Provisional text
OPINION OF ADVOCATE GENERAL
RANTOS
delivered on 7 May 2026 (1)
Case C‑199/25
Fluvius Halle-Vilvoorde, formerly Sibelgas,
Fluvius Kempen, formerly Intercommunale Vereniging voor de Energiedistributie in de Kempen en het Antwerpse (IVEKA),
Fluvius IMEWO, formerly Intercommunale Maatschappij voor Energievoorziening in West- en Oost-Vlaanderen (IMEWO),
Fluvius West, formerly Fluvius West and Intercommunale Maatschappij voor Gas en Elektriciteit van het Westen (GASELWEST),
Fluvius Zenne-Dijle, formerly Iverlek and Provinciale Brabantse Energiemaatschappij (P.B.E.),
Fluvius Midden-Vlaanderen, formerly Intercommunale Vereniging voor Energieleveringen in Midden-Vlaanderen (INTERGEM),
Fluvius Antwerpen,
Fluvius West,
Fluvius Limburg,
Provinciale Brabantse Energiemaatschappij CVBA (PBE)
v
De Vlaamse Nutsregulator, formerly de Vlaamse Regulator van de Elektriciteits- en Gasmarkt (VREG)
(Request for a preliminary ruling from the hof van beroep te Brussel (Court of Appeal, Brussels, Belgium))
( Reference for a preliminary ruling – Internal market for electricity – Regulation (EU) 2019/943 – Article 18(1) – Charges for access to networks, use of networks and reinforcement – Concept of ‘unrelated costs supporting unrelated policy objectives’ – Tariff methodology for the distribution of electricity using, for a significant component of the costs of network operators, a historical cost trend method – Possibility of maintaining temporarily the effects of national legislation, found to be incompatible with EU law, in order to avoid a situation of legal uncertainty )
I.      Introduction
1.        This request for a preliminary ruling, made by the hof van beroep te Brussel (Court of Appeal, Brussels, Belgium), concerns the interpretation of the first subparagraph of Article 18(1) of Regulation (EU) 2019/943. (2)
2.        The request has been made in the course of proceedings between ten Flemish distribution system operators (‘the applicant DSOs’) and the Vlaamse Nutsregulator, formerly the Vlaamse Regulator van de Elektriciteits– en Gasmarkt (Flemish Electricity and Gas Regulator) (‘the VREG’) concerning the legality of a decision of the VREG laying down the tariff methodology for the distribution of electricity and natural gas during the 2025 to 2028 regulatory period (‘the contested decision’).
3.         In that context, the referring court asks, in essence, first, whether national legislation which provides for the possibility for distribution systems operators (‘DSOs’) to pass on to their final customers the costs of the public service obligations (‘PSOs’) imposed on them by the Member State concerned, and a decision which establishes a tariff methodology on the basis of the historical cost assessment, are compatible with the first subparagraph of Article 18(1) of Regulation 2019/943, which has not yet been interpreted by the Court, and, second, whether it is possible to maintain temporarily the effects of that legislation in the event that it is found to be incompatible with EU law, in order to avoid a situation of legal uncertainty.
II.    Legal framework
A.      European Union law
1.      Regulation 2019/943
4.        Article 1 of Regulation 2019/943, entitled ‘Subject matter and scope’, is worded as follows:
‘This Regulation aims to:
(a)      set the basis for an efficient achievement of the objectives of the Energy Union … by enabling market signals to be delivered for increased efficiency, higher share of renewable energy, security of supply, flexibility, system integration through multiple energy carriers, sustainability, decarbonisation and innovation;
(b)      set fundamental principles for well-functioning, integrated electricity markets, which allow all resource providers and electricity customers non-discriminatory market access, … and enable market and sectoral integration and market-based remuneration of electricity generated from renewable sources;
…’
5.        Article 18 of that regulation, entitled ‘Charges for access to networks, use of networks and reinforcement’, is worded as follows:
‘1.      Charges applied by network operators for access to networks, including charges for connection to the networks, charges for use of networks, and, where applicable, charges for related network reinforcements, shall be cost-reflective, transparent, take into account the need for network security and flexibility and reflect actual costs incurred in so far as they correspond to those of an efficient and structurally comparable network operator and are applied in a non-discriminatory manner. Those charges shall not include unrelated costs supporting unrelated policy objectives.
Without prejudice to Article 15(1) and (6) of Directive
2012/27/EU [(3)] and the criteria in Annex XI to that Directive the method used to determine the network charges shall neutrally support overall system efficiency over the long run through price signals to customers and producers and in particular be applied in a way which does not discriminate positively or negatively between production connected at the distribution level and production connected at the transmission level. …
2.       Tariff methodologies shall reflect the fixed costs of transmission system operators and distribution system operators and shall provide appropriate incentives to transmission system operators and distribution system operators over both the short and long run, in order to increase efficiencies, including energy efficiency, to foster market integration and security of supply, to support efficient investments, …
…
4.      When setting the charges for network access, the following shall be taken into account:
(a)      payments and receipts resulting from the inter-transmission system operator compensation mechanism;
(b)      actual payments made and received as well as payments expected for future periods, estimated on the basis of previous periods.
…
7.      Distribution tariffs shall be cost-reflective taking into account the use of the distribution network by system users including active customers. …
8.      Distribution tariff methodologies shall provide incentives to distribution system operators for the most cost-efficient operation and development of their networks including through the procurement of services. For that purpose, regulatory authorities shall recognise relevant costs as eligible, shall include those costs in distribution tariffs, and may introduce performance targets in order to provide incentives to distribution system operators to increase efficiencies in their networks, …’
2.      Directive (EU) 2019/944
6.        Article 2 of Directive (EU) 2019/944, (4) entitled ‘Definitions’, states, in point 57, that the concept of ‘electricity undertaking’ must be understood as meaning ‘a natural or legal person who carries out at least one of the following functions: generation, transmission, distribution, …’
7.        Article 9 of that directive, entitled ‘Public service obligations’, provides in paragraphs 2 and 3:
‘2.      Having full regard to the relevant provisions of the TFEU, in particular Article 106 thereof, Member States may impose on undertakings operating in the electricity sector, in the general economic interest, public service obligations which may relate to security, including the security of supply, regularity, quality and price of supplies and environmental protection, including energy efficiency, energy from renewable sources and climate protection. Such obligations shall be clearly defined, transparent, non-discriminatory and verifiable, and shall guarantee equality of access for electricity undertakings of the Union to national consumers. …
3.      Where financial compensation, other forms of compensation and exclusive rights which a Member State grants for the fulfilment of the obligations set out in paragraph 2 of this Article or for the provision of universal service as set out in Article 27 are provided, this shall be done in a non-discriminatory and transparent way.’
8.        Article 57 of that directive, entitled ‘Designation and independence of regulatory authorities’, provides, in paragraph 4:
‘Member States shall guarantee the independence of the regulatory authority and shall ensure that it exercises its powers impartially and transparently. For that purpose, Member States shall ensure that, when carrying out the regulatory tasks conferred upon it by this Directive and related legislation, the regulatory authority:
(a)      is legally distinct and functionally independent from other public or private entities;
(b)      ensures that its staff and the persons responsible for its management:
(i)      act independently from any market interest; and
(ii)      do not seek or take direct instructions from any government or other public or private entity when carrying out the regulatory tasks. That requirement is without prejudice to close cooperation, as appropriate, with other relevant national authorities or to general policy guidelines issued by the government not related to the regulatory powers and duties under Article 59.’
9.        Article 59 of that directive, entitled ‘Duties and powers of the regulatory authorities’, provides, in paragraph 1(a):
‘The regulatory authority shall have the following duties:
(a)      fixing or approving, in accordance with transparent criteria, transmission or distribution tariffs or their methodologies, or both.’
