Opinion of Advocate General Rantos delivered on 17 November 2022

A. European Union law

B. German law

11. Paragraph 3, headed ‘Definitions’, of the Erneuerbare-Energien-Gesetz (German law on renewable energy; ‘the EEG’) of 25 October 2008, in the version in force between 1 January 2012 and 31 July 2014 (‘the 2012 EEG’),⁽⁷⁾ states:

‘For the purposes of the present law:

1. “installation” means any facility for producing electricity from renewable energy sources …;

…

1. “Renewable energy” … means energy from biomass … and from the biodegradable fraction of industrial and municipal waste;

…’

12. Paragraph 8 of that law, headed ‘Purchase, transmission and distribution’, provides, in subparagraph 1:

‘Subject to Paragraph 11, system operators shall be obliged to purchase, transmit and distribute, on a priority basis without undue delay, all electricity from renewable energy sources which is offered. …’

13. Paragraph 11 of that law, headed ‘Feed-in management’, provides, in subparagraph 1:

‘… system operators shall be entitled, by way of exception, to regulate installations … directly or indirectly connected to their systems, in so far as …:

1. failure to do so would give rise to system congestion in the relevant part of the system, including the upstream system;

2. priority is given to electricity from renewable energy sources, … unless other installations for producing electricity must remain connected to the grid in order to ensure the security and reliability of the electricity supply system …;

…’

14. Paragraph 12 of that law, headed ‘Special provisions’, provides in subparagraph 1:

‘If the feed-in of electricity from installations for producing electricity from renewable energy sources … is curtailed due to system congestion within the meaning of Paragraph 11(1), the operators affected by the measure shall be compensated … for 95% of the lost revenue plus any additional expenses incurred and less any expenses saved. …’

15. Paragraph 16 of the 2012 EEG, headed ‘Entitlement to remuneration’, states in subparagraph 1:

‘System operators shall remunerate installation operators for electricity from installations using only renewable energy sources … in accordance with, as a minimum, Paragraphs 18 to 33. …’

16. Those provisions of the 2012 EEG correspond, in essence, to those of the EEG in the version in force between 1 January 2009 and 31 December 2011⁽⁸⁾ and those of the EEG in the version in force between 1 August 2014 and 31 December 2016.⁽⁹⁾

A. The first question referred

30. By its first question, the referring court asks, in essence, whether Article 16(2)(c) of Directive 2009/28 must be interpreted as meaning that priority access to the electricity grid enjoyed by electricity generating installations using renewable energy sources must be granted not only to installations producing electricity exclusively from renewable energy sources, but also to installations producing electricity by thermal recovery from mixed waste containing a proportion of industrial and municipal biodegradable waste.

31. Article 16(2)(c) of Directive 2009/28 provides that Member States are to ensure that, when dispatching electricity generating installations, transmission system operators give priority to generating installations using renewable energy sources in so far as the secure operation of the national electricity system so permits and based on transparent and non-discriminatory criteria.

32. I note that that provision reflects the fact that, from a technical point of view, electricity transmission and distribution systems have an intrinsically limited delivery capacity and cannot necessarily deliver all the electricity produced or capable of being produced by the installations connected to them, taking account of consumption.⁽¹¹⁾ In those circumstances, the EU legislature chose to give preference to electricity generating installations using renewable energy sources. In that regard, as the Court has held, although Article 32(2) of Directive 2009/72/EC⁽¹²⁾ provides that the operator of a distribution system may refuse access where it lacks the necessary capacity, on condition that duly substantiated reasons are given for such refusal, that possibility of refusing access to the system is to be assessed on a case-by-case basis and does not authorise the Member States to lay down those derogations in a general manner without, in respect of each operator, a concrete assessment of the technical incapacity of the system to meet the demand for access from third parties.⁽¹³⁾

33. In the light of the first question referred, it is necessary to ascertain what is meant by the term ‘electricity generating installation using renewable energy sources’, referred to in Article 16(2)(c) of Directive 2009/28, in order to determine whether that concept covers an installation producing electricity by thermal recovery from mixed waste containing a proportion of industrial and municipal biodegradable waste. If so, that installation must be granted priority access to the electricity grid as laid down in that provision and, if the distribution system operator refuses such access, it would then qualify for financial compensation, as recital 61 of that directive makes clear.

