Greece: 12 GW+ of merchant batteries wait for the green light as curtailments escalate

A year ago, Greece launched a new battery storage program targeting 4.7 GW of utility-scale, standalone projects to be given priority grid connections and operated on a merchant basis, without subsidy support.

Of this capacity, 3.8 GW will connect to the transmission network and 900 MW will be installed on the distribution network. Investors were required to submit their grid connection applications to the relevant operators by the end of October 2025.

Greece’s transmission system operator has since reported receiving applications for around 10 GW of battery capacity, while the distribution system operator received applications totalling 2.15 GW, bringing the combined total to 12.15 GW.

A committee comprising representatives from Greece’s ministry of environment and energy and the two network operators will rank the applications. Despoina Paliarouta, secretary general for energy and mineral resources at the energy ministry, told a recent seminar in the city of Thessaloniki, hosted by Pospief, the Greek association of solar producers, that the energy minister has signed the decision to establish this committee and that the ranking of all 12.15 GW of applications is now imminent.

Financing and ranking hurdles

Storage investors are grappling with two issues. The first concerns the ranking criteria. Applications for projects connecting to the distribution network will be ranked on a first-come, first-served basis, provided they meet all technical standards. For projects connecting to the transmission network, priority will be given to those located closest to substations — but this guidance leaves room for interpretation. It is unclear, for example, whether the nature of the terrain between a storage facility and its nearest substation is a factor. There is also the question of applicants who have proposed connections to substations that are not currently available.

The second issue is project financing. Greece has legislated an energy storage framework, but many policy details remain undefined, adding operational risk. For instance, the law does not currently permit aggregators to represent storage facilities in energy markets.

Grid connection terms will also be critical for lenders. Banks need clear business models, and these depend heavily on connection conditions — such as whether limitations will be placed on how and when batteries can charge and discharge.

Slow start

Banks also lack local reference projects for anchoring risk assessments. Greece ran its first battery storage auction in 2023, awarding subsidies to 12 projects totalling 412 MW of capacity. These projects should have been operational a long time ago, but they are still not connected to the grid; a clear sign that Greece is struggling to connect batteries as previously discussed on ESS News.

Testing is currently under way to connect some of these subsidized projects, but the broader sense among storage stakeholders is that Greek institutions, including the energy ministry, the market operator and the grid operators, have been slow to develop the expertise and coordination needed to integrate these systems. Banks, who share this lack of experience with the Greek storage market, are reluctant to finance merchant projects that do not carry the guarantees that come with subsidised contracts.

Curtailment pressure mounts

Greek PV producers argue that unless meaningful capacities of energy storage projects become operational soon, the country’s escalating green power curtailments will push thousands of small solar PV investors into bankruptcy.

Greece curtailed about 2 TWh of green power in 2025, up from 900 GWh in 2024. Pospief President Giannis Panagis said that in January and February this year, Greece curtailed 184 GWh of renewables compared to just 3 GWh in the same period last year.