless such treatment is objectively justified. (23)

53.      According to that case-law of the Court, the comparability of different situations must be assessed with regard to all the elements which characterise them. These elements must, in particular, be determined and assessed in the light of the subject matter and purpose of the EU act which makes the distinction in question. The principles and objectives of the field to which the act relates must also be taken into account. (24) Moreover, the Court has repeatedly held, as regards judicial review of whether the EU legislature has observed the principle of equal treatment, that that legislature has, in the exercise of the powers conferred on it, a broad discretion where it intervenes in a field involving political, economic and social choices and where it is called on to undertake complex assessments and evaluations. Thus, only if a measure adopted in this field is manifestly inappropriate in relation to the objectives which the competent institutions are seeking to pursue can the lawfulness of such a measure be affected. (25)

54.      Since, as was observed in points 49 to 51 of this Opinion, biogas and biomethane are actually two distinct products, both in terms of their essential characteristics and in terms of the way they are used for electricity generation, and the EU legislature intended to differentiate, in the application of the cap, between the different technologies based on their marginal costs and their capacity to be a substitute for natural gas, (26) the differentiation made between those two technologies is based on objective criteria and appears to be reasonably justified having regard to the objectives pursued by Regulation 2022/1854. (27) It follows that the difference in treatment alleged by some of the applicants in the main proceedings cannot be established because the producers or technologies in the present case are not in comparable situations which have been treated differently within the meaning of the Court’s case-law recalled in points 52 and 53 of this Opinion.

55.      In the light of the foregoing, I am of the view that the answer to the first question must be that Article 7(1)(e) of Regulation 2022/1854 must be interpreted as meaning that only revenues from the sale of electricity produced from biomethane, except for electricity produced from biogas through such a process using a cogeneration plant, are excluded from the scope of the cap laid down in Article 6 of that regulation. Such an interpretation is not contrary to Articles 20 and 21 of the Charter.

B.      The third question referred for a preliminary ruling

56.      By its third question, which should be examined in the light of my proposed answers to the first two questions, the referring court asks, in essence, whether the first sentence of Article 7(3) of Regulation 2022/1854 is valid in the light of Articles 20 and 21 of the Charter in so far as it permits Member States to decide that the cap on market revenues laid down in Article 6(1) of that regulation does not apply to producers generating electricity with production facilities with an installed capacity of up to 1 MW, without offering them the possibility to provide for a progressive levy rate or a derogation or exception which takes account of the installed capacity of the facility concerned. (28)

57.      I note that Article 7(3) of Regulation 2022/1854 offers Member States the possibility to decide that the cap does not apply to electricity producers using facilities with an installed capacity of up to 1 MW, in particular where the application of that cap would be likely to lead to a significant administrative burden.

58.      It should be noted in that regard that the prevention of excessive administrative burdens has already been recognised by the Court as constituting an appropriate criterion for differentiation, including in contexts where there was no degree of urgency, (29) which is the case here with the energy crisis which led to the adoption of Regulation 2022/1854.

59.      There is no doubt, in my view, that the threshold of 1 MW seems justified in the light of the objective of avoiding an excessive and disproportionate administrative burden both for the competent national authorities and for producers with a low installed capacity. Furthermore, in view of the specific context of the emergency measures introduced by Regulation 2022/1854 and the particularly large number of transactions for which the competent authorities of the Member States have to ensure, within a narrow timeframe, (30) the enforcement of the cap on market revenues, the introduction of such a threshold was capable of ensuring the immediate and effective implementation of the measures adopted to address the energy crisis. (31) Moreover, the threshold of 1 MW adopted by the EU legislature is based on an objective criterion which allows a reasonable differentiation to be made between small producers, which are excluded from the cap mechanism, and other producers with larger production capacity, which remain subject to the levy.

60.      Similarly, I note that, given the economic and social context in which the cap was adopted, the EU legislature had broad discretion, in particular because its intervention involved political, economic and social choices and complex assessments and evaluations. (32) In my view, that discretion also extends to determining the parameters which define the scope of that cap, including the level of the threshold above which the undertakings concerned are subject to the levy provided for in Article 7(1) of Regulation 2022/1854. (33)

61.      Furthermore, I believe that the fact that, due to the threshold in question, only certain producers are subject to the levy is not, in itself, such as to call into question the reasonableness of the threshold of 1 MW. By definition, the existence of such a threshold could give rise to situations where operators subject to the levy are accorded different treatment (in particular in terms of whether or not a cap on revenues is applied), even though their situations, while objectively distinct, may, in practice, appear to be very similar or even almost identical. That consequence is inherent in, if not consubstantial with, any mechanism based on an objective criterion for delimiting situations, since it is impossible to take into account all the specific features of each individual case.

62.      Consequently, and in view of the broad discretion enjoyed by the EU legislature, I consider that it did not make a manifest error of assessment in providing for the possibility for Member States to apply a de minimis threshold and in setting the maximum for that threshold at 1 MW, without giving it any further flexibility.

63.      In the light of the foregoing, I am of the view that the answer to the third question must be that the first sentence of Article 7(3) of Regulation 2022/1854 must be interpreted as not infringing Articles 20 and 21 of the Charter in that it permits Member States not to apply the cap on market revenues laid down in Article 6(1) of that regulation to producers generating electricity with production facilities with an installed capacity of up to 1 MW, without providing for the possibility to introduce a progressive levy rate or to establish a derogation or exception based on the installed capacity of the facility concerned.

C.      Fourth question referred for a preliminary ruling

64.      By its fourth question, the referring court asks, in essence, whether Article 6(1) of Regulation 2022/1854 is valid in the light of Article 17 of the Charter in that it provides for a levy rate of 100% on surplus market revenues.

65.      I would recall that Article 17 of the Charter establishes the principle of protection of the right to property. According to the Court’s settled case-law, the protection afforded by that provision does not concern mere commercial interests or opportunities, the uncertainties of which are part of the very essence of economic activity, but concerns rights with an asset value creating an established legal position under the legal system concerned, enabling the holder to exercise those rights autonomously and for his or her own benefit. (34) As the Court has ruled, it is apparent from the case-law of the European Court of Human Rights (‘the ECtHR’) relating to Article 1 of Additional Protocol No 1 to the European Convention for the Protection of Human Rights and Fundamental Freedoms, signed in Rome on 4 November 1950 (‘the ECHR’), signed in Paris on 20 March 1952, which, like the ECHR, must be taken into consideration pursuant to Article 52(3) of the Charter as the minimum threshold of protection, that the concept of ‘possessions’ can include both ‘existing possessions’ and ‘assets’, including claims, in respect of which the applicant can argue that he or she has at least a ‘legitimate expectation’ of obtaining effective enjoyment of a property right. (35) However, the Court has also held, as is apparent from that case-law, that future income cannot be considered to constitute ‘possessions’ that may enjoy the protection of that article unless it has already been earned, it is definitely payable or there are specific circumstances that can cause the person concerned to entertain a legitimate expectation of obtaining an asset. (36)

66.      Before examining the validity of Article 6(1) of Regulation 2022/1854 in the light of Article 17 of the Charter, it must be determined whether the surplus revenues referred to in that provision satisfy the criteria identified by the case-law referred to above to be characterised as ‘possessions’ for its purposes and thus fall within the scope of Article 17 of the Charter. In my view, that conclusion is necessary. Since it is not disputed that the revenues subject to the cap were actually received by the producers concerned and were taken from them only subsequently, those revenues must be considered ‘possessions’ within the meaning of the abovementioned case-law, despite their exceptional and uncertain nature. They constitute income in respect of which the undertakings concerned could entertain a ‘legitimate expectation’, in the economic sense of the term, in that those revenues reflected prices and, consequently, the economic reality at the time in question. (37)

67.      According to the Court’s settled case-law, the right to property guaranteed in Article 17 of the Charter is not absolute and its exercise may be subject to restrictions justified by objectives of general interest pursued by the European Union. (38) In that regard, under Article 52(1) of the Charter, any limitation on the exercise of the rights and freedoms recognised by the Charter must be provided for by law, respect the essence of those rights and freedoms and, subject to the principle of proportionality, be necessary and genuinely meet objectives of general interest recognised by the European Union or the need to protect the rights and freedoms of others. It is also apparent from the case-law of the ECtHR that taxation is in principle an interference with the right guaranteed in the first subparagraph of Article 1 of Additional Protocol No 1 to the ECHR, since it deprives the person concerned of the amount of money which must be paid. (39) It also follows from that case-law that any interference with the right to property, including one resulting from a measure to secure payment of taxes, must strike a ‘fair balance’ between the demands of the general interest of the community and the requirements of the protection of the individual’s fundamental rights. (40) Thus, a financial liability arising out of the raising of taxes or contributions may adversely affect the right to property if it places an ‘excessive burden’ on the person or entity concerned or ‘fundamentally interferes with his, her or its financial position’. (41)

68.      Although it is not disputed that the cap introduced by Article 6(1) of Regulation 2022/1854 constitutes interference with the right to property of the producers concerned, I nevertheless consider that the conditions under which such interference may be accepted are met in this case.

69.      I would observe, first, that both the level of the cap and the detailed rules for the implementation of the levy rate of 100% on the revenues exceeding that cap are expressly laid down in that regulation and are set out in a clear, precise and detailed manner in its provisions. (42)

70.      I note, second, that, even though the levy rate is set at 100%, the essence of the right to property of the producers concerned continues to be safeguarded because only surplus revenues within the meaning of the regulation are subject to the levy and the cap was set at a level well above initial market expectations, thereby leaving a reasonable margin for the operators concerned. (43) I recall in that regard that the emergency measures adopted pursuant to the regulation do not apply to the assets of the undertakings concerned or to their ‘ordinary’ revenues, but are limited to the windfall profits generated by the energy crisis, which the producers concerned could not reasonably expect. (44)

71.      I observe, third, that the cap pursues an objective of general interest of the European Union. It is clear, in particular, from Articles 1 and 10 and recitals 6 and 46 of Regulation 2022/1854 that the levy on surplus revenues was introduced in order to allow them to be passed on in a targeted manner to final electricity customers with a view to financing support measures to mitigate the effects on them of exceptionally high electricity prices in a context characterised, in particular, by Russia’s war of aggression against Ukraine. That levy thus has a direct and clear link with the main objective pursued by the regulation. In addition, there is nothing in the order for reference to suggest that the levy rate of 100% on surplus revenues would not be appropriate for financing support measures for final electricity customers as provided for by the regulation.

