Greece has become Southeast Europe’s clearest example of how rapid growth in photovoltaic capacity can erode renewable revenues, even as solar remains strategically valuable to the electricity system. The issue is not solar generation itself, but the increasing concentration of output in the same hours.
Renewable curtailment in Greece totalled 1,601.4 GWh in the first half of 2026, compared with 1,327.1 GWh in the same period of 2025 and 513.5 GWh two years earlier. Over the same half-year, the country recorded 788 hours of near-zero or negative wholesale prices, up from 168 hours in H1 2025 and 135 hours in H1 2024.
The impact on photovoltaic economics was greater still: the average Greek solar capture rate declined from 71.9% in H1 2024 to 61.6% in H1 2025 and 44.0% in H1 2026. In May 2026, solar generation was valued at only 28.3% of the average wholesale price.
Concentrated output weighs on solar revenues
A photovoltaic plant can perform exactly as its technical model predicted and still fall substantially short of its original revenue assumptions. When many solar installations generate at the same time, added daytime supply pushes market prices down. As installed capacity grows, each new project can help reduce the value captured by existing generators.
Insufficient grid capacity to transport all available generation compounds the effect through curtailment. By August, Greece had recorded 949 hours of near-zero or negative prices in the first eight months of 2026, around three times the figure for the corresponding period of 2025.
This makes Greece an important market for investors elsewhere in Southeast Europe, offering an early view of the effects of renewable deployment outpacing transmission investment, storage, flexible consumption and other forms of system flexibility. The consequences reach beyond new projects, as existing photovoltaic assets financed on older assumptions may also need to be reassessed.
Revenue, curtailment and asset financing
Lower expected capture prices reduce cash generation at merchant projects, even when annual wholesale prices remain relatively strong. Curtailment creates a separate revenue loss: each MWh of technically available generation that is curtailed cannot be monetised unless contractual or regulatory compensation applies.
Asset valuations may also change when projects bought on the basis of historical capture rates are assessed using future revenue models that account for stronger cannibalisation. Lower projected cash flows can reduce the debt an asset can support, even if the plant remains technically sound and operationally profitable.
AleaSoft distinguishes asset profitability from compliance with financing terms. A project may still be able to service scheduled debt while falling below the coverage levels required by its financing agreements.
Operating responses and regional relevance
For operating Greek assets, the response is not necessarily to abandon solar, but to reconsider how the asset earns revenue. Options include renegotiating route-to-market arrangements, changing hedging structures, refinancing debt, adding flexibility or adjusting operating strategies. None removes the underlying market signal: the economic value of electricity increasingly depends on when it is generated.
Neighbouring markets will not necessarily follow Greece’s trajectory or timetable. Serbia, Bulgaria, Romania, Croatia, Montenegro and other regional systems have different generation mixes, interconnection capacity, support mechanisms and market structures.
However, Greece’s experience shows the risk of analysing renewable expansion only in MW. Once solar reaches sufficient scale, investors also need to assess the share of the market’s headline electricity price that photovoltaic generators actually capture. In Southeast Europe, that has made the issue an observable market phenomenon rather than a theoretical project-finance concern.