34. Directive 2009/28 does not define the concept of ‘electricity generating installation using renewable energy sources’. According to the settled case-law of the Court, it follows from the need for uniform application of EU law and from the principle of equality that the terms of a provision of EU law which makes no express reference to the law of the Member States for the purpose of determining its meaning and scope must normally be given an autonomous and uniform interpretation throughout the European Union; that interpretation must take into account not only its wording but also its context and the objective pursued by the legislation in question.⁽¹⁴⁾

35. Against that background, it should be noted, in the first place, that the wording of Article 16(2)(c) of Directive 2009/28, which refers only to installations using renewable energy sources, does not in itself make it possible to determine whether that provision covers installations producing electricity by thermal recovery from mixed waste containing a proportion of industrial and municipal biodegradable waste.

36. In the second place, regarding the context of which that provision forms part, as the referring court pointed out, Article 2(c) of Directive 2001/77 defined ‘electricity produced from renewable energy sources’ as ‘electricity produced by plants using only renewable energy sources, as well as the proportion of electricity produced from renewable energy sources in hybrid plants also using conventional energy sources’.⁽¹⁵⁾ However, that directive was no longer in force at the time of the facts in the main proceedings. Article 2(a) of Directive 2009/28, for its part, defines ‘energy from renewable sources’ as ‘energy from renewable non-fossil sources, namely wind, solar, aerothermal, geothermal, hydrothermal and ocean energy, hydropower, biomass, landfill gas, sewage treatment plant gas and biogases’. Consequently, as 50 Hertz stated in its written observations, in the dispute in the main proceedings, the classification of electricity as ‘renewable electricity’ no longer depends, therefore, on the installation in which the electricity was produced, but only on the energy sources used.

37. Article 2(a) of Directive 2009/28 states that biomass energy⁽¹⁶⁾ is to be regarded as energy obtained from renewable sources. According to the definition in Article 2(e) of that directive, biomass includes the ‘biodegradable fraction of industrial and municipal waste’. It follows from those provisions, read together, that energy produced by thermal recovery from mixed waste containing a proportion of industrial and municipal biodegradable waste must be regarded, for that proportion, as energy from renewable sources.

38. In the present case, it follows from the order for reference that the installation at issue treats mixed waste containing proportions of municipal and industrial biodegradable waste, which thus constitutes biomass within the meaning of Article 2(e) of that directive.⁽¹⁷⁾

39. Furthermore, Article 5(3) of Directive 2009/28 states that, in multi-fuel plants using renewable and conventional sources, only the part of electricity produced from renewable energy sources is to be taken into account. Consequently, that directive does not exclude from its scope, as a matter of principle, installations which partly use renewable energy sources.

40. In the third place, concerning the objectives pursued by Directive 2009/28, the purpose of that directive, as is apparent from Article 1 thereof, is to lay down a common framework for the promotion of energy from renewable sources by setting, inter alia, mandatory national targets for the overall share of energy from renewable sources in gross final consumption of energy.⁽¹⁸⁾ To that effect, Article 16(2)(c) of that directive provides that Member States are to ensure that appropriate grid and market-related operational measures are taken in order to minimise the curtailment of electricity produced from renewable energy sources. Moreover, recital 60 of Directive 2009/28 states that, in the event that the electricity from renewable energy sources is integrated into the spot market, guaranteed access ensures that all electricity sold and supported obtains access to the grid, allowing the use of a maximum amount of electricity from renewable energy sources from installations connected to the grid. Recital 61 makes clear that the objectives of the directive require a sustained increase in the transmission and distribution of electricity produced from renewable energy sources without affecting the reliability or safety of the grid system.

41. In addition, I note that, according to the Court’s case-law, the purpose of guaranteed access to the grid system provided for in Article 16(2)(b) of Directive 2009/28 is to integrate renewable energy sources into the internal market for electricity by ensuring that all electricity produced from renewable energy sources has access to the grids, allowing the use of a maximum amount of electricity produced from renewable energy sources.⁽¹⁹⁾

42. Consequently, the aim of Directive 2009/28 is to achieve the widest possible use of renewable energy sources. Not granting priority to installations producing electricity by thermal recovery from mixed waste containing a proportion of biodegradable waste would result in that proportion of renewable energy sources being lost if the distribution system operator were to refuse to give the electricity producer concerned access to its system due to congestion.