72.      Fourth, as regards the principle of proportionality, I recall that that principle requires that measures adopted by European Union institutions do not exceed the limits of what is appropriate and necessary in order to attain the objectives legitimately pursued by the legislation in question; when there is a choice between several appropriate measures, recourse must be had to the least onerous, and the disadvantages caused must not be disproportionate to the aims pursued. (45)

73.      That assessment is borne out by the fact that the extraordinary measures introduced by the EU legislature in the context of Regulation 2022/1854 have a strictly limited temporal scope. (46) Indeed, without prejudice to the option available to Member States to adopt national measures outside the temporary period of application laid down by the regulation, Articles 6 and 8 thereof applied only between 1 December 2022 and 30 June 2023.

74.      Furthermore, as regards the degree of interference with the right to property in the light of the objective pursued, as noted in point 70 of this Opinion, although the levy rate for surplus revenues was set at 100%, that rate applies only to income exceeding the cap determined by the EU legislature and, as the case may be, by Member States. Revenues below that threshold were not affected at all by the cap. It should be noted that Regulation 2022/1854 offers Member States considerable discretion, permitting them, on the one hand, to limit the levy to 90% of the surplus revenues or to provide for a higher cap for producers with investment and operating costs above the cap set in Article 6(1) of that regulation and, on the other, to exclude certain specific categories of producers from that cap.

75.      It follows that, by providing that the objective of general interest pursued by Regulation 2022/1854, which is to mitigate the effects of exceptionally high electricity prices, is to be achieved through exceptional, targeted and time limited measures, the EU legislature ensured that the effects of the interference with the right to property of the undertakings concerned were limited and prevented the ensuing financial burden from being excessive.

76.      In the light of the foregoing, I am of the view that the answer to the fourth question must be that Article 6(1) of Regulation 2022/1854 must be interpreted as not infringing Article 17 of the Charter by providing that the surplus market revenues of the electricity producers listed in Article 7(1) of that regulation are subject to a levy rate of 100%.

D.      The fifth question referred for a preliminary ruling

77.      By its fifth question, the referring court asks, in essence, whether Article 6(1) and Article 8 of Regulation 2022/1854, read in the light of recital 40 thereof, must be interpreted as permitting Member States to introduce a cap on market revenues set at EUR 130/MWh, justified by the increase in prices on the Belgian electricity market.

78.      I must state at the outset that the referring court’s queries stem from the fact that Article 8(1) of Regulation 2022/1854, entitled ‘National crisis measures’, sets out the measures which may be adopted by Member States. It thus asks whether, as some of the applicants in the main proceedings submit, the introduction or maintenance by a Member State of one of the measures referred to in that provision is subject to the existence of characteristics or circumstances specific to the Member State concerned which are distinct from the general circumstance justifying the introduction by the regulation of the cap laid down in Article 6(1) thereof, which was, in essence, the increase in prices on the electricity market. In other words, that court asks whether Member States are required to establish the existence of particular circumstances justifying the adoption of national measures derogating from the cap laid down in Article 6(1) of the regulation.

79.      I note, in the first place, that, although Article 6(1) of Regulation 2022/1854 provides that market revenues of producers obtained from the generation of electricity from the sources referred to in Article 7(1) thereof are to be capped to a maximum of EUR 180/MWh of electricity produced, Article 8 of that regulation stipulates, inter alia, in paragraph 1(a), that Member States may maintain or introduce ‘measures that further limit the market revenues’ of producers generating electricity from those sources.

80.      In the light of the wording of those provisions and the broad discretion which Regulation 2022/1854 accords, in general, to Member States for its implementation, I do not think there is any doubt that those provisions permit Member States to introduce a cap on the revenues concerned at a level lower than the maximum cap of EUR 180/MWh laid down in Article 6(1) of that regulation, as is rightly submitted by the Belgian and Austrian Governments, the Council and the Commission. (47)

81.      That interpretation has, moreover, already been confirmed by the Court in the recent cases that led to the judgments in Secab (48) and in Electrabel and Others, (49) which concerned the compatibility with Regulation 2022/1854 of certain aspects of rules adopted by the Italian Republic and the Kingdom of Belgium, respectively, pursuant to that regulation.

82.      I note, in the second place, that the interpretation, advocated by some of the applicants in the main proceedings, that the introduction of a cap lower than the cap set by EU law is possible only where there are circumstances specific to a Member State justifying the adoption of national measures which derogate from those provided for in the regulation, finds no support in the wording of that regulation itself and is difficult to reconcile with its guiding principles and the objectives pursued by it.

83.      More specifically, with regard to recital 40 of the regulation, (50) which is mentioned by the referring court in its fifth question, I consider that the expression ‘specific conditions’ cannot be interpreted as requiring the existence of particular circumstances, which are distinct from those justifying the adoption of a cap at EU level, or as making the adoption of national measures subject to additional requirements applying to Member States. There is nothing in Article 8(1) of the regulation to suggest that the measures set out therein could be adopted by Member States only if they establish the existence of particular circumstances specific to their national markets, which are distinct from those on the basis of which the EU legislature justified the introduction of the cap on revenues laid down in Article 6(1) of Regulation 2022/1854. (51) It follows that, in so far as recital 40 of that regulation refers to ‘specific conditions’, they must be understood to mean the conditions set out in Article 8(2) of the regulation.

84.      Furthermore, such a reading would seem to be difficult to reconcile with the fact that, although a recital of an act of EU law may clarify its interpretation, it cannot, in any event, add conditions distinct from or supplementary to those by reference to which the Member States’ action is to be assessed, (52) and with the broad discretion which Regulation 2022/1854 seems to accord to Member States for its implementation.

85.      I would observe, in the third and last place, that the referring court is uncertain as to the level of the cap of EUR 130/MWh set by the Belgian Government. More specifically, it asks whether the fact that that cap is EUR 50/MWh lower than the cap laid down in Article 6(1) of Regulation 2022/1854 is such as to jeopardise the objectives pursued by the regulation, in particular the objective of safeguarding the interests of electricity producers.

86.      I wish to point out in that respect that, although Article 8(1) of that regulation permits Member States to introduce or maintain a cap lower than the cap of EUR 180/MWh laid down in Article 6(1) thereof, the discretion available to them is framed by the requirements set out in Article 8(2) of the regulation (which imposes certain limitations on national discretion in implementing the cap on revenues). By laying down a series of conditions to be respected, that provision seeks precisely to ensure that, when a Member State utilises that possibility, the cap adopted is not set arbitrarily (and that certain fundamental principles of EU energy law are safeguarded).

87.      It should be stated, however, that the specific assessment of respect for those conditions is essentially factual in nature and cannot be made in the abstract. Accordingly, the referring court must determine whether those conditions are satisfied in the dispute in the main proceedings. To that end, it will have to examine whether the cap was set at a level such as, first, to cover and recover the operating costs of the producers concerned and, second, to meet the expectations of a reasonable investor in order to avoid any unfavourable effects on investments. Such an examination will thus lead that court to assess whether the cap of EUR 130/MWh is consistent with the requirements of Article 8(2) of Regulation 2022/1854 in the light of the factual submissions made by the Belgian Government (53) and the criticisms raised by the applicants in the main proceedings. Recitals 27 to 29 of that regulation provide helpful guidance in that regard. (54)

88.      In the light of the foregoing, I am of the view that the answer to the fifth question must be that Article 6(1) and Article 8 of Regulation 2022/1854, read in the light of recital 40 thereof, must be interpreted as allowing Member States to introduce a measure by which a cap on market revenues is set at EUR 130/MWh, provided that the conditions set out in Article 8(2) of that regulation are complied with.

E.      The sixth question referred for a preliminary ruling

89.      By its sixth question, which is referred in the event that the fifth question is answered in the affirmative, the referring court asks about the validity of Article 6(1) and Article 8 of Regulation 2022/1854 in the light of Articles 16 and 17 of the Charter and the principle of energy solidarity. (55)

90.      I would make the preliminary point that, while the fourth question relates to the validity in the light of EU law of the cap introduced by Regulation 2022/1854, the sixth question concerns the validity in the light of provisions of the Charter of the cap laid down by Belgian law, which is set at EUR 130/MWh. In that regard, and in so far as that regulation does not itself lay down the cap of EUR 130/MWh at issue in the main proceedings, the analysis set out in the following points of this Opinion will be confined to assessing the validity of the provisions of the regulation mentioned by the referring court in so far as they permit a Member State, in accordance with the conditions set out in Article 8(2) thereof, to set a cap on revenues lower than the cap of EUR 180/MWh laid down in Article 6(1) of the regulation. I recall, to that effect, that the conditions in Article 8(2)(e) of Regulation 2022/1854 include the obligation for Member States to ensure that the national measures adopted under Article 8(1) are ‘compatible with Union law’, including with the Charter. (56)

1.      The validity of Article 6(1) and Article 8 of Regulation 2022/1854 in the light of Articles 16 and 17 of the Charter

91.      Article 16 of the Charter, which concerns the freedom to conduct a business, provides that that freedom is recognised in accordance with EU law and national laws and practices. According to the Court’s settled case-law, the protection afforded by that article includes, in particular, the freedom to exercise an economic or commercial activity, the freedom of contract and free competition, as well as the right for any business to be able freely to use, within the limits of its liability for its own acts, the economic, technical and financial resources available to it. (57) Furthermore, that freedom, which does not constitute an absolute right, may be subject to a broad range of interventions on the part of public authorities which may, in the public interest, limit the exercise of economic activity. That circumstance is reflected, in particular, in the way in which EU legislation should be assessed in the light of the principle of proportionality under Article 52(1) of the Charter. (58)

92.      I think it is important to bear in mind that the question whether the cap introduced by the Belgian Government could, in practice, infringe Article 16 of the Charter cannot be assessed in the abstract. On the contrary, such an assessment requires a specific examination of the circumstances of the case, for which the referring court alone has jurisdiction.