B.      Belgian law
10.      Article 4.1.30(1) of the decreet van 8 mei 2009 houdende algemene bepalingen betreffende het energiebeleid (Energiedecreet) (Decree of 8 May 2009 laying down general provisions on energy policy (Energy Decree)) (5), in the version applicable to the facts in the main proceedings (‘the Energy Decree’), states:
‘The [VREG] shall establish a tariff methodology and exercise its powers in respect of tariffs with a view to promoting stable and predictable regulation which contributes to the proper functioning of the liberalised market and enables distribution system operators to make the necessary investments in their distribution systems.’
11.      Article 4.1.32(1) of that decree provides:
‘The [VREG] shall establish the tariff methodology taking into account the following guidelines:
…
5°      tariffs shall reflect the costs actually incurred, provided that these correspond to those of a comparable efficient entity or activity;
…
10°      costs relating to the implementation of the budget for public service tasks, imposed by or pursuant to the Decree, which are not financed by taxes, duties, subsidies, contributions and levies, shall be included in the tariffs in a transparent and non-discriminatory manner after verification by the [VREG]:
…
19°      tariffs shall not contain any incentive which is detrimental to overall efficiency, including the energy efficiency of the generation, distribution and supply of electricity …’
12.      Article 4.1.34(4) of that decree provides:
‘The Court of Appeal may, at the request of a party or of its own motion, rule that the legal effects of the decision that has been wholly or partially annulled be maintained in whole or in part, or are maintained provisionally for a period it shall decide. However, that measure may be ordered only on exceptional grounds that justify a departure from the principle of legality, based on a specially reasoned decision adopted after hearing both parties to the proceedings. The decision shall also take into account the interests of third parties.’
III. The dispute in the main proceedings, the questions referred for a preliminary ruling and the procedure before the Court
13.      The applicant DSOs were appointed by the VREG to operate the electricity and natural gas distribution networks in specific areas located in Flanders (Belgium).
14.      The operation of those networks entails costs for the applicant DSOs, which may be recovered from the users of those networks, subject to certain limits and conditions, by means of network tariffs. However, since the applicant DSOs constitute legal monopolies, the VREG regulates their network tariffs by determining the applicable tariff methodology. That methodology, which is generally established for a period of four years, fixes the level of revenue which the applicant DSOs are authorised to receive by means of network tariffs paid by distribution system users in order to cover their operating costs.
15.      The authorised revenue consists of a part corresponding to exogenous costs, namely the costs over which the applicant DSOs have no influence, and a part corresponding to endogenous costs, namely reasonable and necessary costs associated with network and data management, thus costs which the applicant DSOs may be able to influence. (6)
16.      On 21 June 2024, the chair and a member of the VREG board of directors signed, in accordance with the Energy Decree, the contested decision, which sets out the tariff methodology for the distribution of electricity and natural gas for the period 2025 to 2028. That tariff methodology includes formulas for calculating the authorised revenue intended to cover the reasonable and efficient endogenous costs of the applicant DSOs, namely the maximum endogenous costs that the latter may pass on to distribution system users.
17.      To that end, that tariff methodology takes into account the evolution of the costs incurred by the applicant DSOs. More specifically, the VREG, first, takes into consideration the evolution of endogenous sector costs, namely the aggregated endogenous costs of all Flemish DSOs for the same regulated activity during the previous tariff period, in the present case the period 2019 to 2023. Second, the VREG provides, throughout the 2025 to 2028 regulatory period, for the basic part of the permitted income for endogenous costs to be adjusted annually according to inflation, with the result that that basic part is corrected ex post according to actual inflation. Third, in addition to changes in historical costs, the VREG also takes into account an efficiency incentive known as the ‘frontier shift’, which reflects the increase in productivity achieved by the best performing undertakings by applying best practices (technological progress) and which, according to the VREG, is necessary to compensate for the reduced competition between the applicant DSOs. Fourth and lastly, five additional endogenous items, which are not relevant in the present case, are added to the basic part of the permitted income for endogenous costs.
18.      On 19 July 2024, the applicant DSOs brought an action before the hof van beroep te Brussel (Court of Appeal, Brussels), the referring court, seeking the annulment of the contested decision. They submit, inter alia, that the tariff methodology applied by the VREG to fix the tariffs for the distribution of electricity and natural gas for the period 2025 to 2028 infringes Articles 4.1.30 and 4.1.32 of the Energy Decree, Directive 2019/944, the principle of tariffs reflecting costs, as provided for in Article 18 of Regulation 2019/943, and several principles relating to good administration.
19.      For its part, the VREG submits, inter alia, that the tariff methodology established for the period 2025 to 2028 infringes the second sentence of the first subparagraph of Article 18(1) of Regulation 2019/943 in that, in accordance with Article 4.1.32(1), point 10, of the Energy Decree, the tariffs include unrelated costs supporting unrelated policy objectives. In that regard, the VREG submits that the national legislation at issue in the main proceedings imposes various PSOs on the applicant DSOs, for which they are granted compensation financed in part by the resources made available through the Energiefonds (Energy Fund) and by the general expenditure budget of the Vlaamse Gewest (Flemish Region). However, after that compensation has been deducted, the remaining costs relating to financial PSOs are passed on in the network tariffs for electricity. According to the VREG, the majority of those PSOs pursue social and environmental objectives, which therefore have no connection with the operation of distribution systems.
20.      In those circumstances, the referring court asks, in the first place, whether the national legislation at issue in the main proceedings is compatible with the second sentence of the first subparagraph of Article 18(1) of Regulation 2019/943, in accordance with which network tariffs must not include ‘unrelated costs supporting unrelated policy objectives’, a concept which is not defined by that regulation. In its view, the expression ‘unrelated policy objectives’ refers to purposes unrelated to the development and operation of the networks themselves. That court observes, in that regard, that the promotion of the use of renewable energy sources, inter alia through the compulsory purchase of ‘green’ certificates and combined heat and power certificates, appears to pursue energy policy objectives which are distinct from those relating to the development or efficient operation of distribution systems. Thus, that court asks whether the ‘unrelated costs’ relating to PSOs, which have no connection with network operation and which are, in Belgium, passed on in the tariffs under the Energy Decree, are compatible with that provision.
21.      In the second place, the referring court questions the compatibility, in the light of the first sentence of the first subparagraph of Article 18(1) of Regulation 2019/943, of a tariff methodology based on the historical costs of the applicant DSOs, in the absence of verification as to their efficiency. That provision requires that the costs passed on to users correspond to those of an efficient and structurally comparable network operator, which means that tariffs cannot exceed the level which would be reached in a competitive market. In that regard, while acknowledging that the use of historical empirical data may be relevant, it questions whether a tariff regulation based exclusively on historical costs, without a mechanism for assessing their efficiency, is actually consistent with the objective of that regulation and, more broadly, with the very purpose of any regulation applicable to a monopolistic market, which is to prevent the fixing of prices higher than those which would prevail in a competitive context.
22.      In the third and last place, the referring court raises the question of the temporary maintenance of the effects of the tariff methodology at issue in the present case. In its view, and in accordance with the case-law of the Court, (7) overriding considerations of legal certainty appear to justify the temporary maintenance of the effects of Article 4.1.32(1), point 10, of the Energy Decree and/or of the contested decision, should the Court find them to be incompatible with EU law. The referring court points out, in that regard, that an unmodulated annulment could undermine legal certainty. (8)
23.      In those circumstances, the hof van beroep te Brussel (Court of Appeal, Brussels) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:
‘(1)      Is [the second sentence of the first subparagraph of Article 18(1)] of Regulation [2019/943] to be interpreted as precluding a national rule such as Article 4.1.32, § 1, point 10 of the [Energy Decree] which provides that the costs of the [PSOs] imposed by or pursuant to the Decree, which are not financed by taxes, duties, subsidies, contributions and levies, are to be included in the tariffs?
(2)      Is [the first sentence of the first subparagraph of Article 18(1)] of Regulation [2019/943] to be interpreted as precluding the devising by a regulatory authority of a tariff methodology for the distribution of electricity that, with regard to a significant component of the costs of [DSOs] subject to revenue regulation, uses a historical cost trend method (which determines revenues on the basis of past costs), per se, or is the application of this method to be supported by verification of the level of the historical costs with regard to their efficiency?