43. I therefore propose that the following answer be given to the first question referred for a preliminary ruling: Article 16(2)(c) of Directive 2009/28 is to be interpreted as meaning that priority access to the electricity grid enjoyed by electricity generating installations using renewable energy sources must be granted not only to installations producing electricity exclusively from renewable energy sources, but also to installations producing electricity by thermal recovery from mixed waste containing a proportion of industrial and municipal biodegradable waste.

B. The second to fifth questions referred for a preliminary ruling

44. By the second to fifth questions, which should be examined together, the referring court asks, in essence, whether Article 16(2)(c) of Directive 2009/28 must be interpreted as meaning that an electricity generating installation enjoys priority access to the electricity grid only for electricity produced from the biodegradable fraction of the industrial and municipal waste used and, if so, what are the detailed rules for applying that priority access.

45. As explained in the answer given to the first question, it follows from Article 2(a) and (e) of Directive 2009/28 that energy obtained from biomass is energy from renewable sources but, as regards industrial and municipal waste, only the biodegradable fraction of such waste is taken into account. It follows that an electricity generating installation enjoys priority access to the electricity grid, on the basis of Article 16(2)(c) of that directive, solely for electricity produced from that biodegradable fraction and not from the fraction made up of conventional waste.

46. In the same vein, the Court has found, in connection with Article 16(2)(b) of that directive, that although that provision refers to the possibility of establishing ‘guaranteed access’ to the grid for electricity produced from renewable energy sources, that possibility applies only to ‘green’ electricity and that provision cannot therefore serve as a legal basis for national provisions on guaranteed access for installations producing energy from a non-renewable energy source.⁽²⁰⁾ That interpretation may apply by analogy to priority access to the grid referred to in Article 16(2)(c) of that directive.

47. According to its wording, that provision establishes such priority access for installations producing electricity from renewable energy sources, but does not, where those installations use renewable and conventional energy sources simultaneously, require the renewable energy source to attain a minimum share. In other words, priority for the feeding of electricity into the grid laid down in that provision does not depend on whether the proportion of biodegradable waste used for the production of electricity is large or small, since the share of conventional waste does not affect that priority. Accordingly, there is no threshold below which electricity produced from renewable energy sources does not qualify for priority access to the grid.⁽²¹⁾

48. In so far as an electricity generating installation enjoys priority access to the grid solely for electricity produced from that biodegradable fraction, the referring court asks how that priority access should be applied, by reference to the second subparagraph of Article 5(3) of Directive 2009/28.

49. In that regard, I note that, from a legal point of view, it follows from the Court’s case-law that, far from seeking to bring about exhaustive harmonisation of national support schemes for green energy production, the EU legislature based its approach on the finding that Member States apply different support schemes and on the principle that it is important to ensure the proper functioning of those schemes in order to maintain investor confidence and to enable those States to define effective national measures in order to achieve their mandatory national overall targets under that directive.⁽²²⁾ In my view, the same reasoning may be applied in connection with the implementation of Article 16(2)(c) of Directive 2009/28. Therefore, it must be found that Member States have significant freedom of action when applying priority access to the electricity grid to installations using renewable energy sources.

50. Furthermore, from a technical point of view, MNG Strom explained that the electricity transmission system operator does not know, in real time, what proportion of biodegradable waste is being used by an electricity generating installation when that operator has to decide on the order in which installations are to be shut down; indeed, the operators of those installations do not know what proportion of energy is being produced from renewable sources at any given time. For its part, 50 Hertz stated that the decision on priority is an emergency measure taken in virtually a split second and that it has repercussions for downstream operators, as a result of which priority criteria must make it possible for the system operator to be given specific guidance. In addition, the Commission submitted that, in some cases, it may be technically impossible to apply priority access to the grid to only part of the electricity produced by an installation, in this case the part obtained from renewable energy sources.