93.      In any case, I would observe that neither the option accorded to Member States by Article 8(1)(a) of Regulation 2022/1854 to set a cap on revenues lower than EUR 180/MWh nor the levy on ‘surplus’ revenues generated by exceptional circumstances, where it is implemented in accordance with the conditions laid down in Article 8(2) of that regulation, seems, as such, to be capable of affecting the investment capacity of the producers concerned or their freedom to exercise their economic activity. A possible infringement of Article 16 of the Charter could be accepted only if it were established that the cap imposed by national law is incompatible with Article 8(2) of Regulation 2022/1854, in particular because it jeopardised investment signals or did not permit the investments and operating costs of those producers to be covered. The referring court must therefore assess whether, in the light of all the information available to it, the cap on revenues laid down in Article 22b of the Law of 16 December 2022 actually satisfies the conditions set out in Article 8(2) of the regulation. (59)

94.      In any event, even if the Court were to find that the levy on surplus revenues, where it is applied on the basis of stricter rules than the cap of EUR 180/MWh laid down in Article 6(1) of Regulation 2022/1854, is such as to restrict the exercise of the freedom to conduct a business, that restriction would seem to be justified for the same reasons as are set out in points 69 to 74 of this Opinion. Any limitation on the freedom to conduct a business caused by imposing the levy on surplus revenues more strictly than the cap of EUR 180/MWh laid down by Article 6(1) of that regulation seems to respect the essence of that freedom, bearing in mind the conditions set out in Article 8(2) of the regulation, the fact that the levy applied only for a short period and that it did not hinder the business activity of the producers concerned.

95.      The foregoing analysis can also be applied to the part of the sixth question concerning the validity of the provisions of Regulation 2022/1854 identified by the referring court in the light of Article 17 of the Charter. (60)

2.      The validity of Article 6(1) and Article 8 of Regulation 2022/1854 in the light of the principle of energy solidarity

96.      As regards the principle of energy solidarity, I note that Article 194(1) TFEU provides that, in the context of the establishment and functioning of the internal market and with regard for the need to preserve and improve the environment, EU policy on energy aims, in a spirit of solidarity between Member States, to ensure the functioning of the energy market, ensure security of energy supply in the European Union, promote energy efficiency and energy saving and the development of new and renewable forms of energy and promote the interconnection of energy networks. Thus, the spirit of solidarity between Member States, mentioned in that provision, constitutes a specific expression, in the field of energy, of the principle of solidarity, which is itself one of the fundamental principles of EU law, and is closely linked to the principle of sincere cooperation, laid down in Article 4(3) TEU. (61) Furthermore, there is nothing that would permit the inference that the principle of solidarity referred to in Article 194(1) TFEU cannot, as such, produce binding legal effects on the Member States and the EU institutions. On the contrary, that principle, as is apparent from the very wording and structure of that provision, forms the basis of all of the objectives of the European Union’s energy policy, serving as the thread that brings them together and gives them coherence. (62) It follows, in particular, that acts adopted by the EU institutions under that policy must be interpreted, and their legality assessed, in the light of that principle. (63)

97.      It should also be noted that the principle of energy solidarity must be taken into account by the EU institutions and by the Member States, in the context of the establishment and functioning of the internal market and, in particular, the internal market in natural gas, by ensuring security of energy supply in the European Union, which means not only dealing with emergencies when they arise, but also adopting measures to prevent crisis situations. To that end, it is necessary to assess whether there are risks for the energy interests of the Member States and the European Union, and in particular to security of energy supply, before going on to conduct the analysis of the interests involved in the light of that principle, taking into account the interests both of the Member States and of the European Union as a whole. However, the application of that principle does not mean that EU energy policy must never, under any circumstances, have negative impacts on the particular interests of a Member State in that field. (64) Nevertheless, as has been pointed out in the preceding point of this Opinion, the EU institutions and the Member States are required to take into account, in the context of the implementation of that policy, the interests both of the European Union and of the various Member States that are liable to be affected and to balance those interests where there is a conflict. (65)

98.      In the present case, Regulation 2022/1854 was adopted on the basis of Article 122(1) TFEU, which comes under Chapter 1, entitled ‘Economic policy’, of Title VIII of Part Three of the FEU Treaty. However, it cannot be inferred solely from the choice of that legal basis by the EU legislature that that act falls outside the scope of EU energy policy or that, for that reason, its lawfulness could not be assessed by reference to the principle of energy solidarity. (66)

99.      Thus, in so far as it follows from the Court’s case-law recalled in the preceding point of this Opinion that the principle of energy solidarity must inform any action relating to EU energy policy, including in a crisis situation, and that it applies to both the EU institutions and the Member States, entailing the adoption of measures to deal with emergencies and to prevent crises, there is little doubt, in my view, that Regulation 2022/1854 illustrates the ‘spirit of solidarity’ mentioned in Article 194(1) TFEU. As a well-coordinated EU-wide response to the stark increase of electricity prices and their effects on households and industry, which was adopted, in particular, in order to avoid the adoption of uncoordinated national measures which could damage the internal energy market and jeopardise security of supply, the regulation is itself based on the principle of solidarity and even constitutes a concrete expression of that principle. (67)

100. Furthermore, I note that, contrary to what is argued by some applicants in the main proceedings, the fact that Regulation 2022/1854 permits the introduction of different caps for each Member State or the fact that some of them have utilised that option to determine caps lower than the cap laid down in Article 6(1) of that regulation cannot, in itself, be regarded as an infringement of the principle of energy solidarity. It is true that the intervention by the EU legislature was intended to prevent a fragmentation of the EU electricity market by laying down a set of common rules, in particular by introducing a ‘uniform cap across the Union’, as is stated in recital 27 of the regulation. However, the harmonisation sought was neither maximum harmonisation nor exhaustive harmonisation. On the contrary, the EU legislature took into account the specific features of the electricity markets of the different Member States. The objective pursued was not therefore to impose a uniform cap across the European Union, but to ensure the establishment of a mechanism applying a cap on surplus revenues in all the Member States, subject to a common maximum cap.

101. Accordingly, by permitting Member States, under the conditions set out in Article 8 of Regulation 2022/1854, to set a cap on market revenues lower than the cap laid down in Article 6(1) thereof, the EU legislature did not infringe that principle.

102. In the light of the foregoing, I am of the view that the answer to the sixth question must be that Article 6(1) and Article 8 of Regulation 2022/1854 must be interpreted as permitting Member States to provide for a cap lower than the cap laid down in Article 6(1) thereof and as not infringing Articles 16 and 17 of the Charter or the principle of energy solidarity.

F.      The seventh question referred for a preliminary ruling

103. By its seventh question, the referring court asks, in essence, whether Article 6(1) and Article 7(1)(e) of Regulation 2022/1854 infringe Articles 20 and 21 of the Charter, the principles of legal certainty and the protection of legitimate expectations, as well as the obligation to state reasons provided for in Article 296 TFEU, in that they also apply the compulsory cap on market revenues of EUR 180/MWh to the sale of electricity produced from biomass fuels (solid or gaseous biomass fuels).

1.      The validity of the cap in the light of Articles 20 and 21 of the Charter

104. With regard, in the first place, to the part of the question relating to the validity of Article 6(1) and Article 7(1)(e) of Regulation 2022/1854 in the light of Articles 20 and 21 of the Charter, the referring court considers that that question has to be examined because the contested provisions apply the cap of EUR 180/MWh to all undertakings producing electricity from biomass, even though there are significant differences between those undertakings and undertakings producing electricity from other technologies, particularly with regard to their investment and operating costs, which could give rise to an unjustified difference in treatment between those different producers.

105. I would point out that, on the basis of a combined reading of Article 6(1) and Article 7(1)(e) of Regulation 2022/1854, revenues from the production of electricity from solid or gaseous biomass fuels, except for biomethane, must, in the same way as revenues obtained from the other energy sources listed in Article 7(1) of that regulation, be subject to the cap of EUR 180/MWh. In taking that approach, the EU legislature considered that the use of solid or gaseous biomass fuels did not expose the electricity producers concerned to production costs comparable to those borne by the producers particularly affected by the exceptional rise in gas prices as an input, with the result that the former producers could essentially be classified in the category of ‘inframarginal generators’ to which the cap applies. (68)

106. I would also like to point out that one of the main objectives of Regulation 2022/1854 was to cap market revenues from the sale of electricity produced by the producers with the lowest marginal costs, which were likely to generate substantial surplus revenues. The levy on those revenues was intended to permit Member States to finance support measures for final electricity customers. (69)

107. Furthermore, I consider that the broad discretion enjoyed by the EU legislature in adopting emergency measures like those laid down in Regulation 2022/1854 allows it to group electricity producers subject to the cap within a general category based on the energy source used for electricity generation and thus to treat different types of solid or gaseous fuels uniformly, without being required to make a finer differentiation between the various forms of biomass referred to in Article 7(1) of that regulation. It is not disputed that some of the producers subject to the cap bear higher production costs than others. However, that fact cannot, in itself, call into question the EU legislature’s categorisation of different electricity producers. The definition of categories necessarily entails a degree of generalisation which does not allow every specific situation to be taken into account. In so far as those categories were based on objective criteria, the EU legislature cannot be found to be at fault for proceeding as it did. In my view, following the arguments put forward by the applicants in the main proceedings would amount to requiring separate caps to be established for each energy source, a solution which is certainly conceivable, but which would, in practice, be likely to complicate the application of the cap mechanism and undermine its effectiveness.