(3)      If, on the basis of the answers to the questions set out above, the Brussels Court of Appeal were to come to the conclusion that the VREG is in breach of one or more of the obligations arising from the provisions cited in those questions, would it be able to temporarily maintain their effects in order to avoid legal uncertainty?’
24.      Written observations were submitted to the Court by the applicant DSOs, the VREG, the Belgian and Finnish Governments and the European Commission. Those parties also presented oral argument at the hearing held on 11 February 2025.
IV.    Analysis
A.      The first question referred for a preliminary ruling
1.      Admissibility
25.      As a preliminary point, although no objection of inadmissibility has been raised by the parties to the proceedings, I consider it necessary to examine the admissibility of the first question referred for a preliminary ruling.
26.      In that regard, I would point out that, in accordance with the settled case-law of the Court, in proceedings under Article 267 TFEU, it is solely for the national court before which a dispute has been brought, and which must assume responsibility for the subsequent judicial decision, to determine, in the light of the particular circumstances of the case, both the need for a preliminary ruling in order to enable it to deliver judgment and the relevance of the questions which it submits to the Court. Consequently, where the questions submitted concern the interpretation of EU law, the Court is, in principle, bound to give a ruling. (9) Nevertheless, the Court must examine the circumstances in which cases are referred to it by the national court, in order to assess whether it has jurisdiction or whether the request submitted to it is admissible. The Court may, in particular, find it necessary to examine whether the provisions of EU law to which the questions referred relate may be applied by the referring court for the purpose of resolving the dispute in the main proceedings. If they cannot, those provisions are irrelevant in resolving that dispute and the questions referred for a preliminary ruling are not necessary to enable the referring court to give judgment, with the result that those questions must be held to be inadmissible. (10)
27.      In the present case, it is apparent from the order for reference that, in the context of the dispute before the referring court, the VREG challenges the legality, in the light of the second sentence of the first subparagraph of Article 18(1) of Regulation 2019/943, of Article 4.1.32(1), point 10, of the Energy Decree, a provision which allows the costs associated with PSOs imposed on the DSOs by the Member State concerned to be taken into account in the network tariffs, where those costs are not financed by taxes, duties, subsidies, contributions and levies.
28.      It must be observed that the Energy Decree served as the basis for the introduction of a scheme to promote the production of electricity from renewable sources, which was notified by the competent Belgian authorities to the Commission and was the subject of Decision C(2018) 1003 final of 16 February 2016 on State aid SA.46013 (2017/N) – Belgium, Green electricity certificates and CHP certificates in Flanders (‘the Commission’s authorisation decision’). (11) By that decision, the Commission decided not to raise objections to that scheme, having found that it was compatible with the internal market under Article 107(3)(c) TFEU. (12)
29.      To that effect, I note that, as is apparent from the Court’s settled case-law, within the system established by the FEU Treaty for monitoring State aid, the national courts and the Commission fulfil complementary but separate roles. (13) In particular, national courts ensure the safeguarding, until the final decision of the Commission, of the rights of individuals faced with a possible breach by State authorities of the prohibition laid down by Article 108(3) TFEU. For this purpose, proceedings may be commenced before national courts requiring those courts to interpret and apply the concept of ‘State aid’, contained in Article 107(1) TFEU, in order to determine whether a State measure introduced without observance of the preliminary examination procedure provided for in Article 108(3) TFEU ought or ought not to have been subject to this procedure. By contrast, national courts do not have jurisdiction to give a ruling on whether aid measures or a State aid regime are compatible with the internal market. Indeed, in accordance with equally settled case-law of the Court, that assessment falls within the exclusive competence of the Commission, subject to review by the EU judicature. (14)
30.      Moreover, it is also settled case-law of the Court that the procedure under Article 108 TFEU must never produce a result which is contrary to the specific provisions of the FEU Treaty. Accordingly, State aid which, as such or by reason of some modalities thereof, contravenes provisions or general principles of EU law cannot be declared compatible with the internal market. Where the modalities of an aid measure or an aid scheme are so indissolubly linked to the object of the aid or the scheme, or to their functioning, that it is impossible to assess them separately, their effect on the compatibility or incompatibility of the aid or scheme viewed as a whole must necessarily be assessed by means of the procedure prescribed in Article 108 TFEU. (15) The assessment of such modalities therefore falls outside the jurisdiction of the national courts. (16)
31.      In the context of the dispute in the main proceedings, it is therefore necessary to ascertain whether the possibility of including, in the network tariffs, the costs relating to the discharge of the PSOs imposed on the applicant DSOs by the State under the Energy Decree may be assessed by the referring court in the light of the second sentence of the first subparagraph of Article 18(1) of Regulation 2019/943, even though that decree has already been the subject of an authorisation decision by the Commission finding it compatible with the internal market.
32.      In that regard, I would point out that, in the judgment in Tiberis Holding, the Court held that the request for a preliminary ruling made by the Consiglio di Stato (Council of State, Italy) was inadmissible on the ground that, in essence, the interpretation of Article 3 of Directive 2009/28/EC (17) and of Article 4 of Directive (EU) 2018/2001 (18), which was sought by that court, was not relevant to the resolution of the dispute in the main proceedings, since EU law precludes the referring court from assessing whether the negative incentive mechanism at issue in that case complies with those provisions, that mechanism being inextricably linked to the functioning of the State aid scheme which the Commission declared compatible with the internal market by Decision C(2016) 2726 final of 28 April 2016 on State aid SA.43756 (2015/N) – Support to electricity from renewable sources in Italy.
33.      More specifically, the Court held, first, that to allow the Consiglio di Stato (Council of State) to review the lawfulness, in the light of Article 3 of Directive 2009/28, of the negative incentive mechanism concerned would amount to giving that court the power to substitute its own assessment for that of the Commission in its decision and thus to encroach on that institution’s exclusive competences relating to the assessment of the compatibility of State aid with the internal market. (19) It considered, second, that any amendment to that negative incentive mechanism would, as a result of any increase in the aid intensity which might result from it, be liable to affect the assessment of its compatibility with the internal market and would thus constitute ‘new aid’ subject to the notification obligation, the compatibility of which with the internal market falls within the exclusive competence of the Commission, subject to review by the EU judicature. (20) That case-law makes it possible to clearly identify the circumstances in which a national court, hearing a case raising a question concerning the compatibility of national legislation with EU law, is able to rule where that legislation concerns a State aid measure the compatibility of which has previously been examined by the Commission.
34.      I would point out, in that regard, that the support scheme for renewable energy introduced by the Belgian Government and approved by the Commission is intended to encourage the production of electricity in photovoltaic installations through a purchase obligation and a guaranteed minimum price. It is apparent, in particular, from the Commission’s authorisation decision that that scheme is based on the creation of a market for green certificates in which various energy market players participate and in which the system operators are legally required to purchase the certificates at a guaranteed minimum price when producers cannot find buyers on the market. (21) Following a thorough analysis of the relevant provisions of the Energy Decree, and of the specific functioning of the renewable energy support mechanism, including the role assigned to network operators in the context of the purchase of green certificates, the Commission concluded that that scheme is compatible with the rules relating to State aid.
35.      Moreover, it follows in particular from the Commission’s authorisation decision that the buy-back obligation imposed on DSOs by the Energy Decree is of particular importance in the context of the operation of the aid scheme in question and was taken into account in the assessment of the compatibility and proportionality of the notified scheme. Since the Flemish DSOs have been entrusted with task of acting as a ‘buyer of last resort’, in that they have to buy any amount of certificates offered to them by market parties at a legally set minimum price, (22) their intervention in the market constitutes a central element of the aid scheme covered by the Commission’s authorisation decision. (23)
36.      Although, in the light of the Court’s case-law referred to in point 30 of this Opinion, the PSO to buy back green certificates imposed on the DSOs by the Member State concerned is capable of constituting a modality which is inextricably linked to the functioning of the aid scheme in question, it must nevertheless be noted that, in the present case it is not the mechanism established by the Energy Decree laying down the obligation for DSOs to purchase green certificates which is disputed in the light of Article 18(1) of Regulation 2019/943, (24) but the possibility of including in network tariffs the costs of the PSOs imposed on the applicant DSOs by that
decree and the arrangements for their integration. (25) The latter parameter does not constitute, within the meaning of the case-law of the Court, a modality which is inextricably linked to the functioning of the aid scheme in question on the basis of which the Commission assessed its conformity and compatibility with the provisions on State aid.
