The summer trading season is coming to an end. For solar producers and the companies trading renewable generation, the past few months have again provided a concentrated view of how the electricity market behaves when substantial volumes of generation enter the system at the same time. September is therefore a natural point to review the summer and start looking at the next trading period.
For those following the market from a regulatory perspective, however, the summer has provided something else to look at. While much of the industry was taking a break, the European electricity-law agenda continued to develop. Some of the more interesting developments have not come in the form of new market rules, but through cases now before the Court of Justice of the European Union.
These cases are worth following because they concern questions that sit close to the practical boundaries of the internal electricity market: how Member States may intervene in electricity revenues, how alternative electricity supply arrangements should be understood under EU law, and how existing EU electricity-market rules apply when national measures interact with new market realities.
A judgment that puts national intervention in perspective
One of the most relevant judgments of 2026 so far is Secab, Case C-423/23, delivered by the Court of Justice on 22 January 2026. The case concerned an Italian mechanism limiting the market revenues of certain renewable electricity producers during the period of exceptionally high electricity prices.
The case arose in the context of Article 15-bis of Italian Decree-Law No 4/2022 and concerned run-of-river hydroelectric power plants. The Court was asked to clarify the relationship between the Italian measure, Article 5 of Directive (EU) 2019/944 and Articles 6 to 8 of Regulation (EU) 2022/1854, which introduced the temporary EU emergency framework for electricity-market revenues.
The judgment is particularly useful because it draws a line between what the EU emergency regulation required and what it merely allowed Member States to do. For the period from 1 December 2022 to 30 June 2023, Regulation 2022/1854 established a maximum market-revenue cap of EUR 180/MWh for the categories of electricity production covered by Article 7, while Article 8 allowed Member States, subject to specified conditions, to introduce national measures that further limited market revenues.
Importantly, the Court held that EU law did not, in itself, prevent the Italian legislation from applying a lower national cap without guaranteeing that producers retained 10% of the revenues above that cap. The Court also made clear that the mere fact that a national cap was lower than the EUR 180/MWh level in the EU regulation did not automatically make it incompatible with EU law. What mattered was whether the conditions in Article 8(2) were respected, including the requirement that the measure should not jeopardise investment signals and should ensure that investment and operating costs were covered.
The Court also rejected the argument that Italy was required to impose a corresponding cap on electricity produced from hard coal or to differentiate its cap between solar, geothermal and wind generation. The relevant provisions of Regulation 2022/1854 gave Member States options in those respects rather than imposing such obligations.
For renewable generators and investors, the broader significance of Secab is therefore not that revenue intervention is either permitted or prohibited in the abstract. It is that EU law leaves Member States a certain degree of discretion while placing substantive conditions around the way that discretion is exercised. The interaction between national intervention, investment signals and the EU electricity-market framework is likely to remain relevant well beyond the temporary measures that gave rise to the case.
A Latvian case to watch this autumn
A different question is now approaching the Court from the Baltic region.
Joined Cases C-722/24, Elektro bizness, and C-756/24, Jelgavas autobusu parks, concern the interpretation of the concept of a “direct line” under Article 2(41) of Directive (EU) 2019/944.
The cases originated in Latvia and raise questions concerning the circumstances in which an electricity line connecting a generator and a customer can qualify as a direct line. Among the issues before the Court are whether a customer must be completely disconnected from the public electricity network, whether a customer may remain connected to the network while receiving electricity through a direct line, and whether one direct line may connect a generator with several customers.
On 12 February 2026, Advocate General Juliane Kokott delivered her Opinion in the joined cases. Her proposed interpretation is significant because it focuses on the function of the direct line rather than treating connection to the public network as automatically decisive. In particular, the Opinion addresses the possibility that a direct line may exist even where the customer remains connected to the public network, provided that the electricity supplied through the direct line reaches the customer without the intermediation of the public network. The Opinion also addresses the possibility of a direct line serving several customers.