108. In view of the objective pursued by Regulation 2022/1854, which was described in point 107 of this Opinion, and the specific economic and political context in which it was adopted, the EU legislature did not make a manifest error of assessment in taking the view that, despite the differences between the energy sources referred to in Article 7(1) of that regulation, they should be subject to the same cap because they were all identified as being inframarginal technologies.

2.      The obligation to state reasons

109. As regards, in the second place, the obligation to state reasons provided for in the second paragraph of Article 296 TFEU, I recall that, according to the Court’s settled case-law, the reasons stated must be appropriate to the measure at issue and must disclose in a clear and unequivocal fashion the reasoning followed by the institution that adopted that measure in such a way as to enable the persons concerned to ascertain the reasons for it and to enable the EU judicature to exercise its power of review. Moreover, it is not necessary for the reasoning to go into all the relevant facts and points of law, since the question whether the statement of reasons for a measure meets the requirements of that provision must be assessed with regard not only to its wording but also to its context and to all the legal rules governing the matter in question. (70) In addition, the scope of that obligation depends on the nature of the measure in question and, in the case of measures intended to have general application, the statement of reasons may be limited to setting out the overall situation which led to its adoption, on the one hand, and the general objectives which it is intended to achieve, on the other. In that context, the Court has held, in particular, that if the contested measure clearly discloses the essential objective pursued by the institution, it would be excessive to require a specific statement of reasons for the various technical choices made. (71)

110. For the reasons explained in the next point of this Opinion, I believe that the EU legislature complied with its obligation to state reasons in this case.

111. As regards, first of all, the EU legislature’s decision to set the cap at EUR 180/MWh, I note that the reasons for choosing that level and the specific factors on which that choice is based can be identified clearly and sufficiently precisely from the very wording of Regulation 2022/1854, recitals 27 to 30 thereof in particular. Second, with respect to the list of energy sources in Article 7(1) of the regulation which are subject to the cap, recitals 11 and 32 to 34 thereof also provide sufficient explanations in that regard. Lastly, although the regulation does not contain a specific statement of reasons for applying the cap for each of the energy sources concerned, the determining criterion adopted for the application of that measure, namely the differentiation between the inframarginal technologies which are subject to the cap and those with higher costs which are excluded from it, can nevertheless be identified sufficiently clearly and precisely from that regulation. A more in-depth examination of whether certain technologies fall, in the present case, within the notion of ‘inframarginal technologies’ goes beyond the requirements flowing from the obligation to state reasons, due to its highly technical nature.

3.      The principles of legal certainty and the protection of legitimate expectations

112. As regards, in the third and last place, the principles of legal certainty and the protection of legitimate expectations, I note that the first of those principles requires that the rules of law be clear and precise and that their application be foreseeable for those subject to the law, in particular where they may have adverse consequences. The principle of legal certainty requires, inter alia, that legislation must enable those concerned to know precisely the extent of the obligations imposed on them, and those persons must be able to ascertain unequivocally their rights and obligations and take steps accordingly. (72) However, those requirements cannot be interpreted as precluding the EU legislature from having recourse, in a norm that it adopts, to an abstract legal notion; this seems obvious in so far as it is not possible to determine in advance, precisely and specifically, all situations that might arise. Similarly, the principle of legal certainty does not include an obligation to maintain the legal order unchanged over time, since the EU legislature remains free, within the limits of its discretion, to alter the existing legislative situation. (73) Excessive legislative rigidity would therefore hinder adaptation to any new circumstance that may arise.

113. As regards the principle of the protection of legitimate expectations, the right to rely on that principle presupposes that precise, unconditional and consistent assurances originating from authorised, reliable sources have been given to the person concerned by the competent authorities of the European Union. However, a person may not plead breach of the principle unless he or she has been given precise assurances by the authorities. Similarly, an economic operator may not place legitimate reliance on there being no alteration of an existing situation by the EU legislature. (74)

114. For the reasons explained in the next few points of this Opinion, I consider that no infringement of those principles by Article 6(1) and Article 7(1)(e) of Regulation 2022/1854 can be established.

115. First, as far as the principle of legal certainty is concerned, I note that those two provisions define sufficiently clearly and precisely both the scope of the cap and the detailed rules for its implementation. (75) They therefore enable the producers concerned to determine sufficiently precisely the extent of their obligations in accordance with the case-law mentioned in point 112 of this Opinion. (76) Furthermore, because, according to that case-law, the principle of legal certainty does not require the maintenance of the legal order unchanged, the EU legislature cannot be found to be at fault for having adopted, in the context of an emergency, exceptional measures to address the energy crisis.

116. Second, as far as the principle of the protection of legitimate expectations is concerned, as is clear from the Court’s case-law set out in point 113 of this Opinion, any economic operator may rely on that principle where a competent EU authority has created reasonable expectations for it through precise, unconditional and consistent assurances. In the present case, it is clear that none of the applicants in the main proceedings claims that the EU legislature had given such assurances regarding the exclusion of market revenues from the sale of electricity produced from solid or gaseous biomass fuels (excluding biomethane) from the scope of the cap. (77)

117. It follows that neither the principle of legal certainty nor the principle of the protection of legitimate expectations can be interpreted as precluding any intervention by the public authorities to remedy a market failure, in particular where that intervention is an urgent response to an event which is exceptional and therefore, by definition, unforeseeable. Furthermore, the undertakings concerned cannot legitimately rely on the maintenance of an existing legal or economic situation, which can be altered within the framework of the exercise of the discretion available to the competent EU authorities.

118. In the light of the foregoing, I am of the view that the answer to the seventh question must be that Article 6(1) and Article 7(1)(e) of Regulation 2022/1854 must be interpreted as not infringing Articles 20 and 21 of the Charter, the principles of legal certainty and the protection of legitimate expectations or the obligation to state reasons provided for in Article 296 TFEU, in that they also make revenues from the sale of electricity produced from biomass fuels subject to the cap of EUR 180/MWh.

G.      The eighth question referred for a preliminary ruling

119. By its eighth question, the referring court asks, in essence, whether Article 8(1)(b) and (2) of Regulation 2022/1854 should be interpreted as requiring Member States  to set a higher cap on market revenues for facilities producing electricity from solid or gaseous biomass fuels than the EUR 180/MWh cap provided for in Article 6(1) of that regulation.

120. I would observe as a preliminary point that, although the Belgian Government introduced a cap set at EUR 130/MWh for all operators producing electricity from one of the energy sources listed in Article 7(1) of Regulation 2022/1854, it nevertheless considered it necessary, in view of the higher costs borne by producers of electricity from solid or gaseous biomass fuels compared with the other energy sources subject to that cap, to raise the cap for the latter to EUR 180/MWh. (78) The applicants in the main proceedings submit, however, that the uniform application of a cap of EUR 180/MWh to all undertakings producing electricity from biomass is not justified. They claim in that regard, first, that there are substantial differences between those producers in terms of their investments and operating costs and, second, that such a measure has a disproportionate impact on the capacity of producers using biomass waste to cover those costs. In their view, the EU legislature should therefore have set the cap at a level higher than EUR 180/MWh.

121. I note in that respect that, although Article 8(1)(b) of Regulation 2022/1854 actually permits Member States  to derogate from the ‘maximum’ cap of EUR 180/MWh laid down in Article 6(1) thereof by setting a higher cap, that option is in no way mandatory. Indeed, it must be concluded that utilising that option remains subject to the condition that the investments and operating costs of the producers concerned exceed the cap of EUR 180/MWh set in Article 6(1) of that regulation. Recital 42 of the regulation states, moreover, that that possibility is intended to ensure the security of supply.

122. Consequently, the Member States must determine, in the light of the specific characteristics of their national markets and on the basis of objective data relating to the production costs of the facilities concerned, whether it is appropriate to have recourse to that option. It should be noted in that regard that, although the producers concerned allege that the Belgian Government set a cap which does not allow their investments and operating costs to be covered, such a conclusion – which is based on a factual assessment falling outside the jurisdiction of the Court – is not established or, in any event, is not clear from the order for reference. (79)

123. As regards Article 8(2) of Regulation 2022/1854, which is also mentioned in the eighth question, that provision is intended to regulate the discretion enjoyed by Member States in adopting national caps by laying down the criteria which those measures must satisfy in order to be compatible with the regulation. I would point out in that respect that, although Article 8(2) of the regulation requires that national measures adopted by Member States ensure, inter alia, that investments and operating costs are covered, the assessment of the reasonableness of the cap applied by the Belgian Government for producers of electricity from biomass is a matter of factual analysis falling outside the jurisdiction of the Court. (80)

124. In the light of the foregoing, I am of the view that the answer to the eighth question must be that Article 8(1)(b) of Regulation 2022/1854 must be interpreted as not requiring Member States to set a higher cap on market revenues for facilities producing electricity from solid or gaseous biomass fuels than the EUR 180/MWh cap provided for in Article 6(1) of that regulation, provided the conditions laid down in Article 8(2) thereof are respected.

H.      The tenth and twelfth questions referred for a preliminary ruling

125. By its tenth question, the referring court asks, in essence, whether Article 2(5) and Article 6(1) of Regulation 2022/1854, read in the light of recital 30 thereof, permit, with regard to the use of presumptions, a differentiation between producers of electricity from nuclear energy and producers of electricity from other sources. If so, that court wishes to know, by its twelfth question, whether those provisions infringe Articles 20 and 21 of the Charter.

