In the first half of 2026, clean electricity generation (RES & large hydro) reached a record high of 18,791 GWh. It exceeded the production from the three fossil fuels combined by 5,709 GWh, despite the fact that 9.6% (1,601 GWh) of total RES generation was curtailed. From April -when they started operation- to June, batteries prevented only 2.2% of the curtailments, while they reduced gas production by just 0.6%. Fossil gas remained at high levels with 10,706 GWh and only 195 GWh lower production than the 2025 record, while net exports increased almost sevenfold compared to the first half of 2025. The average monthly DAM price slightly increased in June (+4.4% compared to May) to €92.9/MWh.
This analysis concerns electricity production across the entire territory of Greece and is based on the latest available monthly data from the Independent Power Transmission Operator (IPTO) for the interconnected grid (June 2026) and from the Hellenic Electricity Distribution Network Operator (HEDNO) for the non-interconnected islands (April 2026). In addition, we use data from HEDNO for low and medium voltage, as well as for the installed capacity of self-production systems (April 2026). Data from the Renewable Energy Special Account bulletin of the Renewable Energy Sources & Guarantees of Origin Operator (DAPEEP) (April 2026) are used to calculate more accurately CHP production at low and medium voltage, as well as for the PV utilization factors needed to estimate self-production. Finally, for the wholesale electricity market, we use data from the Day-Ahead Market from ENTSO-E. You can read in more detail about our methodology here.
June
In June 2026, renewables excluding large hydropower plants but including self-production increased by 8.1% compared to May, recording the second highest monthly electricity production in history, with 2,910 GWh, behind only August 2025 (2,948 GWh). Compared to last June, RES increased by 15.9%.
Fossil gas remained in second place with 1,869.1 GWh and an increase of 22.9% compared to the previous month. Compared to June 2025, though, fossil gas decreased by 7.9%.
In third place were large hydropower plants with 415.5 GWh and the highest electricity production for the month of June in the last 13 years. Compared to May, the output of large hydro decreased by 11.6%, while compared to June last year, it increased by 18.2%.
Fourth place was recorded to the output of oil-fired plants for the non-interconnected islands with 224.6 GWh, which increased by 16.8% compared to May, but decreased by 35% compared to June 2025. This decrease is mainly due to the reduced needs of Crete, the electrical interconnection of which was completed at the end of 2025.
In last place was lignite with 129.4 GWh, a quantity that came entirely from Ptolemaida 5, the only lignite unit that remains in operation. Compared to the previous month, lignite electricity generation decreased by 37.4%. However, compared to June 2025 (66 GWh), it was almost doubled.
Finally, large-scale storage systems absorbed a total of 16.4 GWh, while they injected 14.2 GWh to the system, increased by 71.8% and 77%, respectively, compared to May.
Total domestic demand in June was 4,829.3 GWh, increased by 15% compared to May but decreased by 5% compared to June 2025. Total domestic electricity generation was 5,563.4 GWh, increased by 9.3% compared to the previous month and by 4.9% compared to last year.
In the interconnection balance, the country was a net exporter of 734.1 GWh, 17.5% less compared to May, but more than three times higher than those of June 2025.
The average price on the wholesale energy market (day-ahead market) in June was 92.9 €/MWh, up 4.4% compared to the average price in May. It is also noteworthy that the highest price for the year so far (519.3 €/MWh), was recorded on June 30 at 9 p.m.
Comparison with previous years – first six months of the year
Cumulatively for the first six months of 2026, renewables had the highest output with 15,043 GWh, marking a historic high.
However, fossil gas remained in second place with 10,706 GWh, with the second, historically, highest electricity production for this period of the year, just 195 GWh less than last year’s historic high (10,901 GWh).
Large hydroelectric plants were in third place with 3,747.6 GWh, the highest production in a six-month period since 2013 (3,755 GWh).
Lignite followed with 1,405.6 GWh, a historic low, while oil with 970.2 GWh fell below 1 TWh for the first time for this period of the year, marking a historic low.
The injection from storage systems reached a cumulative 25.2 GWh after three months of operation.
For the first half of 2026, domestic demand reached 26,663.7 GWh, showing a decrease of 1.3% compared to 2025. However, domestic electricity production reached 31,907.3 GWh, showing a significant increase of 14.8% compared to the same period in 2025.
In the interconnection balance, the country recorded record net exports with 5,243.6 GWh, 74.1% more than the total net exports of the whole of 2025.
Source changes in demand coverage
Comparing the first half of 2026 with the first half of 2025, it is observed that the three fossil fuels (lignite, fossil gas, oil) decreased by a total of 808 GWh, with the largest decrease coming from oil (-606 GWh) due to the completion of the Crete interconnection. This quantity was more than covered by the increase in renewables (+2,606 GWh), which, for the first time in 2026, exceeded the corresponding increase in large hydroelectric plants (+2,285 GWh). Thus, the largest part of the increase in clean energy, combined with the drop in demand by 353 GWh in the first half of 2026, offset the jump in net exports to neighboring countries (4,461 GWh), which increased almost sevenfold compared to the same period in 2025.