This is, however, an important point at which terminology matters: the Opinion of an Advocate General is not a judgment of the Court. The Court is not bound by the Opinion and will make the final determination.
That makes this case particularly interesting to watch. The question of what constitutes a direct line may appear narrow, but it goes to a broader issue in the internal electricity market: how much room does EU law leave for alternative arrangements between generation and consumption alongside the public network?
The answer could matter for decentralised energy projects, industrial electricity supply arrangements and other models in which the traditional relationship between generator, network and consumer is organised differently. The Court’s judgment is therefore one of the developments worth watching as the autumn begins.
Another question: how far can Member States go?
A third case worth following is Joined Cases C-251/24 and C-392/24, Axpo Energy Romania and PPC Renewables Romania. Here again, the Court has not yet delivered its judgment. Advocate General Athanasios Rantos issued his Opinion on 25 June 2026.
The cases concern Romanian legislation adopted in the context of the energy crisis which established contributions to an energy-transition fund applying to certain electricity and natural-gas market participants, including trading operators and electricity producers. The referring court has raised questions concerning the compatibility of those measures with EU law, including the rules governing the internal electricity market and fundamental principles of the EU legal order.
The Advocate General’s Opinion is therefore another useful example of the legal questions emerging from the energy crisis: when may a Member State impose additional financial obligations on participants in electricity markets, and what limits arise from EU law when those obligations affect the way in which market participants operate?
The case is not a decision on the general legality of taxation in the energy sector, nor does the Advocate General’s Opinion itself determine the final outcome. Its importance for market participants lies in the way it examines the relationship between national crisis measures and the EU framework governing electricity markets.
That distinction is worth keeping in mind as energy markets continue to evolve. The existence of a European internal market does not remove Member States’ ability to regulate or respond to exceptional circumstances. At the same time, national measures remain subject to the requirements of EU law. The boundary between those two principles is often where the most interesting legal questions arise.
Why these cases matter for new market models
Taken together, these developments point to something that is easy to miss when following energy regulation only through newly adopted legislation.
The European electricity market is not being shaped solely by new directives, regulations and policy initiatives. It is also being shaped by the interpretation of the rules that already exist.
That becomes increasingly important as the physical electricity system changes. Storage, distributed generation, flexible demand and other technologies create capabilities that do not always correspond neatly to the traditional categories of electricity-market regulation. The legal framework already contains concepts such as active customers, aggregation and energy communities, but their practical significance depends on how the relevant provisions interact with national rules and with the wider structure of the internal electricity market.
The direct-line proceedings illustrate one side of this development: an existing concept in the Electricity Directive is being tested against questions arising from increasingly decentralised electricity arrangements. Secab illustrates another: an emergency measure adopted in response to exceptional market conditions has to be assessed against an EU framework that itself gives Member States a degree of discretion while imposing conditions on the exercise of that discretion.
For companies developing or operating new energy-market models, this is where regulatory analysis becomes more than a compliance exercise. It becomes part of understanding where commercial opportunities can realistically develop.
Looking beyond the summer
The end of the summer trading season is therefore a useful moment to look in two directions at once. The trading results tell us how today’s market performed; the legal developments tell us something about the boundaries within which tomorrow’s market will operate.
There is no single court judgment that will define the future European electricity market, and none of the cases discussed here does so. Their importance is more incremental. They contribute to the interpretation of the legal framework at precisely the points where technology, market design and national regulation are beginning to meet in new ways.
That is also why the autumn ahead is worth watching. The judgment in the Latvian direct-line cases will provide the Court’s own interpretation of Article 2(41) of Directive 2019/944. Axpo Energy Romania and PPC Renewables Romania remain pending, while the Secab judgment already provides an important reference point for understanding the limits and conditions of national intervention in electricity markets.
For market participants, the practical lesson is straightforward: understanding the electricity market increasingly requires following not only prices, volumes and trading opportunities, but also the legal decisions that determine who can participate, under which conditions and through which structures.
Summer may be over. The next phase of the European electricity market is already being shaped — including in courtrooms.
