Continuous negative and zero wholesale electricity prices, weak demand, and Greece’s inadequate energy storage policy are leaving small- and medium-sized PV investors exposed, despite abundant solar resources.
Image: pv magazine/AI generated
Wholesale electricity prices in Greece between 8 a.m. and 6 p.m., when solar irradiation is highest and photovoltaic systems generate most output, have collapsed, frequently reaching zero or negative levels.
At the same time, significant volumes of renewable generation are being curtailed during these hours. Preliminary data from the Greek energy regulator show that 876.5 GWh of renewable energy was curtailed between January and April this year, up from 588.5 GWh in the same period a year earlier. In the whole of 2024, total curtailment reached around 900 GWh.
“This situation is the new normal,” Petros Tsikouras, organizational secretary of POSPIEF, a Thessaloniki-based association of Greek solar producers, told pv magazine. He added that in March, small PV parks lost 62% of revenue, rising to 70% in April. “7,500 small producers — the backbone of the country’s decentralized energy system — are being pushed within months into financial suffocation,” he said.
Tsikouras warned that many investors may soon be unable to service debt, leading either to bankruptcies or forced asset sales and market exits.
The Hellenic Association of Photovoltaic Energy Producers (Spef), which is one of Greece’s other main photovoltaic associations, had asked the government already in 2024 to stop issuing new grid connection licenses for renewable energy systems to address the nation’s escalating power curtailment issue.
Konstantinos Tsirekis, director of the Strategy and System Planning Department at Greece’s transmission system operator, said at a recent POSPIEF event that Greece had installed 17.9 GW of renewable capacity by the end of February. Of this, 11.7 GW comes from solar PV, 5.6 GW from wind, and 0.6 GW from other renewables such as small hydro plants. Large hydro capacity was not included in these figures.
He added that around 14.1 GW of renewables have already received connection offers to the transmission and distribution networks, while a further 48 GW have applied for grid connection at transmission level and are still under review. Greece’s peak electricity demand, meanwhile, stands at around 11 GW.
At the same event, Pantelis Biskas, professor at the Aristotle University of Thessaloniki’s Department of Electrical and Computer Engineering, noted that electricity demand in Greece has remained broadly flat despite the country’s recovery from its recent economic crisis. Annual consumption is stable at around 50–51 TWh, a level he does not expect to change significantly in the coming years.
Biskas said Greece exported about 3 TWh of electricity last year, enabled by low-cost domestic renewable generation. However, he stressed that this remains marginal compared to total annual demand and does not materially alter the overall consumption outlook.
Tsikouras argued that the current imbalance is the result of policy decisions. “Over the past six years, the government pushed for massive over-licensing of renewable energy projects – up to 25 GW – in a system that consumes between 4 and 11 GW daily,” he said. He also criticized delays in establishing a functioning energy storage framework, saying these have undermined market stability.
Greece held its first battery storage auction in 2023, awarding 412 MW of capacity across 12 projects with significant subsidy support. Investors participated despite uncertainty over future market design, while the regulatory framework for battery operation was expected to be completed in the following two years, with operational deadlines set for 2025.
However, implementation lagged behind schedule. According to industry participants, regulatory delays left approved projects without a clear route to market participation. Some battery installations reached readiness by December 2025 but were unable to connect to the grid due to the absence of finalized operational rules. Authorities have cited the novelty of the technology and limited prior experience, though critics argue that sufficient time was available to prepare the framework.
Nevertheless, of the 412 MW of storage capacity awarded in the 2023 auctions, only two projects totalling around 16 MW have begun participating in Greece’s electricity markets as of April. The system operator has said that roughly 200 MW of additional stand-alone battery projects are now connected to the grid and undergoing testing ahead of imminent market participation. However, there is still no clear timeline for when these projects, or the remaining awarded capacity, will become fully operational in the market.
Tsikouras argues that the situation goes beyond administrative delay. “This is not only incompetence. It is politics,” he said. He described a system in which electricity is increasingly generated when it is not needed, while a lack of storage prevents shifting that energy to peak hours. “This creates winners and losers. Small- and medium-sized investors are the biggest losers, while a few energy companies that can generate power in the evening are the winners.”
He noted that in the evening hours—around 19:00 to 22:00—solar generation drops to zero, leaving gas-fired plants and large hydro units to set prices, which can spike to €170–€250 ($200-$294)/MWh. “This is why the government has been delaying energy storage for years,” he said.
All photovoltaic installations selling into wholesale markets are exposed to curtailment and periods of zero or negative prices, though larger operators are generally better equipped to manage volatility through advanced trading strategies. Revenue exposure also depends on the remuneration model: subsidy-free plants selling directly into the day-ahead market can benefit from high price spikes when they occur, while smaller installations under fixed or premium tariffs cannot fully capture upside volatility. In the case of contracts for difference (CfDs), any revenue above the strike price must be repaid, further limiting gains from price spikes.