As part of the State of Climate in Greece for 2025, conducted by scientists from the Institute for Environmental Research and Sustainable Development at the National Observatory of Athens and organized by the Climatebook information hub, Nikos Mantzaris presented the results of the Green Tank analysis for the electricity generation sector.
The 2025 report provides key scientific data on the progression of the climate crisis in Greece, analyzing trends in meteorological parameters such as temperature, rainfall, soil moisture, snowfall, and wind, as well as their impacts on the environment and society. Key findings include:
- 2025 was the second warmest year in the past 30 years in Greece, with an average annual temperature of 3°C.
- The average maximum temperatures across all regions exceeded the mean value for the period 1991–2020.
- 72% of the days in the year recorded temperatures above the long-term climatic average.
- Inland areas, such as Western Macedonia, Kastoria, Florina, and Grevena, experienced the fastest temperature increases.
The most significant development in the electricity sector in 2025 was the increased use of fossil gas, which affected both the sector’s carbon footprint and wholesale electricity prices. Specifically:
Changes Compared to 2024
Electricity generation from Renewable Energy Sources (RES) increased by 3.8% in 2025 compared to 2024. However, the increase in fossil gas use was more than double (+9.2%), with most of it directed toward exports to meet demand from neighboring countries. Out of the 2.7 TWh change in the interconnection balance between 2024 and 2025, 2 TWh came from increased electricity generation from fossil gas.
Impacts on the Carbon Footprint
Although both lignite—which fell to a new historic low of 2.7 TWh (4.5% of electricity generation)—and oil decreased, the carbon footprint of the electricity sector remained at the same level as the previous year, emitting 15.8 million tons of CO₂. This resulted from increased emissions from fossil gas units, which accounted for 8.8 million tons (56% of the total). Consequently, electricity sector emissions in 2025 were 55% higher than the projections of Greece’s National Energy and Climate Plan (NECP), to which the country had formally committed just one year earlier. According to the NECP, electricity sector emissions should not have exceeded 10.2 million tons of CO₂ in 2025.
Correlation with Electricity Prices
Beyond the negative impact on the carbon footprint, increased fossil gas use also pushed wholesale electricity prices upward. Annual prices rose by 2.7% (from 100.9 €/MWh in 2024 to 103.6 €/MWh in 2025), with the largest differences recorded in January and February, when gas consumption spiked (+58.2% and +100.8% compared to the same months in 2024). Thus, the growth in fossil gas usage to meet both domestic and neighboring countries’ demand offset the benefits of cheaper RES on electricity prices.
RES Curtailment and the Role of Gas
The downward pressure of RES on prices could have been even greater if curtailment had been limited. Curtailment mainly occurs during midday hours, when demand is low, and RES generation is high. Due to insufficient storage infrastructure, excess RES generation cannot be absorbed by the grid and delivered during evening peak hours. As a result, additional RES generation is lost, and prices remain high because extra, expensive gas is still required to meet evening demand peaks.
According to the Daily Unified Scheduling Procedure published by ADMIE, 1,867 GWh of RES were curtailed in 2025, equivalent to 6.6% of total RES generation—more than double the curtailments in 2024 (899 GWh). The highest curtailments occurred in April–May 2025 (359 and 383 GWh, respectively), coinciding with the lowest and third-lowest monthly demand of the year.
You can read the full report [in Greek] here.