37.      The way in which PSO costs were accounted for in electricity tariffs was not examined in the Commission’s authorisation decision. Even assuming that the aid scheme notified to the Commission included information relating to the way in which those costs are accounted for, which, however, is not apparent from that decision, the Commission would not, in any event, have been able to find a possible incompatibility of the Energy Decree with respect to the prohibition, now laid down in Article 18 of Regulation 2019/943, on including in the network charges ‘unrelated costs supporting unrelated policy objectives’. (26)
38.      I would add that the case-law arising from the judgment in Tiberis Holding could become relevant only if the referring court were to find that a possible incompatibility of the Energy Decree with Article 18(1) of Regulation 2019/943 would be liable to affect the intensity or modalities of the aid approved by the Commission, in that it would entail an alteration of the amount of that aid or of the conditions on the basis of which its compatibility assessment was carried out and its approval was issued, or if it were to find that that potential incompatibility would be likely to influence the assessment of the compatibility of the aid scheme at issue with the internal market, in which case it could be considered to be ‘new aid’, with the consequences arising therefrom both as regards the jurisdiction of the national court and the inadmissibility of the first question referred for a preliminary ruling. (27) The file submitted to the Court does not contain any information to support such a conclusion.
39.      Therefore, I consider, in the light of the foregoing considerations, that the grounds which led to the conclusion that the request for a preliminary ruling in the case which gave rise to the judgment in Tiberis Holding was inadmissible cannot be transposed to the present case and, therefore, that the first question referred for a preliminary ruling is admissible.
2.      Substance
40.      At the outset, I note that the interpretation sought by the referring court relates exclusively to the first subparagraph of Article 18(1) of Regulation 2019/943. However, like the parties to the proceedings, I am of the opinion that, in order to provide a useful answer to that court, account must be taken of both Article 9 of Directive 2019/944, which establishes the legal framework applicable to PSOs in the energy sector, and Articles 57 and 59 of that directive, which govern, respectively, the designation and independence of the national regulatory authorities, and the extent of the duties granted to them.
41.      That said, the Court is called upon to interpret the first subparagraph of Article 18(1) of Regulation 2019/943 and to examine its interaction with the abovementioned provisions of Directive 2019/944, in order, first, to assess whether the costs of the PSOs fall within the concept of ‘network charges’, and, second, to establish whether the setting of those charges does in fact fall within the scope of the duties conferred on the national regulatory authorities and, if so, to determine the extent to which it is likely to undermine the decision-making autonomy and independence of those authorities.
(a)    The consideration of PSOs in network charges
42.      The first issue raised by the referring court concerns the compatibility of the Energy Decree with Article 18(1) of Regulation 2019/943, in that that decree provides that the costs of PSOs relating to renewable energy may be passed on in network tariffs, even though those PSOs are unrelated to the operation of the distribution system and that that provision prohibits the inclusion in network charges of ‘unrelated costs supporting unrelated policy objectives’.
43.      I would point out that, in accordance with the Court’s settled case-law, in interpreting a provision of EU law, it is necessary to consider its wording, the context in which it occurs and the objectives pursued by the rules of which it is part. (28)
44.      In the first place, as regards the wording of the first subparagraph of Article 18(1) of Regulation 2019/943, that provision states that charges applied by network operators for access to networks, including charges for connection to the networks, charges for use of networks, and, where applicable, charges for related network reinforcements, must be cost-reflective, transparent, take into account the need for network security and flexibility and reflect actual costs incurred in so far
as they correspond to those of an efficient and structurally comparable network operator and are applied in a non-discriminatory manner. Those charges must not include unrelated costs supporting unrelated policy objectives.
45.      It is apparent, at first glance, from the wording of that provision that, although the EU legislature intended to regulate network charges by requiring that the costs associated with them be related to the actual operation of the network and that those charges must not, inter alia, include unrelated costs supporting unrelated policy objectives, the concepts of ‘network charges’, ‘unrelated costs’ and ‘unrelated policy objectives’ are not defined in that regulation.
46.      In the second place, as regards the context of the first subparagraph of Article 18(1) of Regulation 2019/943, that provision forms part of Chapter III
thereof, which concerns access to the network and possible cases of network congestion and, more specifically, in Section II of that chapter, which is entitled ‘Network charges and congestion income’, comprising two articles.
47.      It appears in that regard that, although paragraphs 2 to 8 of that provision provide further clarification as to the methodology to be followed in order to determine network charges and, more generally, guidance on electricity transmission and distribution tariffs, those factors do not, on their own, provide a clear answer to the first question referred for a preliminary ruling.
48.      In those circumstances, and in order to examine fully the context of the first subparagraph of Article 18(1) of Regulation 2019/943, account must also be taken of certain provisions of Directive 2019/944.
49.      I note, as regards the methodology underlying tariffs, that, in accordance with point 3 of Annex I to that directive, which sets out the minimum requirements for billing and billing information, the customer’s price is the sum of the three main components, namely, first, the ‘energy and supply’ component, second, the ‘network’ component (transmission and distribution) and, third, the component comprising ‘taxes, levies, fees and charges’. Moreover, as recalled in that point 3, the relevant definition of those components is set out in Annex II to Regulation (EU) 2016/1952, (29) which expressly provides that the third component (‘taxes, fees, levies and charges’) may include, inter alia, charges relating to the promotion of renewable energy sources.
50.      As regards, more specifically, PSOs, Article 9(2) of Directive 2019/944 provides that Member States are entitled to impose such obligations, including in relation to energy from renewable sources, on electricity and natural gas undertakings. (30) Article 9(3) of that directive states, moreover, that, where financial compensation, other forms of compensation and exclusive rights are granted by a Member State for the fulfilment of the obligations set out in paragraph 2 of that article, this is to be done in a non-discriminatory and transparent way.
51.      It thus follows from a combined reading of Article 18 of Regulation 2019/943 and the abovementioned provisions of Directive 2019/944 that, although the concepts of ‘network charges’, ‘tariffs’ and ‘tariff methodologies’ are not defined by Regulation 2019/943, nor are they always used consistently, (31) the network ‘tariffs’ or ‘charges’ referred to in Article 18(1) of that regulation constitute only one of the three main components of the total billing.
52.      Moreover, Article 9 of Directive 2019/944 grants Member States considerable discretion both in defining the type of PSO they wish to impose on DSOs and in the arrangements for financing those PSOs. (32) It follows that that directive does not preclude, in principle, national legislation under which DSOs may pass on to final customers the costs of the PSOs imposed on them by the Member State concerned, including in the form of charges, provided that the parameters and arrangements for such financing satisfy the conditions set out in Article 9(3) of that directive.
53.      In the third and last place, as regards the objectives pursued by Regulation 2019/943, it is apparent from Article 1 thereof that that regulation aims inter alia to set the basis for an efficient achievement of the objectives of the Energy Union and the objective of the European Union to become climate neutral. It seeks, in particular, to enable market signals to be delivered for increased efficiency, higher share of renewable energy sources, security of supply, flexibility, sustainability, decarbonisation and innovation.
54.      In the light of the considerations set out in the preceding points of this Opinion, I consider that the following conclusions should be drawn.
