Article 107(1) TFEU must be interpreted as meaning that a national measure, such as that at issue in the main proceedings, placing an obligation on both private and public undertakings to purchase electricity produced by cogeneration with the production of heat does not constitute intervention by the State or through State resources.

It is thus apparent from the information before the Court that, in certain circumstances, electricity suppliers purchased electricity produced by cogeneration at a higher price than that charged to end users, which resulted in extra costs for the suppliers.

Consequently, given that those extra costs cannot be passed on entirely to end users and are not financed by a compulsory contribution imposed by the State or by a full offset mechanism (see, to that effect, judgments of 17 July 2008, Essent Netwerk Noord and Others, C‑206/06, EU:C:2008:413, and of 19 December 2013, Association Vent De Colère! and Others, C‑262/12, EU:C:2013:851), it must be concluded, as the Advocate General observed in point 86 of his Opinion, that the supply undertakings were not appointed by the State to manage a State resource, but were funding a purchase obligation imposed on them by having recourse to their own financial resources.

As regards the argument put forward by ENEA and the Commission that most of the undertakings bound by the purchase obligation were public undertakings governed by private law and therefore that obligation could be regarded as being financed through State resources, it should be noted that the resources of public undertakings may be regarded as State resources where the State is capable, by exercising its dominant influence over such undertakings, of directing the use of their resources in order to finance advantages to the benefit of other undertakings (see, to that effect, judgment of 16 May 2002, France v Commission, C‑482/99, EU:C:2002:294, paragraph 38).

As the Advocate General noted in points 91, 94 to 96 and 100 of his Opinion, the mere fact that the State held the majority of the capital in some of the undertakings subject to the purchase obligation does not lead to the conclusion that, in the main proceedings, the State exercised a dominant influence that enabled it to direct the use of the resources of those undertakings within the meaning of the case-law referred to in the preceding paragraph.

It appears that the purchase obligation applied equally to all electricity suppliers, regardless of whether their capital was predominantly held by the State or by private operators.

Moreover, contrary to the Commission’s submissions, the fact that the measure is attributable to the Member State concerned, as established in paragraph 22 above, does not mean that it may be inferred that that Member State exercises a dominant influence over an undertaking in which it is the majority shareholder, within the meaning of the judgment of 16 May 2002, France v Commission (C‑482/99, EU:C:2002:294, paragraphs 38 and 39). There is nothing in the State’s conduct as legislator to suggest that it exercised such influence in its capacity as majority shareholder in an undertaking.

(see paras 29-33, 35, 37, operative part)