In March, Greece recorded 200 gigawatt-hours (GWh) of renewable energy curtailment, a figure that represents one-fourth of the total curtailment accumulated during 2024. This data, revealed by Giannis Margaris, Vice President of the Independent Power Transmission Operator (IPTO) of Greece, during the “Power & Gas Forum 2025”, set off alarms across a sector that sees the deployment of new clean capacity at risk unless current bottlenecks are resolved.

The issue is structural rather than circumstantial: the grid lacks the capacity to absorb the increasing renewable generation, especially during peak solar production hours. On Sunday, March 2 and March 23, curtailments exceeded 17 GWh on each day.

According to updated figures, 900 GWh of clean energy have been curtailed in the past 12 months, a number that continues to rise monthly and directly impacts the profitability of operating projects. These losses accounted for 3.3% of total renewable energy production in Greece, and the sector expects the figure to reach new highs this year.

Rising frustration in the industry over lack of corrective measures

In response to the increasing volume of curtailments, the Greek Government introduced a draft bill to regulate renewable energy spillage.

Earlier this month, the Ministry of Environment and Energy (YPEN) held a meeting with the Regulatory Authority for Waste, Energy and Water (RAAEY), the Independent Power Transmission Operator (IPTO), and renewable energy aggregators to develop a new methodology to tackle the issue. The discussion was especially relevant with the arrival of spring—when solar and wind production rises while demand drops—and ahead of the Easter holidays (April 18 to 21), a period traditionally marked by a sharp decrease in electricity consumption.

The bill received feedback from the Hellenic Wind Energy Association (HWEA or ELETAEN) and other organizations regarding its provisions on curtailments. HWEA stated that operators should only be exempt from compensation if a framework is in place to reimburse larger producers. This would mean that any revenues collected through penalties should be used to compensate other producers.

HWEA also emphasized that, under European legislation, compensation is mandatory and must be included in the regulatory framework.

A grid lagging behind

The most critical bottleneck in Greece’s renewable energy sector remains grid infrastructure. The Vice President of IPTO acknowledged that the operator is working to reinforce interconnections and increase the grid’s absorption capacity. However, these technical improvements require time and major investment, leaving the sector vulnerable to increased curtailments in the short term.

One of the solutions under consideration is to make grid access contracts more flexible, allowing projects to offer services beyond just energy injection. Demand response technologies and smart generation management systems are also being considered.

IPTO aims to provide connection conditions for 28 GW to 30 GW of renewable energy sources by 2030. Out of this total, 20 GW will be allocated to solar PV. However, there are over 70 GW of competing grid connection applications, according to the Hellenic Association of Photovoltaic Companies (HELAPCO).

Urgency to accelerate storage deployment

In this context, energy storage emerges as a key solution. According to Greece’s National Energy and Climate Plan (NECP), the country aims to install 4.3 GW of storage by 2030, although the solar PV sector is demanding an increase to 8 GW to avoid operational collapse in the coming years and to keep energy spillage levels below 2%.

Studies conducted in Greece show that for every 1 GW of standalone battery energy storage systems (BESS), energy curtailment can be reduced by between 0.62 and 1.18 TWh, depending on capacity.

To reduce these energy losses and improve system stability, Greece has implemented a new regulatory framework for granting final connection offers to independent energy storage plants (Σ.Α.Η.Ε.).

The regulation sets a maximum capacity of 4,700 MW for new storage facilities, though experts warn this may not be sufficient to absorb all excess renewable generation. Of this capacity, 3.8 GW will be for transmission-connected systems, and 900 MW for distribution-connected systems.

It is worth noting that the Greek Government recently published the results of the third storage auction, awarding 189 MW at average bid prices of €52,589/MW/year.

Pressure mounts on the Government

The Greek renewable sector is calling for more aggressive policy measures. According to solar associations, the only way to maintain installation rates and meet climate goals is to prevent the grid from becoming a structural barrier.

Key demands from the sector include:

• Increasing the pace of storage auctions

• Accelerating grid infrastructure projects

• Implementing compensation mechanisms for curtailed energy

The Greek energy transition is not slowing down—but the electrical system must evolve in step with renewable investments. Otherwise, the risk is not only technical, but also financial.