55.      In the first place, I note, as stated in points 44 and 45 of the
present Opinion, that Article 18(1) of Regulation 2019/943 applies only to ‘charges’ relating to the use of, connection to and reinforcement of the network. That provision therefore covers only costs actually incurred by the network operator which are closely linked to the operation of the distribution system and does not govern other tariff components which are unrelated to the actual use of the network. It follows that, a priori, PSO costs in respect of support for renewable energy charged by the network operator do not form part of the ‘charges’ referred to by that provision and therefore do not fall within its scope. (33)
56.      It is also apparent from Article 18(1) of Regulation 2019/943 that Member States must not include in the charges for access to the network referred to in that provision costs which are not strictly linked to the operation of the network and which pursue ‘unrelated … objectives’. That restriction appears to, first, reflect the intention of the EU legislature to prevent those charges from being diverted from their intended purpose and used as a residual mechanism for financing public policies with no apparent link to the electricity distribution and transmission system and, second, to ensure transparency in pricing, which constitutes an essential element for the proper functioning of the electricity markets at EU level. (34)
57.      In the second place, I note that the EU legislature has laid down certain rules governing billing, both for the network operator and for the final consumer, which require in particular that network-related charges and those relating to PSOs in respect of support for renewable energy are presented in a transparent manner as charges distinct from network tariffs and are not included in those tariffs.
58.      The particular feature of the present case is that the costs associated with PSOs appear to have been included not in the category relating to ‘taxes, charges and tariffs’ (which corresponds to the third charging component in accordance with point 3 of Annex I to Directive 2019/944), (35) which, according to all the parties to the proceedings, would lead to a solution consistent with EU law, (36) but in the category relating to ‘network charges’ (which corresponds to the second charging component in accordance with point 3 of Annex I to that directive), (37) which must, in principle, include only costs related to the network.
59.      Although such a situation may, at first sight, give rise to questions as to the compatibility of the national legislation at issue in the main proceedings with Article 18(1) of Regulation 2019/943, in my view it remains to be clarified how the charges relating to PSOs were bundled into the network tariffs and, in particular, whether those charges actually influence the fixing of those tariffs by the VREG. (38) To limit oneself solely to the formal classification of those costs in order to conclude that they are incompatible with that provision, on the ground that the costs were accounted for in another category, even though they were recorded in a manner that is completely separate, would, in my view, constitute excessive formalism which would run counter to the effective application of both Regulation 2019/943 and Directive 2019/944. (39)
60.      It is thus for the referring court to examine not only the formal classification and purpose of the levy in question, as well as its link to the network’s activity, but also the way in which those same costs are incorporated into the tariff structure. If those network charges cannot be dissociated from other costs pursuing objectives independent of the network, that would, a priori, be incompatible with the first subparagraph of Article 18(1) of Regulation 2019/943. By contrast, that finding does not apply, in my view, in the same way where non-network costs, such as, for example, those relating to PSOs, are clearly separated and can be clearly distinguished from network charges or tariffs. (40) However, and subject to the checks which it is for the referring court to carry out in that regard, it cannot be ruled out that the situation at issue in the main proceedings falls within the latter situation. (41)
(b)    The impact of the inclusion of PSOs in network tariffs in the light of the powers and role conferred on the national regulatory authority
61.      The second issue raised by the referring court concerns the question whether the inclusion of PSO costs in network charges, as provided for by the national legislation at issue in the main proceedings, is likely to undermine the independence or decision-making autonomy of the national regulatory authority in the fixing of network tariffs, in accordance with the requirements set out in Article 57(4) and (5) and Article 59(1)(a) of Directive 2019/944. (42)
62.      As a preliminary point, I recall that Article 57(4) of Directive 2019/944 provides, in essence, that the Member States are to guarantee the independence of the national regulatory authority and, to that end, are to ensure that, when carrying out the regulatory tasks conferred on them by that directive and related legislation, national regulatory authorities are legally distinct and functionally independent from other public or private entities and that their staff and the persons responsible for their management act independently from any market interest and do not seek or take direct instructions from any government or other public or private entity when carrying out those tasks. (43) However, under Article 57(4)(b)(ii) of that directive, that latter requirement is without prejudice to close cooperation, as appropriate, with other relevant national authorities or general policy guidelines issued by the government not related to the regulatory powers and duties under Article 59 of the directive, which include the duty, set out in Article 59(1)(a) thereof, to fix or approve transmission or distribution tariffs or their methodologies. (44)
63.      It follows that, first, regulatory authorities need to be able to take decisions in relation to all relevant regulatory issues if the internal market for electricity is to function properly, and need to be fully independent from any other public or private interests and, second, that Directive 2019/944 does not deprive Member States of the possibility of establishing and issuing their national energy policy or determining the policy framework in which those authorities are to operate. Consequently, Member States are free to adopt their own rules relating to the national electricity market, provided that they comply with the duties and powers conferred on the regulatory authorities by that directive. (45)
64.      It should be noted in that regard that, while it is not disputed that the fixing of distribution tariffs and the establishment of the applicable tariff methodology in relation to connection fees fall, pursuant to Article 59(1)(a) of that directive, within the exclusive competence of the national regulatory authorities, which have considerable discretion in that regard, that competence cannot automatically extend to other aspects of energy policy which are not linked to the duties conferred on those authorities under that provision and which, consequently, fall outside their competence and the determination of which is, in principle, a prerogative of the legislature or the executive. That is the case, in particular, with regard to the fixing of costs relating to PSOs in respect of support for renewable energy and the arrangements for recovering those costs.  The way in which a Member State intends to support the renewable energy market within its territory, whether through direct subsidies, tax mechanisms or, as in the present case, a parafiscal measure consisting of the passing on of costs to final consumers, is a matter of pure energy policy choice falling outside the competence of the national regulatory authorities. (46)
65.      In other words, although the setting of the network ‘charges’ referred to in Article 18(1) of Regulation 2019/943 clearly falls within the competence of the national regulatory authorities pursuant to Article 59(1)(a) of Directive 2019/944, that cannot be the case for ‘taxes or other charges’ which are not linked to access to or use of the network and which, as a result, do not, in principle, fall within the scope of Article 18(1) thereof. (47)
66.      That finding does not, however, prevent Member States from conferring such powers on national regulatory authorities and from making, as in the present case, (48) the regulation of certain tariff aspects which do not necessarily fall under the initial duties defined in Article 59 of Directive 2019/944 subject to the supervision, or even control, of the competent national regulatory authority. (49) No provision of EU law appears to preclude Member States from empowering the competent national authority to regulate tariffs linked to PSOs.
67.      The fact, referred to in point 58 of the present Opinion, that the charges relating to PSOs were accounted for not in the third tariff component but in the network tariffs, is not such as to call into question the foregoing analysis and cannot, in itself, lead to a finding that the national legislation at issue in the main proceedings is incompatible with Article 57(4) and Article 59(1)(a) of Directive 2019/944. Provided that the referring court confirms that the costs associated with the PSOs, although formally included in the network charges, have in reality been clearly separated from them, with the result that they do not specifically affect the methodology for calculating and fixing network charges or tariffs, such a situation cannot be equated with that in which the legislature or the executive intended to encroach upon the powers of the national regulatory authority or undermine its authority in relation to the fixing or approval of tariff methodologies.
68.      I would point out, lastly, that, if it were concluded that the costs of the PSOs, which are intended to be passed on to final customers, fall within the scope of the duties of the national regulatory authorities, the case-law of the Court acknowledges that, in certain cases, even in areas falling within the competence of the national regulatory authorities, the exercise by a State of its powers to establish its national energy policy may have repercussions on the costs of operating the electricity system, without such intervention being, as such, incompatible with Article 57(4) and (5) of Directive 2019/944. (50)
69.      In that regard, I note that, in the context of a dispute concerning the compatibility of Directive 2009/73/EC (51) with national legislation which consists, in essence, of State intervention in respect of the price of natural gas, the Court held that Article 3(1) to (3) of that directive (52), read in the light of Articles 36 and 38 of the Charter of Fundamental Rights of the European Union, must be interpreted as not precluding legislation of a Member State which provides that the costs associated with the natural gas storage obligations imposed on natural gas undertakings in order to ensure the security and regularity of natural gas supply in that Member State are to be borne entirely by those undertakings’ customers, who may be private individuals, provided that that legislation pursues an objective of general economic interest, that it complies with the requirements of the principle of proportionality and that the PSOs which it lays down are clearly defined, transparent, non-discriminatory, verifiable and guarantee equality of access for EU gas undertakings to national consumers. (53)
70.      In the light of the foregoing, I propose that the answer to the first question should be that the second sentence of the first subparagraph of Article 18(1) of Regulation 2019/943, and Article 57(4) and (5) and Article 59(1)(a) of Directive 2019/944, must be interpreted as not precluding the inclusion in network charges of the costs of the PSOs imposed on a network operator by a Member State on the basis of Article 9(2) of Directive 2019/944 and which are not financed by taxes, duties, subsidies, contributions and levies, provided that those costs are not integrated into the methodology for setting those charges and are clearly distinguished from those charges.
