In the first 9 months of 2025, emissions from the power sector reached 11.65 million tons, exceeding the annual carbon budget of the NECP by 1.5 million tons. Fossil gas plants were responsible for 55%, with a record high of 6.45 million tons. Without the 9-month RES curtailments (1,785 GWh), emissions from the sector would have been 10.7 million tons (-8.1%). For September, however, emissions were limited to 1.17 million tons due to reduced total electricity production.
Monthly emissions from each power plant in Greece are estimated based on the latest available electricity production data (September 2025 for the interconnected network and August 2025 for the non-interconnected islands) and the annual CO2 emissions from ETS (2024), following the methodology and assumptions presented here.
In September 2025, the carbon intensity[1] of electricity production increased by 8.6% compared to August, reaching 225.7 g CO2/kWh, mainly due to lower electricity production (-13.6% compared to August) which exceeded the reduction in total emissions this month (-6.1% compared to August).
However, for the first nine months of 2025, the average carbon intensity stood at 251.8 g CO2/kWh, down 7.1% compared to the average carbon intensity in 2024 and continuing the downward trend that began in 2017.
The impact of RES curtailments on carbon intensity is notable. Based on IPTO’s ISP2 and ISP3 forecasts, for the period January to September 2025, RES curtailments totaled 1,785 GWh or 7.9% of total RES production. If this energy were used to reduce the use of fossil fuels, carbon intensity would be 231.4 g CO2/kWh, 8.1% lower than the actual intensity.
Despite the fact that carbon intensity was lower in the first nine months of 2025 than in the previous year, total emissions for the same period reached 11.65 million tons, exceeding those of 2024 for the same period (11.56 million tons) and reaching levels comparable to the first nine months of 2023 (11.76 million tons). This is mainly due to the huge increase in gas use, as there was record electricity production from fossil gas in the first nine months of 2025, reaching 17,183 GWh.
Avoiding high RES curtailments during this period (1,785 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 10.7 million tons, or 0.94 million tons less than actual emissions.
In terms of breakdown of emissions by fuel, emissions from gas-fired power plants for the first nine months of 2025 amounted to 6.45 million tons, 55.3% of total emissions, reaching their highest level since 2013. On the other hand, emissions from lignite-fired plants for the same period set a new all-time low of 2.6 million tons, a 14% decrease compared to the same period in 2024. Emissions from oil-fired plants on non-interconnected islands were 2.3 million tons, down 2.1% compared to last year.
In September alone, the sector’s CO2 emissions were 1.17 million tons, down 6.1% compared to August, and the lowest in the last quarter, despite the relative increase in lignite emissions to 0.16 million tons. Emissions from gas-fired power plants were 0.66 million tons, down 11.7% compared to August, while emissions from oil-fired power plants on non-interconnected islands were 0.32 million tons, down 14.6% compared to August.
In the first nine months of 2025, the lignite-fired power plant of Agios Dimitrios remained at the top of the list of polluters with 1.91 million tons. Despite producing just 1.2 GWh and meeting less than 3% demand, Agios Dimitrios was responsible for 73.5% 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 0.93 million tons for the nine-month period, while Megalopolis V was in third place with 0.77 million tons.
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, displacing the Chania station from the top five. Specifically in Crete, Atherinolakkos recorded emissions of 0.53 million tons and Linoperamata 0.34 million tons for the nine-month period of 2025. On the island of Rhodes, the Rhodes plant recorded emissions of 0.25 million tons, while the N.Rhodes plant noted emissions of 0.22 million tons for the nine-month period. Finally, Kos had emissions of 0.18 million tons, slightly exceeding the emissions of the stations in Chania and Thira.
According to the revised National Energy and Climate Plan (NECP) submitted in January 2025 to the European Commission, emissions in the electricity sector are expected to decrease significantly in the coming years. In particular, 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 nine months of 2025, a total of 10.65 million tons is estimated to have been emitted from the sector, meaning that the sector has exceeded the available carbon budget for 2025 by 1.5 million tons and the country is over the target set in the NECP, which has already been the case since last month.
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.
