1.

Are Article 6(1) and Article 7(1) of Directive 93/13/EEC (1) to be interpreted as precluding national legislation or judicial practice based on national legislation under which, in the case of long-term energy supply contracts in respect of which the customer has not challenged price increases for an extended period of time and is now claiming that price increases dating back a long time are also ineffective, the regulatory gap created by an ineffective price adjustment clause or ineffective incorporation of a price adjustment clause is normally filled by means of supplementary contract interpretation to the effect that the customer cannot rely on the ineffectiveness of price increases leading to a price higher than the initial price agreed if the customer has not challenged these in the first three years after receipt of the respective annual bills in which the price increase was applied for the first time?

2.

Are Article 6(1) and Article 7(1) of Directive 93/13/EEC to be interpreted as precluding national legislation or judicial practice based on national legislation, under which long-term energy supply contracts, in respect of which the customer has not challenged price increases arising from an ineffective price adjustment clause or ineffective incorporation of a price adjustment clause in the contract for an extended period of time and is now claiming that price increases dating back a long time are also ineffective, are to be regarded as ineffective?

3.

Are Article 6(1) and Article 7(1) of Directive 93/13/EEC to be interpreted as precluding national legislation or judicial practice based on national legislation, under which a district heating supplier has the right and – in so far as the interests of the customer so require – an obligation to unilaterally amend a price adjustment clause applied by the district heating supplier vis-à-vis end customers – which has been ineffective since the start of the contract or has been ineffective since a particular point in time thereafter – including during the ongoing supply relationship with effect for the future, if and to the extent that this ensures the clause is then effective?