126. I note, in the first place, that the tenth question essentially corresponds to the second question asked by the cour d’appel de Bruxelles (Court of Appeal, Brussels, Belgium) in the case giving rise to the judgment in Electrabel and Others. (81) In that judgment, the Court ruled that Articles 6 to 8 of Regulation 2022/1854 must be interpreted as not precluding national legislation under which the amount of revenue to which a cap on market revenue provided for in Article 8 applies is determined, depending on the electricity generation facilities concerned, either on the basis of irrebuttable presumptions or on the basis of rebuttable presumptions, but which can only be rebutted, first, by justifying the actual revenues generated by all of the facilities of the operator concerned and, secondly, by means of other presumptions, provided that those presumptions make it possible to obtain reasonable estimates of those revenues which are representative of the reality of the market during the period in question. (82)

127. The Court held in that regard that the specific assessment of whether a given presumption meets that condition is a matter of fact and therefore falls within the jurisdiction of the national authorities, acting under the supervision of the national courts. It nevertheless stated, in order to assist the referring court in its assessment, that, for the purposes of that assessment, account must be taken of all the factual and technical factors characterising not only the situation of the operators and installations concerned, but also the national electricity market. (83) Those factors may include, in particular, the extent, taking into account those specific features, of the obstacles to the collection and verification of data which would make it possible to determine, within a timeframe compatible with the urgency of achieving the objective of protecting final electricity customers, the exact revenues of the installations or operators subject to the cap measure in question, as well as whether the presumptions made are sufficiently accurate to avoid a significant overestimate or underestimate of the revenues generated by the operators concerned, and whether there is a corrective mechanism allowing, where appropriate, for operators or national authorities to claim actual revenues in order to rectify the result of those presumptions if they do not lead to reasonable estimates that are representative of the reality of the market during the period in question. (84)

128. The Court also held in the judgment in Electrabel and Others that the fact that a Member State has chosen, where appropriate, to establish, on the basis of objective distinguishing factors, different presumptions depending on the operators, the installations or the technologies concerned, or a series of presumptions, does not establish that the condition set out in the previous point of this Opinion is not satisfied, provided that, for each of the categories of operators, installations or technologies that may be concerned, the presumption established makes it possible to obtain a reasonable estimate of the revenue specific to that category.

129. Thus, the Court’s case-law recalled in the preceding points of this Opinion indicates that the tenth question should be answered in the affirmative. Article 2(5) and Article 6(1) of Regulation 2022/1854, read in the light of recital 30 thereof, do not preclude, with regard to the use of presumptions, a differentiation between producers of electricity from nuclear energy and producers of electricity from other sources. However, it is for the referring court to determine that that differentiation is based on objective factors leading to a reasonable estimate of the revenues specific to each of the categories concerned.

130. In the second place, as regards the validity of Article 2(5) and Article 6(1) of Regulation 2022/1854 in the light of Articles 20 and 21 of the Charter, I recall that the principles of equal treatment and non-discrimination, which are enshrined in those two latter provisions, respectively, require that comparable situations must not be treated differently and different situations must not be treated in the same way unless such treatment is objectively justified. (85)

131. Even if, as some of the applicants in the main proceedings submit, producers of electricity from nuclear energy and producers of electricity from other sources are in a comparable situation having regard to the objective of capturing the surplus revenues realised by producers using ‘inframarginal’ technologies, that fact alone cannot, in my view, prevent the competent national authorities, particularly given the broad discretion available to them, having recourse to separate calculation methods in order to determine the revenues subject to the cap and, to that end, applying different presumptions depending on the categories of facilities concerned. That is the case, inter alia, where such a differentiation is based on objective considerations of a practical nature and on the need to ensure the effective enforcement of the cap, particularly by simplifying the arrangements for its implementation and reducing the administrative burden on the competent national authorities. (86) I note that in the present case the differentiation made by the Belgian legislature between electricity from nuclear energy and energy produced from other energy sources is based on the fact that, for the former category, the sales strategy of the producers concerned was regulated by the Law of 16 December 2022.

132. In the light of the foregoing, I am of the view that the answer to the twelfth question must be that Article 2(5) and Article 6(1) of Regulation 2022/1854, read in the light of recital 30 thereof, must be interpreted as not infringing Articles 20 and 21 of the Charter, in so far as they permit a Member State which uses presumptions for determining the market revenues subject to the cap to differentiate between producers of electricity from nuclear energy and producers of electricity from other sources.

I.      Thirteenth and fourteenth questions referred for a preliminary ruling

133. By its thirteenth question, the referring court asks, in essence, whether Article 6(1), Articles 7 and 8 and Article 22(2)(c) of Regulation 2022/1854 must be interpreted as permitting Member States to introduce a national cap on market revenues with effect from 1 August 2022. By its fourteenth question, which is asked in the event that the thirteenth question is answered in the affirmative, that court seeks to ascertain whether the provisions referred to above of that regulation are valid in the light of the principles of legal certainty, the protection of legitimate expectations, non-retroactivity of legal rules, energy solidarity and Article 17 of the Charter.

134. It is clear from the order for reference that those questions have their basis in the fact that the levy introduced by the Law of 16 December 2022 was applied to surplus revenues realised in Belgium during the period between 1 August 2022 and 30 June 2023, whereas Regulation 2022/1854 did not enter into force until 8 October 2022, the cap set by it was applicable only for the period from 1 December 2022 to 30 June 2023, and the regulation did not expressly provide for the possibility for Member States to apply that cap before 1 December 2022, although that option had been envisaged in the proposal which led to the adoption of the regulation.

135. I note, from the outset, that this issue was raised in the case giving rise to the judgment in Electrabel and Others. (87) The Court ruled that the provisions mentioned in the thirteenth question referred for a preliminary ruling, read in conjunction with Article 288 TFEU and the principles of the primacy and effectiveness of EU law and sincere cooperation, had to be interpreted as not precluding national legislation adopted after the entry into force of Regulation 2022/1854 which provides for the application of a measure capping market revenue similar to that imposed by that regulation, but for a period prior to that laid down by that regulation. (88) In that regard, it noted in particular that nothing in the regulation indicated that it would apply to such legislation or that it would make the adoption of such legislation subject to the conditions laid down in that regulation. (89) It also observed that Member States must exercise their powers in compliance with EU law, but it did not appear from the request for a preliminary ruling that the referring court in that case had any doubts as to the substantive compatibility of the national legislation at issue in the main proceedings with other provisions of EU law which may be applicable ratione temporis. (90)

136. Having clarified that point, the analysis and the answer provided by the Court in the judgment in Electrabel and Others, as summarised in the preceding point of this Opinion, should therefore be transposed and the thirteenth question should be answered in the affirmative.

137. Given the answer I propose to give to the thirteenth question, an answer must also be given to the fourteenth question. For the same reasons as those set out in points 112 to 118 of this Opinion, I am of the view that Article 6(1), Articles 7 and 8 and Article 22(2)(c) of Regulation 2022/1854 cannot be held to infringe the principles of legal certainty and the protection of legitimate expectations. The same holds for Article 17 of the Charter and the principle of energy solidarity, for the same reasons as are set out in points 69 to 75, 99 and 100 of this Opinion.

138. Having regard to the foregoing, I am of the view that the answer to the fourteenth question must be that Article 6(1), Articles 7 and 8 and Article 22(2)(c) of Regulation 2022/1854 must be interpreted as not infringing the principles of legal certainty and the protection of legitimate expectations, the non-retroactivity of legal rules, energy solidarity and Article 17 of the Charter.

J.      The fifteenth question referred for a preliminary ruling

139. By its fifteenth question, the referring court asks, in essence, whether EU law should be interpreted as preventing that court from upholding the effects of the Law of 16 December 2022 in the event that it found, in the light of the answers provided by the Court, that that Law is incompatible with the obligations arising from Regulation 2022/1854.

140. In the light of the answers I propose to give to the preceding questions referred for a preliminary ruling, there is no need to answer that fifteenth question. The following analysis is therefore presented for the sake of completeness, should the Court consider it appropriate to rule on that question.

141. I would like to observe as a preliminary remark that the referring court is not seeking a limitation in time of the effects of the forthcoming judgment, but asks about the possibility of maintaining in its national legal order the effects of the Law of 16 December 2022, even if it finds that Law to be incompatible with Regulation 2022/1854.

142. In that regard, I observe that it is for the authorities of the Member State concerned to take all appropriate measures, whether general or particular, to ensure that EU law is complied with in that state. (91) Thus, the Court has repeatedly ruled that, under the principle of sincere cooperation laid down in Article 4(3) TEU, Member States are required to nullify the unlawful consequences of an infringement of EU law, and that obligation is owed, within the sphere of its competence, by every organ of the Member State concerned, including by national courts before which an action against a national measure which is in breach of EU law has been brought. (92) Therefore, where the authorities of the Member State concerned find that national legislation is incompatible with EU law, while they retain the choice of the measures to be taken, they must ensure that national law is brought into line with EU law as soon as possible, and that the rights which individuals derive from EU law are given full effect. (93) If national courts had the power to give provisions of national law primacy in relation to EU law contravened by those provisions, even temporarily, the uniform application of EU law would be undermined. (94)

143. It is only purely exceptionally and on the basis of overriding considerations of legal certainty that the Court has recognised the possibility of allowing the temporary suspension of the ousting effect of a rule of EU law with respect to national law that is contrary thereto. Such a restriction on the temporal effects of the interpretation of that law, made by the Court, may be granted only in the actual judgment ruling upon the interpretation requested. (95)

144. Accordingly, the Court has recognised that, if domestic law allows it, a national court may maintain the effects of measures held to be incompatible with EU law where such maintenance is justified by overriding considerations relating to the need to nullify a genuine and serious threat of interruption in the electricity supply in the Member State concerned, which cannot be remedied by any other means or alternatives, particularly in the context of the internal market, and continues only for as long as is strictly necessary to remedy the breach. (96) The Court has also acknowledged in essence that, while taking into account the existence of an overriding consideration relating to the protection of the environment, a national court may exceptionally be authorised to make use of national legislation empowering it to maintain certain effects of a national measure the procedure for the adoption of which did not comply with an environmental directive, where there is a risk that the annulment of that measure could create a legal vacuum that is incompatible with that Member State’s obligation to adopt measures to transpose another act of EU law concerning the protection of the environment. (97)

145. In the present case, it is clear both from the order for reference and from the written observations submitted by the Belgian Government that, in support of its request for the maintenance of the effects of the Law at issue, that Member State invokes, first, the budgetary and administrative problems which would result from unmodulated annulment of that Law. (98) Second, that government claims that such annulment could create a legal vacuum in the absence of any applicable capping mechanism, thereby jeopardising the attainment of the objectives pursued by Regulation 2022/1854.

