In October 2025 carbon intensity in electricity production reached an eight-month peak (266 g CO2/kWh) due to high production from both gas and lignite compared to other months during this period. In the first 10 months of 2025, total emissions reached 12.9 million tons, exceeding the NECP target for the annual carbon budget by 2.7 million tons. Gas-fired units were responsible for 55.5% of the total, setting a 10-month emissions record of 7.16 million tons.
Monthly emissions from each power plant in Greece are estimated based on the latest available electricity production data (October 2025 for the interconnected network and for the non-interconnected islands) and the annual CO2 emissions from ETS (2024), following the methodology and assumptions presented here.
In October 2025, the carbon intensity[1] of electricity production increased by 20.6% compared to September, reaching 266 g CO2/kWh and an eight-month high. This increase is due to an increase in total emissions and a decrease in electricity production. Specifically, emissions in October 2025 reached 1.24 million tons (+10.3% compared to September), while total electricity generation was 4.64 TWh (-8.5% compared to September).
However, for the first ten months of 2025, the average carbon intensity stood at 254 g CO2/kWh, down 6.3% compared to the average carbon intensity in 2024.
The impact of RES curtailments on carbon intensity is notable. Based on IPTO’s ISP2 and ISP3 forecasts, for the period January to October 2025, RES curtailments totaled 1,837 GWh or 7.5% of total RES production. If this energy were used to reduce the use of fossil fuels, carbon intensity would be 234.9 g CO2/kWh, 7.5% lower than the actual intensity.
In October alone, CO2 emissions from lignite plants reached 0.26 million tons, +69% from September and a quarterly high. While lignite plants contributed less than 3% to meet October’s electricity demand, they were responsible for 21% of emissions.
Gas plants emitted 0.71 million tons in October, up 8.5% from the previous month and accounting for 57.6% of total monthly emissions. Emissions from oil plants on non-interconnected islands reached 0.22 million tons, 19.2% less than in September.
Cumulative CO2 emissions for the first ten months of 2025 reached 12.9 million tons, exceeding 2024 emissions for the same period by 3% and just 0.5% below 2023 emissions for the ten-month period. The main reason for this increase was emissions from gas-fired power plants, which reached a historic high.
More specifically, emissions from gas-fired power plants for the first ten months of 2025 totaled 7.16 million tons, marking a record high and an increase of 10.3% compared to the first ten months of 2024. Gas plants were responsible for 55.5% of total emissions from electricity production for the ten-month period.
On the other hand, emissions from lignite plants reached 2.9 million tons for the same period, down 8.5% compared to the same period in 2024, slightly exceeding emissions from oil-fired plants on non-interconnected islands (2.5 million tons), which are also on a downward trend compared to last year (-2.8%). Lignite accounted for 22.2% of emissions in the first ten months, while oil accounted for 19.6%.
Avoiding RES curtailments during this period (1,837 GWh) could lead to significantly lower emissions from electricity production. Specifically, if RES were used instead of fossil fuels, cumulative emissions in 2025 would be 11.9 million tons, or 0.97 million tons less than actual emissions.
In the first ten months of 2025, the lignite-fired power plant of Agios Dimitrios remained at the top of the list of polluters with 2.1 million tons. Despite producing just 1.33 GWh, Agios Dimitrios was responsible for 73.4% of emissions from lignite plants and 16.8% of total emissions from the sector for this period.
Ag. Nikolaos II remained in second place with emissions of 1.1 million tons, while in third place was Lavrio IV-V with emissions of 0.87 million tons. The list of top five polluters was completed by the Megalopolis V gas plant and the Ptolemaida 5 lignite plant, with emissions of 0.82 million tons and 0.74 million tons, respectively.
On the non-interconnected islands, the five largest polluters were two power stations in Crete, the power stations on the island of Rhodes and the station on the island of Kos. Specifically in Crete, Atherinolakkos recorded emissions of 0.56 million tons and Linoperamata 0.36 million tons for the ten-month period of 2025. On the island of Rhodes, the Rhodes plant recorded emissions of 0.27 million tons, while the N.Rhodes plant noted emissions of 0.24 million tons for the ten-month period. Finally, Kos had emissions of 0.2 million tons, slightly exceeding the emissions of the station on the island of Thira.
According to the revised National Energy and Climate Plan (NECP) submitted in January 2025 to the European Commission, the target for 2030 is a maximum of 4 million tons of emissions from all three fuels (lignite, fossil gas, oil). This marks a substantial decrease (-91%) compared to 2013, the year in which thermal power plants first began paying for their carbon emissions under the Emissions Trading System (ETS).
In the final NECP, the estimated emissions for 2025 are 10.2 million tons. In the first ten months of 2025, a total of 12.9 million tons is estimated to have been emitted from the sector, meaning that the sector has exceeded the available carbon budget for 2025 by 2.7 million tons and the country is over the target set in the NECP, which has already been the case since August.
You can explore how electricity sector emissions evolved since 2013, as well as find analyses from previous months here.
[1] Carbon intensity is defined as the ratio of emissions from the three fuels (lignite, gas and oil, including CHP) to the country’s total electricity production from the interconnected grid and the non-interconnected islands.
