Greece is offering Southeast Europe a clear example of how rapid solar photovoltaic expansion can erode renewable revenues, even as solar generation remains strategically valuable to the electricity system. The pressure comes not from solar production itself, but from increasing volumes of generation arriving in the same hours.
Curtailment and low-price hours increase
Renewable curtailment in Greece totalled 1,601.4 GWh in the first half of 2026. That was up from 1,327.1 GWh in the same period of 2025 and 513.5 GWh two years earlier. Greece also recorded 788 hours of near-zero or negative wholesale prices in H1 2026, compared with 168 hours in H1 2025 and 135 hours in H1 2024.
The impact on photovoltaic economics is reflected in the solar capture rate. The average rate fell from 71.9% in H1 2024 to 61.6% in H1 2025 and 44.0% in H1 2026. In May 2026, solar generation captured a value equal to just 28.3% of the average wholesale price.
A photovoltaic plant can generate exactly as its technical model predicts and still deliver revenue well below its original assumptions. When many solar installations produce at the same time, additional daytime supply pushes down the market price. As installed capacity grows, new projects can also reduce the value captured by existing generators.
Limited grid capacity to transport available generation adds curtailment to the pressure on revenues. By August, Greece had recorded 949 hours of near-zero or negative prices in the first eight months of 2026, around three times the level for the corresponding period of 2025.
Revenue effects reach existing assets
Greece provides an early indication of the risks that can arise when renewable deployment advances faster than transmission investment, storage, flexible consumption and other forms of system flexibility. The effects are not confined to new projects: existing photovoltaic assets financed using older assumptions may also need reassessment.
One consideration is revenue. A lower expected captured price means merchant projects generate less cash, even if annual wholesale prices remain relatively strong. Another is curtailment: each curtailed MWh is technically available production that cannot be monetised unless contractual or regulatory compensation applies.
Valuation is also affected. Assets bought on the basis of historical capture rates may command different values when future revenue models account for stronger cannibalisation. Lower expected cash flows can also reduce the debt an asset can support, even when the plant remains technically sound and operationally profitable.
AleaSoft distinguishes asset profitability from compliance with financing requirements. A project may still be able to service scheduled debt but fall short of the coverage levels set in its financing agreements.
Operating strategies and regional implications
For operating Greek assets, the response need not be to abandon solar, but to reconsider how the asset earns revenue. Potential measures 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.
Investors in neighbouring markets have reason to watch Greece, although Serbia, Bulgaria, Romania, Croatia, Montenegro and other regional systems will not necessarily follow the same path or timetable. Their generation mixes, interconnection capacity, support mechanisms and market structures differ. Greece’s experience nevertheless demonstrates the risk of assessing renewable build-out solely in MW.
Once solar reaches sufficient scale, another measure becomes essential: the share of the market’s headline electricity price that photovoltaic generators actually capture. For Southeast European investors, Greece has made that project-finance issue observable in the market.