B.      The second question referred for a preliminary ruling
71.      By its second question, the referring court asks, in essence, whether the first sentence of the first subparagraph of Article 18(1) of Regulation 2019/943 must interpreted as precluding the devising by a regulatory authority of a tariff methodology for the distribution of electricity that, with regard to a significant component of the costs of DSOs subject to revenue regulation, uses a historical cost trend method (and thus determines revenues on the basis of past costs), per se, or whether the application of that method must be supported by verification of the level of the historical costs with regard to their efficiency.
72.      As a preliminary point, I note that the interpretation sought by the referring court relates solely to the first sentence of the first subparagraph of Article 18(1) of Regulation 2019/943, which requires charges for access to networks to reflect the costs of DSOs in so far as they correspond to those of an efficient and structurally comparable DSO. In order to provide a useful answer to that court, I consider that that question should be reformulated, referring not to Article 18(1) but rather to Article 18(2) to (8).
73.      I would point out, in that regard, that Article 18 of Regulation 2019/943 lists the general principles applicable to the fixing and approval of network access tariffs, which must inter alia reflect costs, foster market integration and ensure the security of supply, as well as encourage efficient use of the existing grid by means of appropriate price signals to users.
74.      I note, first, that Article 18 of that regulation does not impose a specific tariff methodology for the distribution of electricity which the national regulatory authority is required to follow. It is therefore for that authority to develop a methodology that meets all the requirements laid down in Article 18 of that regulation, including that relating to cost efficiency. (54) Moreover, given the complex and technical nature of its duties, that authority must have a broad discretion in determining that methodology. (55) In that context, the margin of discretion available to that authority must enable it to adjust the methodology used and the procedures for calculation according to the parameters which it considers relevant in the light of the objectives pursued both by EU law and by the applicable national legislation, including by taking into account the specific conditions existing on the national electricity market. (56)
75.      Second, I note that the mere fact that a methodology adopted by a national regulatory authority is based in part on historical data, used as a starting point for assessing the future costs of a DSO, (57) cannot, in itself, render it incompatible with Article 18 of that regulation. (58) That is the case in particular where that methodology does not preclude, as appears to be the case here, the consideration of adjustment factors for historical costs or additional criteria reflecting the fact that future market developments may differ from those observed in the past.
76.      Third, as is apparent from Article 18(1), (2) and (8) of Regulation 2019/943, in order for a tariff methodology to be compatible with that provision, that method must contain incentives for the network operator to increase efficiencies, over both the short and long term, of costs and investments. It should also be noted that, in the exercise of its broad discretion, recalled in point 74 of the present Opinion, the national regulatory authority may ensure the economic efficiency of DSOs in various ways.
77.      In the present case, it is apparent from the order for reference that the tariff methodology adopted by the VREG includes adjustment factors to ensure an improvement in overall efficiency, including the energy efficiency of the system, and also provides for a form of control over the costs incurred by the applicant DSOs which are passed on in electricity tariffs. (59)
78.      Fourth, I note that, although the referring court raises the question of the compatibility of the methodology applied by the VREG with the requirement laid down in the first subparagraph of Article 18(1) of Regulation 2019/943, in accordance with which the costs that may be passed on must correspond ‘to those of an efficient and structurally comparable network operator’, that question remains essentially theoretical, since that court has not ruled on the detailed arguments put forward by both the applicant DSOs and the VREG as regards the various parameters and modalities of the tariff methodology adopted by the VREG. (60)
79.      I also consider it important to point out, in that regard, that, although the Court of Justice has jurisdiction to interpret provisions of EU law, it is not for it to assess in abstracto the various parameters of the methodology adopted by the VREG, or to determine itself the specific methodology which that authority would be required to apply, or to rule on the appropriateness of alternative criteria which could have been used in the present case. The establishment of the appropriate methodology depends on a series of facts and technical parameters which are not available to the Court of Justice and, in any event, such a specific assessment is a matter for the referring court alone. It follows that it is for that court to verify whether the tariff methodology at issue in the present case satisfies the requirements laid down in Article 18 of Regulation 2019/943, in the light of all the facts available to it.
80.      In the light of the foregoing, I propose that the answer to the second question should be that Article 18 of Regulation 2019/943 must be interpreted as not precluding the devising, by a national regulatory authority, of a tariff methodology for the distribution of electricity that uses a historical cost trend method, in so far as that methodology provides for factors enabling those data to be adjusted, if necessary, to the costs of an efficient and structurally comparable DSO. It is for the national regulatory authority, subject to review by the national courts, to determine the appropriateness of the method used for the purposes of that calculation, on the basis of the relevant facts, while complying with the general principles for fixing tariffs established by that provision.
C.      The third question referred for a preliminary ruling
81.      By its third question, the referring court asks, in essence, whether it may, in order to avoid a situation of legal uncertainty, maintain temporarily the effects of a national provision, such as Article 4.1.32(1), point 10, of the Energy Decree, and/or the contested decision, where, in the light of a judgment of the Court delivered following a reference for a preliminary ruling, it proves to be incompatible with EU law.
82.      In that regard, and as the referring court has noted, that question is relevant only if, in the light of the answers given to the first two questions referred for a preliminary ruling, that court were to decide to annul the Energy Decree and/or the contested decision on the ground that one, or both, is incompatible with EU law.
83.      In the light of my proposed answers to the first and second questions referred for a preliminary ruling, there is no need to answer the third question.
V.      Conclusion
84.      In the light of the foregoing considerations, I propose that the Court of Justice should answer the questions referred for a preliminary ruling by the hof van beroep te Brussel (Court of Appeal, Brussels, Belgium) as follows:
(1)      The second sentence of the first subparagraph of Article 18(1) of Regulation (EU) 2019/943 of the European Parliament and of the Council of 5 June 2019 on the internal market for electricity, and Article 57(4) and (5) and Article 59(1)(a) of 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,
must be interpreted as
not precluding the inclusion in network charges of the costs of the public service obligations imposed on a network operator by a Member State on the basis of Article 9(2) of Directive 2019/944 and which are not financed by taxes, duties, subsidies, contributions and levies, provided that those costs are not integrated into the methodology for setting those charges and are clearly distinguished from those charges.
(2)      The second sentence of the first subparagraph of Article 18(1) of Regulation 2019/943
must be interpreted as
not precluding the devising, by a national regulatory authority, of a tariff methodology for the distribution of electricity that uses a historical cost trend method, in so far as that methodology provides for factors enabling those data to be adjusted, if necessary, to the costs of an efficient and structurally comparable distribution systems operator. It is for the national regulatory authority, subject to review by the national courts, to determine the appropriateness of the method used for the purposes of that calculation, on the basis of the relevant facts, while complying with the general principles for fixing tariffs established by Article 18 of that regulation.
1      Original language: French.
2      Regulation of the European Parliament and of the Council of 5 June 2019 on the internal market for electricity (OJ 2019 L 158, p. 54). It should be pointed out that that regulation has been the subject of successive modifications, of 23 June 2022 and 16 July 2024. However, since the referring court has identified the provisions in the initial version of that regulation as relevant, the present Opinion will be based on that initial version, in which it is made clear that the subsequent modifications do not affect the analysis.
