The Green Tank estimated renewable-energy curtailment in Greece at 158.2 GWh in September 2026 and 2.063 TWh in the first nine months of the year. That was 7.8% of potential renewable generation and 15.6% above the same period of 2025.
Surplus generation is increasingly occurring when demand, exports and storage cannot absorb the electricity. The pressure is making storage and shaped power contracts more important to financing new photovoltaic investment across Southeast Europe, where managing delivery timing is becoming central to project financing.
ACER highlighted the effect on solar revenues: in May 2026, Greek solar power had a capture price of €24.63/MWh, compared with an average wholesale price of €88.95/MWh. A first-half 2026 analysis put the average solar capture rate at 44%, down from 61.6% in the first half of 2025 and 71.9% in the first half of 2024.
The declining capture rate reflects solar cannibalisation: additional photovoltaic plants tend to generate at the same hours as the existing fleet, adding renewable output while lowering the price received for each solar megawatt-hour. High evening prices do not compensate a merchant solar plant unless it can shift energy to those hours or use a contract that transfers the shape risk.
Around 800 MW of storage was connected in Greece by autumn 2026. System analysis indicates that batteries are already reducing renewable-energy curtailment and gas use.
ACER’s broader analysis of power purchase agreements found that renewable-plus-storage structures can materially increase capture rates by shifting output to higher-value hours and giving buyers a more stable profile.
Lower winter irradiation is expected to ease midday oversupply while also reducing solar generation. Output is expected to recover from late in the first quarter of 2027, when pressure on capture prices could strengthen again.