51. Against that legal and technical backdrop, I take the view that it is not for the Court to set out in detail how priority access to the electricity grid should be applied, since that is the task, in accordance with the wording of Article 16(2)(c) of Directive 2009/28, of the Member States, which are the best acquainted with the specific nature of the national electricity transmission system.⁽²³⁾ At the hearing, MNG Strom thus pointed to the existence of guidelines in Germany on the management of the electricity transmission system, which, having as their objective the reliability and security of that system, have established the order in which installations are to be disconnected in order to reduce physical congestion in that system.

52. Nevertheless, and having regard to the written observations of the interested parties and the submissions made during the hearing, the Court still has jurisdiction to provide guidance, based on the provisions of Directive 2009/28, on the factors to be taken into account by Member States for the purpose of applying priority access to the electricity grid.

53. In that regard, first, it follows from the wording of Article 16(2)(c) of that directive that priority access must be implemented in so far as the secure operation of the national electricity system so permits. In that connection, as stated in recital 60 of that directive, requirements relating to the maintenance of the reliability and safety of the grid and to the dispatching may differ according to the characteristics of the national grid and its secure operation.

54. Second, it is also apparent from Article 16(2)(c) of that directive that priority access to the electricity grid must be granted on the basis of transparent and non-discriminatory criteria, which requires that those criteria be clear, that they be notified in advance by the Member States and that their application be foreseeable for all the parties concerned.

55. Third, it follows from the objectives of Directive 2009/28 that Member States must give installations which exclusively produce energy from renewable sources access to the electricity grid as a matter of maximum priority, so that any refusal to grant them access to the grid must be a last resort.

56. Fourth, in the case of installations producing electricity by treating mixed waste containing a proportion of biodegradable waste, my view is that those installations must be taken into account where that proportion is stable over time, quantifiable and significant. Otherwise, there is a risk of abuse, particularly if it is technically impossible to apply priority access to the grid to only part of the electricity produced by an installation and the installation enjoys such priority even though, in practice, the electricity is mainly produced from conventional energy sources. That would be the case, for example, if the share of energy produced from renewable sources were to vary depending on the period concerned, with the result that, for some periods, that share was negligible or nil.

57. Fifth, EEW submits that, during the period at issue in the main proceedings, it consistently received from the Umweltbundesamt (Federal Office for the Environment, Germany) the guarantees of origin referred to in Article 15 of Directive 2009/28, which enabled it to prove that approximately 50% of its electricity output came from renewable energy sources. However, as is apparent from Article 2(j) of that directive, ‘guarantee of origin’ is defined as an electronic document which has the sole function of providing proof to a final customer that a given share or quantity of energy was produced from renewable sources. Consequently, that guarantee is drawn up retrospectively and does not enable the share of those energy sources to be ascertained in real time, that is to say, when the system operator has to decide to curtail feed-in temporarily due to congestion.⁽²⁴⁾ Therefore, in my view, a ‘guarantee of origin’ cannot serve as a benchmark, as such, for determining the criteria for granting priority access to the electricity grid.

58. Sixth, the referring court enquires whether the legal rationale underlying the second subparagraph of Article 5(3) of Directive 2009/28 can be applied in respect of electricity produced only partly from biodegradable waste. I would point out that, under that provision, in multi-fuel plants using renewable and conventional sources, only the part of electricity produced from renewable energy sources is to be taken into account and that, for the purposes of that calculation, the contribution of each energy source is to be calculated on the basis of its energy content. In view of the significant freedom of action granted to Member States, I consider that, in the absence of any indication to the contrary in that directive, they may take the second subparagraph of Article 5(3) as a benchmark in order to implement priority access to the electricity grid.⁽²⁵⁾ In that context, a claim for compensation made by the operator of an electricity generating installation following a refusal to grant access to the grid due to congestion covers only the part of electricity produced from the biodegradable fraction of the waste mix.

59. In view of all the above, I propose that the following answer be given to the second to fifth questions referred for a preliminary ruling: Article 16(2)(c) of Directive 2009/28 must be interpreted as meaning that an electricity generating installation enjoys priority access to the grid only for electricity produced from the biodegradable fraction of the industrial and municipal waste used. It is for the Member States, in so far as the secure operation of the national electricity system so permits, to establish transparent and non-discriminatory criteria for the purpose of laying down the detailed rules for applying that priority access to such an installation.