3      Directive of the European Parliament and of the Council of 25 October 2012 on energy efficiency, amending Directives 2009/125/EC and 2010/30/EU and repealing Directives 2004/8/EC and 2006/32/EC
(OJ 2012 L 315, p. 1).
4      Directive 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).
5      Belgisch Staatsblad, 7 July 2009, p. 46192.
6      More specifically, endogenous costs consist of three main components: first, depreciation costs; second, operating expenses, including expenses and income falling under the headings of the minimum standard chart of accounts; and, third, the costs of invested capital.
7      The referring court refers, in that regard, to the judgments of 5 October 2023, Osteopathie Van Hauwermeiren (C‑355/22, EU:C:2023:737, paragraph 30), and of 12 September 2024, Casino de Spa and Others (C‑741/22, EU:C:2024:732, paragraphs 52, 53 and 58 to 62 and the case-law cited).
8      According to the VREG, developing a new tariff methodology would take at least two years, during which time network operators would likely have to finance their PSOs without the corresponding revenue, which could affect their solvency. Moreover, if the tariff methodology cannot be maintained temporarily, this could lead to retroactive adjustments of invoices.
9      See, inter alia, judgment of 1 August 2025, Tiberis Holding (C‑514/23, ‘the judgment in Tiberis Holding’, EU:C:2025:597, paragraph 33 and the case-law cited).
10      See judgment in Tiberis Holding (paragraph 35 and the case-law cited).
11      Authorisation for State aid pursuant to Articles 107 and
108 of the [FEU Treaty] – Cases where the Commission raises no objections (OJ 2018 C 360, p. 1). That decision is available on the Commission’s website:
https://ec.europa.eu/competition/state_aid/cases/271706/271706_1974009_131_2.pdf.
12      Moreover, it is important to note that the Commission’s authorisation decision remains applicable, since the approval was granted for a period of 10
years, in accordance with recital 7 of that decision.
13      See judgment in Tiberis Holding (paragraph 39 and the case-law cited).
14      See judgment in Tiberis Holding (paragraph 40 and the case-law cited).
15      See judgment in Tiberis Holding (paragraph 41 and the case-law cited). See, also, judgment of 11 September 2025, Austria v Commission (Paks II nuclear power station) (C‑59/23P, EU:C:2025:686, paragraphs 52 to 55, 70 and 71 and the case-law cited).
16      See judgment in Tiberis Holding (paragraph 42 and the case-law cited).
17      Directive of the European Parliament and of the Council of 23 April 2009 on the promotion of the use of energy from renewable sources and amending and subsequently repealing Directives 2001/77/EC and 2003/30/EC (OJ 2009 L 140, p. 16).
18      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).
19      See judgment in Tiberis Holding (paragraphs 44 to 50 and the case-law cited).
20      See judgment in Tiberis Holding (paragraphs 51 to 62 and the case-law cited).
21      The main features of the renewable energy support scheme can be summarised as follows. Electricity producers using renewable sources or cogeneration are allocated certificates for each unit of energy produced. Electricity suppliers, or network access holders, are subject to an annual obligation to hold and surrender a certain number of certificates, proportional to their supply volume, subject to payment of a fine. The certificates are, in principle, traded on a market, and their price is determined by supply and demand. If some certificates do not find a buyer on this market, the DSOs, legally obliged to purchase them at a guaranteed minimum price, intervene to stabilise the market. The costs incurred by the DSOs under this purchase obligation are then passed on to consumers through network tariffs.
See, with regard to the task entrusted to DSOs in the context of the operation of the aid scheme in question, recitals 8, 9, 36 and 75 of the Commission’s authorisation decision.
22      See recital 75 of the Commission’s authorisation decision.
23      It is apparent from recital 36 of the Commission’s authorisation decision that the market in question was, at the time, characterised by a surplus of certificates, which led to frequent recourse to the purchase obligation imposed on DSOs. This finding appears, for the rest, to be confirmed by the order for reference, which notes that the payments in question correspond to particularly large amounts, a circumstance which, in its view, could justify, where appropriate, a limitation in time on the effects of the forthcoming judgment, in the event that the Court’s answers lead to a finding that the aid scheme at issue in the main proceedings is incompatible with EU law. See, in this regard, paragraph 22 of the present Opinion.
24      None of the parties to the proceedings challenges, in the light of other provisions of EU law, that the Kingdom of Belgium is able to impose the PSOs in question. The same applies to the financing arrangements provided for by those PSOs and the possibility for DSOs to pass on the related costs to end consumers. As confirmed at the hearing, the issue at stake in the first preliminary question concerns how the costs related to public service obligations (PSOs) should be accounted for in electricity tariffs, as well as the consequences of including them in network tariffs, without in any way calling into question the existence of these PSOs or their financing arrangements, including the possibility of passing on the resulting costs to end consumers.
25      The first question referred for a preliminary ruling concerns whether the costs associated with buying back green certificates may be passed on in network tariffs in the light of Article 18(1) of Regulation 2019/943. Moreover, it is not apparent from any of the documents before the Court that, by its question, the referring court seeks to call into question the mechanism for buying back green certificates or the arrangements for its financing.
26      The provision applicable at the time of the adoption of the Commission’s authorisation decision, namely Article 14 of Regulation (EC) No 714/2009 of the European Parliament and of the Council of 13 July 2009 on conditions for access to the network for cross-border exchanges in electricity and repealing Regulation (EC) No 1228/2003 (OJ 2009 L 211, p. 15), was worded differently and did not provide for such a prohibition.
27      See judgments in Tiberis Holding (paragraphs 58, 60 and 61), and of 12 January 2023, DOBELES HES (C‑702/20 and C‑17/21, EU:C:2023:1, paragraphs 60 and 61).
28      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).
29      Regulation of the European Parliament and of the Council of 26 October 2016 on European statistics on natural gas and electricity prices and repealing Directive 2008/92/EC (OJ 2016 L 311, p. 1). Annex II to that regulation states that the ‘network’ price includes, inter alia, transmission and distribution tariffs. Moreover, ‘taxes, fees, levies and charges’ also include taxes, fees, levies or charges relating to the promotion of renewable energy sources, energy efficiency and CHP generation.
30      I would point out in that regard that Article 2(57) of Directive 2019/944 defines the concept of ‘electricity undertaking’ broadly, with the result that the PSOs referred to in Article 9 of that directive which are imposed on electricity undertakings may concern both system operators and other undertakings operating in the electricity sector.
31      Although the term ‘charges’ is used in Article 18(1) of Regulation 2019/943 to designate the costs related to the electricity transmission and distribution system, ‘tariff’ is used to designate those costs in Annex II to Regulation 2016/1952, to which point 3 of Annex I to Directive 2019/944 refers. The same applies to Article 59(1)(a) of that directive, which refers to transmission or distribution ‘tariffs’ without mentioning the network charges referred to in Article 18(1) of Regulation 2019/943. It must also be noted that the term ‘charge’ is, for its part, used to describe both costs relating to the network (within the meaning of Article 18(1) of that regulation) and costs relating to PSOs (in the context of the third tariff component, as provided for in point 3 of Annex I to Directive 2019/944 and Annex II to Regulation 2016/1952). I note, in that regard, that all the parties to the proceedings confirmed at the hearing that the terms ‘tariffs’ and ‘charges’ should, in their view, be understood as interchangeable.
32      This includes, inter alia, determining the arrangements for the reimbursement of the costs arising from their discharge.
33      That does not preclude certain PSOs from being implemented in the form of charges relating to the operation or the use of the network, which therefore fall within the scope of Article 18(1) of Regulation 2019/943, in particular where they are intended to cover the costs of investments necessary for the improvement or protection of the network or for the connection of customers in rural or remote areas.
34      I note, in that regard, that, in accordance with Article 18(9) and (10) of Regulation 2019/943, the European Union Agency for the Cooperation of Energy Regulators (ACER) is to provide a best practice report on transmission and distribution tariff methodologies. In its latest version, that report states that ‘costs if not related to network use can distort network tariff signals and/or lead to distributional effects [on the electricity market]’. See ACER report on network tariff practices entitled ‘Getting the signals right: Electricity network tariff methodologies in Europe’, of 26 March 2025 (‘the ACER report’), available only in English at: https://www.acer.europa.eu/sites/default/files/documents/Reports/2025-ACER-Electricity-Network-Tariff-Practices.pdf, in particular p. 29, paragraph 85.
