Greece struggles to connect battery storage projects

In 2023, Greece ran its first battery storage auction, awarding 412 MW across 12 projects. In 2024, it ran a second tender awarding 300 MW of additional battery storage capacity across 11 projects, while in 2025 it also awarded 189 MW of battery storage via a third tender.

Of this capacity, there is not even a single MW that has been connected to the grid. Stelios Psomas, policy officer at the Hellenic Association of Photovoltaic Companies (Helapco), told a recent webinar organised by renewable energy developer BayWa r.e. Greece, that about 300 MW of tendered projects have indeed been installed but are still awaiting for grid connection.

It is not clear why these projects remain unconnected to the grid. Moreover, according to the procurement rules, projects awarded in the first two auctions should be operational by the end of 2025.

Speaking to ESS News, some investors blamed relevant institutions for this delay, citing unclear energy market structure and slow response to the investors’ requests. Other investors, though, told ESS News that most of the successful bidders offered lower prices than they could afford to develop their projects and therefore were slow in building them.

Nevertheless, the bottom line is that Greece needs urgently to install and connect energy storage capacity to the gird. Psomas told BayWa r.e.’s webinar that the country needs about 8 GW of energy storage to limit renewable energy curtailments down to acceptable levels and keep up with the domestic green energy boom. There are policy programs stimulate energy storage development in Greece, however the pivotal question is how fast this capacity can be installed, he said.

Petros Tsikouras, organizational secretary of POSPIEF, a Thessaloniki-based association of Greek solar producers, told ESS News that “Greece curtailed about 1.85 TWh of renewable power in 2025. Of this, the biggest amount corresponds to solar energy since curtailments occur predominantly from 9 a.m. and 4 p.m., which is the time solar farms generate power. Curtailment of renewable energy this year increased tenfold compared to last year, while in 2026 Greece might need to curtail 20 times more green power than it did in 2024.”

Energy storage developers in Greece have now turned their attention to the country’s 4.7 GW program for the development of utility-scale, standalone projects which will be given a priority connection and operated on a merchant basis without subsidy support. Investors had to submit their application for grid connection by the end of October and are now waiting for the Greek energy ministry and the grid operators to rank their applications.