146. It must be noted, however, that the budgetary and administrative issues claimed by that government cannot, by themselves, be treated as overriding considerations within the meaning of the case-law referred to above. The Court has already ruled that merely referring to the budgetary and administrative problems which might arise from the annulment of the contested provisions is not sufficient to establish overriding considerations of legal certainty. (99) Along similar lines, the Court has also ruled that the financial consequences which might ensue for a Member State from a judgment delivered by way of a preliminary ruling do not in themselves justify a limitation on the temporal effects of the ruling. (100)

147. Consequently, none of the reasons put forward by the Belgian Government is capable of justifying the maintenance of the effects of the Law of 16 December 2022. (101) Moreover, the effect of such maintenance, as some of the applicants in the main proceedings submit, would be to extend the application of national provisions which are incompatible with EU law and capable of giving rise to serious interferences with the rights conferred on the undertakings concerned, in particular their right to effective judicial protection. (102)

V.      Conclusion

148. In the light of the foregoing considerations, I propose that the Court of Justice answer the questions referred for a preliminary ruling by the Grondwettelijk Hof (Constitutional Court, Belgium) as follows:

(1)      Article 7(1)(e) of Council Regulation (EU) 2022/1854 of 6 October 2022 on an emergency intervention to address high energy prices

must be interpreted as meaning that only revenues from the sale of electricity produced from biomethane, except for electricity produced from biogas through such a process using a cogeneration plant, are excluded from the scope of the cap laid down in Article 6 of that regulation. Such an interpretation is not contrary to Articles 20 and 21 of the Charter of Fundamental Rights of the European Union.

(2)      The first sentence of Article 7(3) of Regulation 2022/1854

must be interpreted as not infringing Articles 20 and 21 of the Charter in that it permits Member States not to apply the cap on market revenues laid down in Article 6(1) of that regulation to producers generating electricity with production facilities with an installed capacity of up to 1 MW, without providing for the possibility to introduce a progressive levy rate or to establish a derogation or exception based on the installed capacity of the facility concerned.

(3)      Article 6(1) of Regulation 2022/1854

must be interpreted as not infringing Article 17 of the Charter by providing that the surplus market revenues of the electricity producers listed in Article 7(1) of that regulation are subject to a levy rate of 100%.

(4)      Article 6(1) and Article 8 of Regulation 2022/1854

must be interpreted as allowing Member States to introduce a cap on market revenues set at EUR 130/MWh, provided that the conditions set out in Article 8(2) of the regulation are complied with.

(5)      Article 6(1) and Article 8 of Regulation 2022/1854

must be interpreted as permitting Member States to provide for a cap lower than the cap laid down in Article 6(1) thereof and as not infringing Articles 16 and 17 of the Charter or the principle of energy solidarity.

(6)      Article 6(1) and Article 7(1)(e) of Regulation 2022/1854

must be interpreted as not infringing Articles 20 and 21 of the Charter, the principles of legal certainty and the protection of legitimate expectations or the obligation to state reasons provided for in Article 296 TFEU, in that they also make revenues from the sale of electricity produced from biomass fuels subject to the cap of EUR 180/MWh.

(7)      Article 8(1)(b) of Regulation 2022/1854

must be interpreted as not requiring Member States to set a higher cap on market revenues for facilities producing electricity from solid or gaseous biomass fuels than the EUR 180/MWh cap provided for in Article 6(1) of that regulation, provided that the conditions laid down in Article 8(2) thereof are respected.

(8)      Article 2(5) and Article 6(1) of Regulation 2022/1854

must be interpreted as not infringing Articles 20 and 21 of the Charter, in so far as they permit a Member State which uses presumptions for determining the market revenues subject to the cap to differentiate between producers of electricity from nuclear energy and producers of electricity from other sources.

(9)      Article 6(1), Articles 7 and 8 and Article 22(2)(c) of Regulation 2022/1854

must be interpreted as not infringing the principles of legal certainty and the protection of legitimate expectations, the non-retroactivity of legal rules, energy solidarity and Article 17 of the Charter.

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1      Original language: French.

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2      Council Regulation of 6 October 2022 on an emergency intervention to address high energy prices (OJ 2022 L 261 I, p. 1). More precisely, reference is made to Article 2(5), Article 6(1), Articles 7 and 8 and Article 22(2)(c) of Regulation 2022/1854, read, as the case may be, in the light of recitals 30 and 40 thereof.

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3      They are, respectively, 2Valorise Ham NV, 2Valorise Amel NV and 2 Valorise NV (together ‘2Valorise and Others’); Luminus NV, EDF Belgium NV, ActiVent Wallonie NV, e-NosVents NV, CVLumiwind and Luminus Wind Together cv (together ‘Luminus and Others’); Rouge Lux BVBA and Biospace CV; Federatie van de Belgische Elektriciteits-en Gasbedrijven, Organisatie voor Duurzame Energie Vlaanderen VZW and Wind4wallonia 2 NV (together ‘FEBEG and Others’); Electrabel NV, and Eoly Energy NV (‘Eoly’).

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4      See, in that regard, judgments of 18 December 2025, Electrabel and Others (C‑633/23, ‘the judgment in Electrabel and Others’, EU:C:2025:991), and of 22 January 2026, Secab (C‑423/23, ‘the judgment in Secab’, EU:C:2026:32), cases in which I drafted the Opinions. See also my Opinion delivered on 25 June 2026 in Axpo Energy Romania and PPC Renewables Romania (C‑251/24 and C‑392/24). I would also point out that there are other cases still pending before the Court, in particular Varo Energy Belgium and Others (C‑358/24), Vermilion Energy Ireland and Others (C‑533/24), and Acea Produzione and Others (C‑153/25), in which my Opinions will be presented on 22 October 2026. The regulation is, moreover, the subject of several actions for annulment currently pending before the General Court. See, in that connection, Electrawinds Shabla South v Council (T‑759/22), Vermilion Energy Netherlands and Others v Council (T‑775/22), Vermilion Exploration and Production Ireland and Vermilion Energy Ireland v Council (T‑795/22), ExxonMobil Producing Netherlands and Mobil Erdgas Erdöl v Council (T‑802/22), and Petrogas E&P Netherlands v Council (T‑803/22).

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5      Communication from the Commission to the European Parliament, the European Council, the Council, the European Economic and Social Committee and the Committee of the Regions of 18 May 2022 entitled ‘RePowerEU Plan’ (COM(2022) 230 final; ‘the REPowerEU Plan’).

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6      Moniteur belge of 11 May 1999, p. 16264.

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7      Moniteur belge of 22 December 2022, p. 98819.

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8      Moniteur belge of 28 February 2003, p. 9879.

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9      For the purposes of this targeted Opinion, which addresses the question of presumptions only as an incidental issue, paragraph 5 of Article 22b of the Law of 16 December 2022 has been summarised. For its full version, see Moniteur belge of 22 December 2022, p. 98819, or the judgment in Electrabel and Others (paragraph 13).

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10      Directive of the European Parliament and of the Council of 11 December 2018 on the promotion of the use of energy from renewable sources (OJ 2018 L 328, p. 82).

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11      The national court refers in that regard to the judgment of 15 July 2021, Germany v Poland (C‑848/19 P, ‘the judgment in Germany v Poland’, EU:C:2021:598, paragraphs 37 to 53).

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12      The thirteenth question, which is not covered by this targeted Opinion, is worded as follows: ‘Should Articles 6(1), 7, 8 and 22(2)(c) of Regulation [2022/1854] be interpreted as permitting Member States to introduce a national measure whereby, like Article 5 of the [Law of 16 December 2022], the cap on market revenues is applied before 1 December 2022, namely on 1 August 2022?’

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13      According to the order for reference, that question arises in the light of the specific situation only of the applicants in the main proceedings which produce electricity from biogas, namely Rouge Lux and Biospace. Those producers state that their electricity generation activity is ancillary to their main activity in the agricultural sector. They explain in that regard that they do not purify biogas before it is used to power their electricity generation facilities for two reasons: first, the cogeneration engines allow biogas to be used directly in its existing state and, second, the infrastructure needed for the injection of purified biogas (biomethane) into the fossil natural gas network is not available near their production sites.

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14      Similarly, the definitions in Regulation (EU) 2019/943 of the European Parliament and of the Council of 5 June 2019 on the internal market for electricity (OJ 2019 L 158, p. 54) and in Directive (EU) 2019/944 of the European Parliament and of the Council of 5 June 2019 on common rules for the internal market for electricity and amending Directive 2012/27/EU (OJ 2019 L 158, p. 125) are also applicable for the purposes of Regulation 2022/1854.

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15      Judgment of 1 August 2025, Alace and Canpelli (C‑758/24 and C‑759/24, EU:C:2025:591, paragraph 91 and the case-law cited).

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16      Article 2(24) of Directive 2018/2001 defines ‘biomass’ as ‘the biodegradable fraction of products, waste and residues [of] biological origin from agriculture, including vegetal and animal substances, from forestry and related industries, including fisheries and aquaculture, as well as the biodegradable fraction of waste, including industrial and municipal waste of biological origin’. That definition largely reproduces the definition in Article 2(b) of Directive 2001/77/EC of the European Parliament and of the Council of 27 September 2001 on the promotion of electricity produced from renewable energy sources in the internal electricity market (OJ 2001 L 283, p. 33).

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17      Accordingly, it would seem that the EU legislature considered ‘biogas’ to be a generic notion covering any gaseous biomass fuel.

