Greece’s solar curtailment starts to bite

Greece’s transmission system operator, IPTO, said that it had to halt electricity imports from neighboring countries from May 3 to May 7 to ensure the safe operation of the Greek electricity system. Specifically, IPTO said during this period that it did not import any electricity at all from Italy, Albania, North Macedonia and Turkey.

With regards to the electricity interconnection to Bulgaria, IPTO allowed no electricity import from 9 a.m. to 4 p.m. on those days and imposed caps at other times.

Separately, market sources told pv magazine that on May 5, IPTO disconnected the entire renewable-energy fleet connected to the transmission lines for a number of hours. It also asked the Greek distribution operator, HEDNO, to disconnect an additional 1 GW of solar plants. The reason behind this was very low electricity demand when Greece celebrated the Orthodox Easter on May 5.

Renewable power curtailment for the remainder of the Easter holiday period, lasting from May 3 to May 7, were also very high. But Easter holiday curtailment did not come as a surprise. In April, Pantelis Biskas – a professor at Greece’s Aristotle University of Thessaloniki, Department of Electrical and Computing Engineering – warned the annual assembly of the Thessaloniki-based Pospief association of solar producers in mid-April that curtailment would skyrocket on Easter, as well as from September to November.

Biskas told investors that from March 1 to April 13, IPTO had planned to curtail 220 GWh of renewable energy, corresponding to about 4% of the nation's domestic green electricity production for this period. This level of curtailment might sound low for some, but for Greece’s PV producers, this is in stark contrast to previous years. In 2023, for example, Greece curtailed a total of about 228 GWh.

Even more worrying was Biskas’ prediction that curtailment of renewable power in Greece might reach up to 15% of the country’s electricity generation in 2030. Participants at Pospief’s assembly also expressed concern about the different curtailment methods used by Greece’s transmission and distribution grid operators.

IPTO is able to vary the amount of generated solar electricity injected in the grid, they claimed, but distribution grid operator HEDNO doesn’t follow the same pattern. HEDNO will either allow solar parks to be plugged into the network, or totally cut it off from the distribution grid. Given that a lot of solar projects connect directly to the distribution grid, HEDNO’s patterns affect a large number of PV investors.

This problem is set to be solved soon, though. A new law voted on in the Greek parliament at the end of April requires all renewable energy plants larger than 400 kW to install the technical equipment that allows HEDNO to remotely control the output of solar projects and vary the electricity injected into the distribution grid.

Naturally, the discussion at Pospief’s assembly also shifted toward energy storage. Last year, Greece launched a 1 GW energy storage tender program. It targeted batteries installed in front of the meter. Awarded projects receive public subsidy support. However, Pospief General Secretary Petros Tsikouras told pv magazine that the Greek government’s energy storage policy has moved in the wrong direction.

“It took the government four years to introduce an energy storage framework and when it did, it only allowed in front of the meter subsidized energy storage systems. On the contrary, Pospief is calling the government to open the energy storage market to behind the meter storage systems that get installed without subsidies. There is strong investment appetite in Greece for such systems. The business case is there given that such systems can participate in the country’s balancing services market,” said Tsikouras. “This is where the main issue lies. The government has delayed the energy storage framework in order to allow the gas plants enough time to rip the benefits of the balancing services market. At some point, it will bow to pressure and allow behind the meter energy storage to get built too. Until then, the balancing services market is dominated by gas plants who can flex their production as they like.”