Regarding renewables, the increase during this period of the year seems to be due to both wind and photovoltaics. Data specifically for high voltage show that wind generation reached 6,198.7 GWh (+30% compared to 2025), while photovoltaic generation reached 2,616.4 GWh (+39.5% compared to 2025).
The corresponding percentage changes in the first half of 2026, compared to the first half of 2025 were:
Lignite: -0.5%
Fossil gas: -1.8%
Oil: -38.5%
RES: +21%
Large hydro: +156.2%
Net exports: +569.7%
Domestic demand: -1.3%
Comparison of clean energy with fossil fuels
In the first six months of 2026, clean energy sources (wind, photovoltaic, biomass, self-production and hydro) with a total production of 18,791 GWh reached a historic high. Thus, they exceeded by 5,709.2 GWh the total production from fossil fuels (lignite, gas, oil) which was limited to 13,082 GWh, mainly due to the interconnection of Crete. However, despite the progress, production from fossil fuels in the first half of 2026 remained significantly higher than the historic low of 2023 (10,337.8 GWh).
Compared to the corresponding period in 2025, clean energy sources exhibited an increase of 35.2%, while fossil fuels, on the contrary, decreased by 5.8%. Thus, clean energy overturned the 2025 picture for the first half of the year, taking first place in covering domestic demand with a 70.5% share, and in electricity generation with a 58.9% share.
Renewables Curtailments
Based on the combination of forecasts shown in IPTO’s integrated scheduling process (ISP2 & ISP3), RES curtailments in June are estimated at 298.3 GWh (or 9.3% of total RES generation). This quantity represents a reduction of 28.7% compared to May (418.3 GWh), and 15.2% compared to June 2025 (351.7 GWh). Cumulatively for the first half of the year, total curtailments are estimated at 1,601 GWh (9.6% of total RES generation), a 20.7% increase compared to the same period of 2025. The day with the highest curtailments was Saturday, June 13, 2026, with 37.6 GWh (13% of total curtailments for the month). Most curtailments in June occurred between 9 am and 3 pm.
Battery Storage
Another battery was added to the first nine batteries in the system at the end of June, resulting in a total installed absorption capacity of 540 MW and injection capacity of 531.3 MW. According to forecasts shown in IPTO’s integrated scheduling process (ISP2 & ISP3), the batteries in June absorbed energy mainly between 08.00 – 15.00 and secondarily between 01.00-04.00, while they delivered energy primarily between 16.00-01.00 and secondarily between 05.00-07.00.
In total for the month of June, the batteries absorbed 16.4 GWh and injected 14.8 GWh to the system[1]. However, the same forecasts show that absorptions of 2.5 GWh occurred during hours when there were no RES curtailments. Given that the total curtailments in June were estimated to be 298.3 GWh, it follows that the absorption of 16.4 GWh of installed batteries prevented 4.5% of the RES cuts, while the injection of 14.8 GWh limited gas use by only 0.8% in the same month.
Cumulatively from April 2026, when the first two batteries were set into operation, until June, the batteries absorbed 30.7 GWh, of which 4 GWh in hours without RES cuts, while they contributed 27.1 GWh to the system. Therefore, they prevented just 2.2% of the total RES curtailments in this period (1,191.4 GWh), while limiting gas-fired electricity generation by only 0.57% (10,706 GWh).
These figures highlight the need to accelerate the deployment of more batteries in order to prevent more curtailments and reduce gas use during evening peaks to a much greater extent. Accelerating the deployment of storage systems was also the subject of the tripartite agreement signed at the EU Energy Council on 26 June 2026, highlighting the need to install 200 GW of storage systems by 2030 to support the energy system[2].
Hours with near-zero or negative DAM prices
Regarding hours with near-zero[3] or negative prices in the wholesale electricity market, June 2026 recorded 146.5 such hours, 71.5 hours less than the previous month but 102.5 hours more than June 2025. In total, in the first half of 2026, 788 hours with near-zero or negative prices were recorded, approximately 4.7 times more than the 168 such hours that occurred in the same period in 2025.
[1] According to the data in the IPTO monthly bulletin for the month of June, the batteries absorbed 16.4 GWh while they delivered 14.2 GWh to the system, quantities similar to those of IPTO’s daily ISP2 & ISP3 forecasts (16.4 GWh and 14.8 GWh, respectively).
[2] First-ever EU tripartite agreement signed to boost energy storage: https://ec.europa.eu/commission/presscorner/detail/en/ip_26_1426
[3] DAM prices lower than 0.05 €/MWh.