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18      Directive (EU) 2024/1788 of the European Parliament and of the Council of 1 June 2024 on common rules for the internal markets for renewable gas, natural gas and hydrogen, amending Directive (EU) 2023/1791 and repealing Directive 2009/73/EC (OJ L, 2024/1788) now defines, in Article 2(1), ‘natural gas’ as ‘gas that primarily consists of methane, including biomethane, … that can technically and safely be injected into, and transported through, the natural gas system’ and, in Article 2(2), ‘renewable gas’ as ‘biogas as defined in Article 2, point (28), of Directive [2018/2001], including biogas that has been upgraded to biomethane, and renewable fuels of non-biological origin as defined in Article 2, point (36), of that Directive’. It is clear from those definitions that the EU legislature considers the notion of ‘natural gas’ to include biomethane. Furthermore, those definitions also show that biogas may be ‘upgraded to biomethane’. That upgrading depends on an additional purification and compression process.

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19      See, in that connection, recital 33 of Regulation 2022/1854.

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20      I further note that the proposal for Regulation 2022/1854 follows similar lines, stating that ‘the cap should not apply to power plants using biomethane. This is necessary in order to preserve the incentives for these technologies and generation types to decrease gas consumption, as highlighted in [the REPowerEU plan]’. See, in particular, p. 10 of that plan.

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21      That upgrading method is characterised by the local and immediate use of biogas, generally through cogeneration facilities, as in the present case.

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22      See judgment of 12 July 2018, Spika and Others (C‑540/16, EU:C:2018:565, paragraph 35 and the case-law cited).

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23      See judgment of 29 July 2024, Belgian Association of Tax Lawyers and Others (C‑623/22, EU:C:2024:639, paragraph 24 and the case-law cited).

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24      See judgment of 29 July 2024, Belgian Association of Tax Lawyers and Others (C‑623/22, EU:C:2024:639, paragraph 25 and the case-law cited).

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25      See judgment of 29 July 2024, Belgian Association of Tax Lawyers and Others (C‑623/22, EU:C:2024:639, paragraph 26 and the case-law cited).

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26      As observed in point 50 of this Opinion, the cap does not apply to natural gas or to technologies based on fuels capable of being a substitute for natural gas, such as biomethane.

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27      Furthermore, there is nothing in the order for reference to suggest that the EU legislature’s choice to distinguish the two technologies in question was manifestly erroneous.

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28      Like the first two questions referred, this third question has its basis in the specific situation of Rouge Lux and Biospace, whose electricity generation activity is ancillary to their main activity in the agricultural sector. According to the order for reference, the facility of one of them exceeds the threshold of 1 MW of maximum installed capacity only marginally, as its total installed capacity is 1.004 MW. According to those parties, the fact that Member States are unable to provide for a progressive levy rate depending on the installed capacity of facilities subject to the cap constitutes an infringement of Articles 20 and 21 of the Charter. They submit in that regard that producers in virtually identical situations are nevertheless accorded different treatment, depending on whether their facility has an installed capacity slightly below or slightly above that threshold.

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29      See, to that effect, judgment of 24 March 2011, Commission v Spain (C‑400/08, EU:C:2011:172, paragraph 124 and the case-law cited).

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30      See, by analogy, recital 37 of Regulation 2022/1854 and the judgment in Electrabel and Others (paragraph 42).

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31      I note, in so far as it is relevant, that the Explanatory memorandum for the proposal which led to the adoption of Regulation 2022/1854 refers both to the objective of avoiding an excessive administrative burden and to the objective of ensuring an efficient application of the proposed measure. See, in that regard, Proposal for a Council Regulation on an emergency intervention to address high energy prices (COM(2022) 473 final).

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32      See, to that effect, judgment of 16 December 2008, Arcelor Atlantique and Lorraine and Others (C‑127/07, EU:C:2008:728, paragraph 57 and the case-law cited).

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33      As far as the exercise of the discretion enjoyed by the EU legislature is concerned, it is clear from the Court’s case-law, as I noted in point 53 of this Opinion, that the principle of equal treatment can be considered to have been infringed only if the institution concerned made an arbitrary or manifestly inappropriate differentiation having regard to the objective pursued by the rules in question. That is clearly not the case here. I note in that regard that there is nothing in the order for reference to call into question the reasonableness of the threshold adopted or to demonstrate that the EU legislature exceeded the limits of its discretion in this case. Furthermore, given the extent of that discretion, setting a threshold of 1 MW cannot be considered unreasonable, less still manifestly unreasonable, solely because other measures could also have been envisaged.

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34      See judgment of 10 July 2025, INTERZERO and Others (C‑254/23, EU:C:2025:569, paragraph 145 and the case-law cited).

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35      See, to that effect, judgments of 15 April 2021, Federazione nazionale delle imprese elettrotecniche ed elettroniche (Anie) and Others (C‑798/18 and C‑799/18, EU:C:2021:280, paragraphs 35 and 36), and of 5 September 2024, Novo Banco and Others (C‑498/22 to C‑500/22, EU:C:2024:686, paragraph 112).

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36      See judgment of 3 September 2015, Inuit Tapiriit Kanatami and Others v Commission (C‑398/13 P, EU:C:2015:535, paragraph 61).

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37      I note in that regard that electricity prices on the EU market are determined according to a marginal pricing mechanism under which facilities are dispatched in ascending order of production costs: power plants with the lowest marginal costs are mobilised first, while all producers are paid the price set by the last power plant needed to satisfy the demand. See also, in that regard, recitals 23 and 24 of Regulation 2022/1854.

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38      See, judgment of 10 September 2024, Neves 77 Solutions (C‑351/22, EU:C:2024:723, paragraph 85 and the case-law cited).

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39      See, inter alia, ECtHR, 29 April 2008, Burden v. United Kingdom, CE:ECHR:2008:0429JUD001337805, § 59.

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40      See, inter alia, ECtHR, 22 January 2009, ‘Bulves’ AD v. Bulgaria, CE:ECHR:2009:0122JUD000399103, § 62.

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41      See, inter alia, ECtHR, 3 July 2003, Buffalo Srl in liquidation v. Italy, CE:ECHR:2003:0703JUD003874697, § 32. See also judgment of 10 July 2025, INTERZERO and Others (C‑254/23, EU:C:2025:569, paragraph 153).

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42      See point 111 of this Opinion.

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43      See recitals 28 and 29 of Regulation 2022/1854.

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44      According to recital 28 of Regulation 2022/1854, that cap was set at a level above both reasonable market expectations and the prices which could normally be expected in the absence of the exceptional circumstances in question, since wholesale electricity prices had not, on average, exceeded EUR 80/MWh over the preceding years.

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45      See judgment of 22 January 2013, Sky Österreich (C‑283/11, EU:C:2013:28, paragraph 50 and the case-law cited).

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46      See, by analogy, judgment of 13 June 2017, Florescu and Others (C‑258/14, EU:C:2017:448, paragraph 55).

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47      See, to that effect, recital 41 of Regulation 2022/1854, which states that ‘Member States should retain the possibility to further limit the revenues of the producers to which the cap on market revenues applies’. It should also be noted that at least 17 Member States adopted a cap below EUR 180/MWh, as is clear from the Report from the Commission to the European Parliament and the Council on the review of emergency interventions to address high energy prices in accordance with Regulation 2022/1854 of 5 June 2023 (COM(2023) 302 final).

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48      See the judgment in Secab (paragraphs 42 and 68).

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49      See the judgment in Electrabel and Others (paragraphs 29 and 30).

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50      I note that that recital states that, given that the generation mix and the cost-structure of power-generating facilities differ greatly among Member States, they should be allowed to maintain or introduce national crisis measures under specific conditions.

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51      Moreover, recital 41 of Regulation 2022/1854, which refers to the possibility for Member States to further limit the revenues of the producers to which the cap on market revenues applies, makes no reference to ‘specific conditions’.

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52      See, in that regard, judgment of 2 June 2022, Skeyes (C‑353/20, EU:C:2022:423, paragraph 60 and the case-law cited).

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53      It is apparent from the order for reference and from the written observations of the Belgian Government that, according to the Council of Ministers, the chosen reference price of EUR 130/MWh is based, first, on the maximum electricity price that could be expected before the COVID-19 and energy crises, namely EUR 80/MWh, and, second, on a margin of EUR 50/MWh to cover the commercial risks and accrued losses of electricity producers, taking into account, inter alia, inflation and increased electricity supply costs.

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54      The referring court will thus have to determine whether, by setting the cap at that level, the Belgian authorities had regard not only to the average prices observed in the past, but also to peak prices. Recital 28 of Regulation 2022/1854 makes clear in that regard that the cap on revenues should not be based on average prices, but should leave a margin and be set at a level reflecting the peak price, since investors also take account of revenues generated during periods of high prices. Furthermore, in order to assess the potential impact of that cap on investments in renewable energies, recital 29 of that regulation specifies that reference should be made to the LCOE for the relevant technology, which measures the net costs of electricity generation borne by a producer over the entire lifetime of a facility.

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55      The Austrian Government challenges the admissibility of that sixth question in so far as it concerns the principle of energy solidarity, on the ground that the referring court does not explain why it considers that Article 6(1) and Article 8 of Regulation 2022/1854 could infringe that principle. However, in view of the presumption of relevance enjoyed by questions referred for a preliminary ruling and the information provided by that court, in particular its queries whether the EU legislature struck an appropriate balance between the interests of the European Union and the interests of the different Member States, I consider that the objection should be rejected.

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56      It is clear that that obligation also requires the Member States to respect the fundamental rights and general principles enshrined in EU law. In that regard, according to the Court’s settled case-law, the fundamental rights guaranteed in the legal order of the European Union are applicable in all situations governed by EU law (see judgment of 19 November 2019, TSN and AKT, C‑609/17 and C‑610/17, EU:C:2019:981, paragraph 43 and the case-law cited).

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57      See, to that effect, judgments of 10 July 2025, INTERZERO and Others (C‑254/23, EU:C:2025:569, paragraph 140 and the case-law cited), and of 13 November 2025, PB Vi Goods (C‑563/24, EU:C:2025:887, paragraph 27 and the case-law cited).

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58      See, to that effect, judgments of 10 July 2025, INTERZERO and Others (C‑254/23, EU:C:2025:569, paragraph 141 and the case-law cited).

