Curtailments and negative prices reduce solar power revenue in Greece by as much as 60%.

Solar parks in Greece that utilize the primary state support system experienced an average revenue decline of 50% year-over-year in April. Due to insufficient energy storage, instances of zero and negative electricity prices are becoming more common and lasting longer, along with curtailments that disproportionately impact facilities connected to the high-voltage grid. Some companies reported losses reaching 60%, with expectations that May may be even more challenging.

Revenue losses from photovoltaic plants hit unprecedented levels last month, according to Energypress. The report highlighted those benefiting from the Greek Operating Aid Contract for Difference, referred to as SEDP. This scheme operates as a two-way contract-for-difference model, providing a sliding or floating feed-in premium based on wholesale power prices.

On average, solar parks in the over 400 kW category experienced a remarkable 50% decline last month compared to April 2025. As the rollout of battery energy storage systems (BESS) continues to lag behind solar power growth, the day-ahead market increasingly shows zero or negative prices.

Furthermore, solar production at midday, especially during weekends and holidays when electricity demand is lower, often leads to grid overload. This situation forces system operators to reduce output from some of the PV fleet.

Loss rates doubled from March.

The impact of these measures is felt more by the larger units connected to the transmission system than by those on the distribution level. Some companies reported losses as high as 60% in April when compared to theoretical revenue that would exclude zero and negative prices and production restrictions.

Significantly, the average year-over-year loss was twice as high in percentage terms compared to March. The current month does not appear promising—zero and negative prices have been recorded almost daily since the start of May, persisting for at least four hours each time.

In contrast, neighboring Bulgaria, which has the highest battery storage capacity in Europe, is importing electricity during the day and reselling it at peak evening prices.

Concerns about an avalanche of non-performing loans are rising. Evangelos Mytilineos, Executive Chairman of Metlen Energy and Metals, anticipates that banks will begin seizing assets in the solar power sector.

Aktor Group's Chairman and CEO, Alexandros Exarchos, has warned about a significant risk of destabilization in Greece's renewable electricity market. He directly associates the increasing curtailments with the potential for non-performing loans that could amount to EUR 25 billion.