35      See point 49 of the present Opinion.
36      Both the VREG and the Commission, which had initially submitted in their written observations that the inclusion of PSO costs in network charges would lead to incompatibility, according to the VREG, with Article 18(1) of Regulation 2019/943 and, according to the Commission, with Article 57(4) and (5) and Article 59(1)(a) of Directive 2019/944, confirmed at the hearing that the costs associated with PSOs could be passed on in full to end consumers within the framework of the third tariff component.
37      See point 49 of the present Opinion.
38      Although the referring court has not ruled in that regard, the positions of the parties differ as to how PSO costs are actually incorporated into network tariffs and the actual existence of a separate tariff for PSOs in Flanders, and as to the exact way in which those costs are accounted for. The applicant DSOs and the Belgian Government maintain that there is a separate ‘specific tariff’ for PSOs, claiming that the costs relating to those PSOs in no way affect the methodology for calculating network charges. That assertion is, however, contested by the VREG, which considers that the costs relating to PSOs are not subject to a separate tariff.
39      That is all the more so since the abovementioned provisions of EU law are not particularly clear, as stated in point 51 of the present Opinion.
40      That would be the case if the costs relating to PSOs, although formally linked to ‘network charges’, were accounted for separately from those charges.
41      I note, in that regard, that it is apparent from the ACER report, on which the VREG and the applicant DSOs and the Belgian Government rely, that, in Flanders, as in most Member States, costs which are not connected with the system are clearly separated from other network costs or charges. See, in that regard, paragraph 63 of that report and accompanying Figure 4, and Table 59 of Annex 1 thereto, in particular p. 111 (available at: https://www.acer.europa.eu/sites/default/files/documents/Publications_annex/2025-ACER-Electricity-Network-Tariff-Annex-I.pdf). Although, in that report, ACER notes that, in certain Member States, including the Kingdom of Belgium, Ireland and the Slovak Republic, non-network costs are bundled into network tariffs and are not clearly separated in the bill, that observation does not appear to apply to the whole of Belgium, but is limited to the Brussels region. See, in that regard, the ACER report, p. 29, paragraph 85, and Table 59 of Annex 1 thereto, p. 111.
42      The Commission considers that the first question referred for a preliminary ruling must be understood as seeking to determine whether a national legislature is competent to adopt provisions requiring a national regulatory authority to take into account, when determining tariffs, costs associated with PSOs. In its view, national regulatory measures which include detailed provisions specifically establishing the factors which are at the discretion of the national regulatory authority, such as tariff levels of the electricity system or the specific methods for calculating them, cannot be permitted in the light of Article 57(4) and (5) and Article 59(1)(a) of Directive 2019/944.
43      See, to that effect, judgment of 2 September 2021, Commission v Germany (Transposition of Directives 2009/72 and 2009/73) (C‑718/18, EU:C:2021:662, paragraphs 108 and 109 and the case-law cited).
44      See judgment of 6 March 2025, Alajärven Sähkö and Others (C‑48/23, ‘the judgment in Alajärven Sähkö and Others’, EU:C:2025:144, paragraph 30 and the case-law cited).
45      See judgment in Alajärven Sähkö and Others, (paragraphs 32 and 39 and the case-law cited).
46      In fact, charges relating to PSOs are akin to a ‘traditional’ support scheme, which Member States use, among other instruments, in the context of State aid schemes for renewable energy.
47      As established in points 50 and 56 of this Opinion, the costs relating to PSOs supporting the promotion of renewable energy fall, in principle, within the latter category.
48      I would point out in that regard that, in the context of the present case, the Energy Decree provides that the passing on of costs by network operators must take place under the supervision of the VREG. According to the written and oral observations submitted by the VREG and the Belgian Government, the control exercised by the VREG covers inter alia verifying the link between those costs and the PSOs and their reasonableness.
49      In particular, that may the case where those aspects include technical
elements which require complex assessments.
50      See judgment in Alajärven Sähkö and Others
(paragraph 40). See, also, my Opinion in that case (C‑48/23, EU:C:2024:695, points 52 and 53).
51      Directive of the European Parliament and of the Council of 13 July 2009 concerning common rules for the internal market in natural gas and repealing Directive 2003/55/EC (OJ 2009 L 211, p. 94).
52      The provision corresponds, expressis verbis, to Article 9(1) to (3) of Directive 2019/944.
53      See judgment of 30 April 2020, Оvergas Mrezhi and Balgarska gazova asotsiatsia (C‑5/19, EU:C:2020:343, paragraph 88). See, also, judgment of 16 July 2020, Commission v Hungary (Charges for access to electricity and natural gas transmission networks), C‑771/18, EU:C:2020:584, paragraphs 47 to 53).
54      Since Regulation 2019/943 does not lay down more specific provisions regarding the applicable methodology for assessing and promoting efficiency, the determination of such a methodology falls within the remit of the national regulatory authority, in accordance with Article 59 of Directive 2019/944.
55      See, by analogy, judgment of 23 October 2025, Gaso and Conexus Baltic Grid (C‑87/24, EU:C:2025:826, paragraph 81). See, also, my Opinion in that case (C‑87/24, EU:C:2025:249, point 65).
56      That is the case in particular where a national regulatory authority is called upon to carry out prospective economic analyses seeking to determine the likelihood of certain developments in the relevant market within a foreseeable time frame. It goes without saying that such prospective analyses are, more often, complex and are necessarily more uncertain than ex post analyses. See by analogy, in the field of mergers, judgment of 13 July 2023, Commission v CK Telecoms UK Investments (C‑376/20P, EU:C:2023:561, paragraphs 82 and 83).
57      It should be noted that most national regulatory authorities in the European Union, when regulating DSO revenues, use historical cost-based methodologies in order to determine their network tariffs. See, in that regard, the Council of European Energy Regulators (CEER) 2023 report, entitled
‘Report on Regulatory Frameworks for European Energy Networks 2023’, of 21 February 2024, available at: https://www.ceer.eu/wp-content/uploads/2024/04/RFR23-Main-report.pdf, in particular p. 166.
58      It should be noted, in that regard, that Article 18(4)(b) of Regulation 2019/943 provides that, when setting the charges for network access, ‘payments expected for future periods, estimated on the basis of previous periods’ is
one of the factors to be taken into account.
59      It is apparent from the order for reference that the tariff methodology adopted by the VREG provides, inter alia, for the VREG to review the reasonableness of the costs declared by the DSOs (consisting, inter alia, of verifying whether the costs are justified from the point of view of distribution system users or the public interest and whether they could have been avoided). Moreover, the VREG applies a revenue cap on endogenous costs, which thus acts as an efficiency incentive. See, also, point 17 of the present Opinion.
60      The referring court notes, in particular, that the methodology applied by the VREG does not appear to include a mechanism for verifying the justification for and necessity of the costs incurred by the DSOs during the reference period. Assuming that the Flemish DSOs in this case were inefficient – a point on which the referring court itself admits that it cannot give a ruling at this stage – that tariff methodology does not, in that court’s view, appear to be capable of detecting such a situation or of preventing excessive costs from being passed on to end users through excessively high tariffs. For the sake of completeness, I would point out that, according to the order for reference, and although they do not, in principle, object to the use of historical costs as a starting point for calculating tariffs, the applicant DSOs dispute the methodology adopted by the VREG on the ground that it risks not ‘overestimating’ their costs as envisaged by the same court, but rather ‘underestimating’ their actual costs (which would consequently result in those DSOs being granted an income that is too low).
The applicant DSOs also emphasise that the historical data on which the method adopted by the VREG is based do not necessarily reflect the actual costs incurred, in particular, in the event of shocks or unforeseeable events resulting in significant fluctuations on the markets.