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59      See, in that connection, point 87 of this Opinion.

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60      The answer to that question requires transposing the analysis on a limitation of the right to property which is the subject of the fourth question. See, in that regard, points 69 to 75 of this Opinion.

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61      See the judgment in Germany v Poland (paragraphs 38 and 41 and the case-law cited).

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62      See, to that effect, judgments in Germany v Poland (paragraphs 38 and 41 and the case-law cited), and of 26 September 2024, Orlen v Commission (C‑255/22 P, EU:C:2024:790, paragraph 91).

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63      See, to that effect, judgments in Germany v Poland (paragraphs 44 and 45), and of 26 September 2024, Orlen v Commission (C‑255/22 P, EU:C:2024:790, paragraph 92). See also my Opinion in Orlen v Commission (C‑255/22 P, EU:C:2024:466, points 48 and 49).

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64      See the judgment in Germany v Poland (paragraphs 53 and 69).

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65      See the judgment in Germany v Poland (paragraph 73).

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66      Under that provision, ‘without prejudice to any other procedures provided for in the Treaties, the Council, on a proposal from the Commission, may decide, in a spirit of solidarity between Member States, upon the measures appropriate to the economic situation, in particular if severe difficulties arise in the supply of certain products, notably in the area of energy.’ My italics.

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67      See recital 9 of Regulation 2022/1854.

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68      See also points 50 and 51 of this Opinion.

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69      See recitals 6 and 46 of Regulation 2022/1854.

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70      See judgment of 10 July 2025, Ligue royale belge pour la protection des oiseaux (C‑287/24, EU:C:2025:550, paragraph 24 and the case-law cited).

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71      See, to that effect, judgment of 22 November 2018, Swedish Match (C‑151/17, EU:C:2018:938, paragraphs 78 and 79 and the case-law cited).

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72      See, to that effect, judgment of 26 March 2026, Pumpyanskiy and Others v Council (C‑696/23 P, C‑704/23 P, C‑711/23 P, C‑35/24 P and C‑111/24 P, EU:C:2026:245, paragraph 188 and the case-law cited).

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73      See, to that effect, judgment of 4 October 2024, Lithuania and Others v Parliament and Council (Mobility package) (C‑541/20 to C‑555/20, EU:C:2024:818, paragraphs 158, 159 and 162 and the case-law cited).

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74      See, to that effect, judgment of 4 October 2024, Lithuania and Others v Parliament and Council (Mobility package) (C‑541/20 to C‑555/20, EU:C:2024:818, paragraphs 616 and 617 and the case-law cited).

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75      That includes inter alia the level of the cap and the technologies to which it applies.

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76      Furthermore, the fact that the EU legislature applied a common criterion in making that categorisation, without specifying its application to each relevant technology, cannot undermine the principle of legal certainty.

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77      I would also point out that the cap introduced by Regulation 2022/1854 applies to ‘surplus revenues’, which correspond to extraordinary profits that the companies concerned could not have expected in the absence of unforeseeable circumstances affecting the energy markets. See, to that effect, my Opinion in Secab (C‑423/23, EU:C:2025:63, points 52 and 53).

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78      See point 12 of this Opinion.

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79      Moreover, where the determination of numeric thresholds arises in the framework set by the legislature, it does not require specific reasons to be given. Any such threshold is, in fact, liable to be replaced by a more favourable threshold, without that circumstance alone giving rise to a specific obligation to give reasons. See, in that connection, point 61 of this Opinion.

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80      More precisely, as regards the criteria which can be taken into consideration by the referring court in that analysis, I refer to point 87 of this Opinion.

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81      The ninth question referred for a preliminary ruling in the present case, which also concerns the use of presumptions by the Belgian Government, corresponds to the first question referred for a preliminary ruling in the case giving rise to the judgment in Electrabel and Others.

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82      See the judgment in Electrabel and Others (paragraph 48).

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83      See the judgment in Electrabel and Others (paragraph 53).

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84      See the judgment in Electrabel and Others (paragraphs 51 to 55).

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85      See points 52 and 53 of this Opinion.

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86      In any event, and in view of the considerable discretion enjoyed by Member States in this case, only a manifest error of assessment could be sanctioned, as was noted in point 53 of this Opinion. None of the information available to the Court suggests that there is any such error.

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87      The wording of the third question referred for a preliminary ruling by the cour d’appel de Bruxelles in that case was almost identical. That case concerned the same provision of national law governing the temporal scope of the Law of 16 December 2022, namely Article 22b thereof.

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88      See the judgment in Electrabel and Others (paragraphs 57 to 65).

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89      See the judgment in Electrabel and Others (paragraph 58).

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90      See the judgment in Electrabel and Others (paragraph 64).

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91      See judgment of 8 June 2023, UFC – Que choisir and CLCV (C‑407/21, EU:C:2023:449, paragraph 78 and the case-law cited).

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92      See judgment of 8 June 2023, UFC – Que choisir and CLCV (C‑407/21, EU:C:2023:449, paragraph 79 and the case-law cited).

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93      See judgment of 12 September 2024, Chaudfontaine Loisirs (C‑73/23, EU:C:2024:734, paragraph 54 and the case-law cited).

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94      See judgments of 22 June 2021, Latvijas Republikas Saeima (Penalty points) (C‑439/19, EU:C:2021:504, paragraph 135 and the case-law cited).

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95      See judgment of 12 September 2024, Chaudfontaine Loisirs (C‑73/23, EU:C:2024:734, paragraph 60 and the case-law cited).

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96      See, to that effect, judgment of 29 July 2019, Inter-Environnement Wallonie and Bond Beter Leefmilieu Vlaanderen (C‑411/17, EU:C:2019:622, paragraphs 178 to 180). That case concerned the lawfulness of measures adopted in breach of the obligation under EU law to carry out a prior assessment of the effects of a project on the environment. In the judgment, the Court confirmed the power of national courts to adjust the effects of annulment of a national provision held to be incompatible with EU law for overriding considerations relating to the protection of the environment. It made clear, however, that where such considerations relate to the security of the supply, the annulment or suspension of the effects of the contested national measures is subject to the existence of a genuine and serious threat of disruption to the electricity supply which could not be remedied by any other means or alternatives. See also judgments of 25 June 2020, A and Others (Wind turbines at Aalter and Nevele) (C‑24/19, EU:C:2020:503, paragraphs 92 and 94 and the case-law cited), and of 6 October 2020, La Quadrature du Net and Others (C‑511/18, C‑512/18 and C‑520/18, EU:C:2020:791, paragraph 218).

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97      See, to that effect, judgment of 29 July 2019, Inter-Environnement Wallonie and Bond Beter Leefmilieu Vlaanderen (C‑411/17, EU:C:2019:622, paragraphs 178 and 179 and the case-law cited), and of 8 June 2023, UFC – Que choisir and CLCV (C‑407/21, EU:C:2023:449, paragraph 82 and the case-law cited).

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98      The revenues collected from the levy in question have already been allocated to finance various measures adopted in response to the energy crisis and the annulment ex tunc of the contested law would therefore entail their repayment, resulting in a major legal dispute and significant tax losses for the Kingdom of Belgium. In its written observations, the Belgian Government asserts in that regard that those losses could exceed EUR 1 billion, representing 0.2% of its GDP.

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99      See judgment of 5 October 2023, Osteopathie Van Hauwermeiren (C‑355/22, EU:C:2023:737, paragraph 37 and the case-law cited).

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100      See judgment of 14 April 2015, Manea (C‑76/14, EU:C:2015:216, paragraph 55 and the case-law cited). See also Opinions of Advocate General Mengozzi in Tjebbes and Others (C‑221/17, EU:C:2018:572, points 53 and 54 and the case-law cited), and of Advocate General Medina in UFC – Que choisir and CLCV (C‑407/21, EU:C:2022:690, point 102 and the case-law cited). I would point out, for the sake of completeness, that, according to the Court’s settled case-law, a risk of serious economic repercussions can be recognised only if there were a large number of legal relationships entered into in good faith on the basis of rules considered to be validly in force and if it appeared that individuals and national authorities had been led to adopt practices which did not comply with EU law by reason of objective, significant uncertainty regarding the implications of EU provisions, to which the conduct of other Member States or the Commission may even have contributed. See, in that regard, judgment of 28 October 2020, Bundesrepublik Deutschland (Determination of toll rates for the use of motorways) (C‑321/19, EU:C:2020:866, paragraph 56 and the case-law cited).

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101      It is true that the Law of 16 December 2022 was adopted pursuant to Regulation 2022/1854 in an exceptional context characterised by an unprecedented emergency. In that regard, a number of factors must be taken into consideration, such as the broad discretion accorded to Member States in implementing that regulation, including the option to adopt measures which are more or less strict than those expressly provided for therein, and the absence of specific guidance from the Commission, notwithstanding the provisions of the regulation to that effect. Furthermore, the legitimate objectives pursued by the regulation, including the protection of consumers, are of particular importance. Those factors allow the action of the national legislature to be placed in context and may justify some flexibility in the assessment of the measures adopted by Member States. However, they cannot, in themselves, justify a relaxation of the requirements under EU law or be interpreted as conferring on Member States any immunity vis-à-vis them. I wish to point out that the Court’s case-law concerning the possibility for national courts to adjust the effects of annulment of a national provision held to be incompatible with EU law is strictly exceptional in nature. As is evident from the Court’s case-law cited in point 144 of this Opinion, the mere existence of a crisis context, however exceptional, cannot in itself justify a derogation from that principle.

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102      See, by analogy, judgment of 6 October 2020, La Quadrature du Net and Others (C‑511/18, C‑512/18 and C‑520/18, EU:C:2020:791, paragraph 219), in which the Court ruled that the consequence of maintaining the effects of the national legislation at issue would be to continue to impose on providers of electronic communications services obligations which are contrary to EU law and which seriously interfere with the fundamental rights of the persons whose data has been retained.