Half of all grid-scale energy generation in 2025 was from renewable sources, figures show

Imports made up 17% of Ireland’s electricity grid supply last year, according to newly released figures by the Central Statistics Office (CSO).

The country’s electricity grid supply increased by 3.5% in 2025, when compared with 2024; the CSO says that the majority of the increase in supply came from net imports.

Net imports of electricity were 6,130 gigawatt hours in 2025; this was an increase of 1,069 gigawatt hours compared with 2024.

There was an increase in energy generation in 2025; this was 29,335 gigawatt-hours, which was a slight increase from 29,267 in 2024.

The CSO say that half of all grid-scale electricity that was generated in 2025 was from renewable sources. Wind was the largest renewable source, which provided 40% of all generated electricity.

Gas was the largest energy source used for generating electricity in 2025; this was responsible for 47% of the entire generation.

Orla McCarthy, Senior Statistician in the Climate and Energy Division of the CSO, said: “Electricity supply in this release refers to output from main activity producers, whose primary activity is the supply of electricity to the grid for sale to other parties. It does not include all supply from autoproducers who generate electricity primarily for their own use, for example generation from rooftop solar panels. The total grid supply referred to in this release is the sum of generated electricity, net imports, and storage output.

“Ireland’s electricity grid supply grew by 3.5% to 35,884 GWh in 2025 compared with a supply of 34,684 GWh in 2024. The increase in supply largely came from increases in net imports of electricity.

“In 2025, net imports of electricity were 6,130 GWh, which made up 17% of grid supply. Net imports of electricity rose by 21% in 2025 compared with 2024, and by 87% when comparing with 2023.

“Generated electricity, which provided 82% of grid supply in 2025, has remained relatively flat over the past couple of years. In 2025, 29,335 GWh of electricity was generated which was very similar to electricity generation of 29,267 GWh in 2024, and a small decrease of 1% compared with 2023. However different trends were seen in generation from renewable /and non-renewable sources.

“Gas, which is non-renewable, was the largest generation source in 2025, responsible for 47% of generated electricity. In 2025, gas generated 13,918 GWh of electricity, which was a 1% decrease compared with 14,036 GWh in 2024.

“Generation from wind, which is the second largest electricity generation source, and the largest renewable source, was 11,782 GWh in 2025 which was a 3% increase over 2024.

“Solar generation rose sharply in the past couple of years. In 2025 1,101 GWh of electricity was generated by grid-scale solar farms, which was 51% more than in 2024. Overall grid-scale solar farms made up 4% of generated electricity in 2025.

“Electricity generation from coal fired power stations showed a significant decrease in 2025, with 453 GWh generated, which was 52% less than in 2024 and in June 2025 Ireland stopped all generation of electricity from coal.

“This release focusses on electricity supply to the grid by main activity producers in 2025, providing detail on the supply source at monthly, daily, and hourly granularity. It demonstrates how factors such as the weather, temperature, time of year, and time of day can impact both the total electricity supply and the energy source.

“Winter months have higher electricity supply than summer months. In 2025, December had the highest monthly average daily electricity supply at 108 GWh, May had the lowest average daily electricity supply to the grid at 90 GWh, 17% lower than December.

“The electricity supply source also shows seasonal variation. In winter a higher share of electricity is generated from wind than in summer, due to typically higher mean wind speeds.

“In 2025, February had the highest monthly share of electricity supply from wind at 49% of total supply, whilst May had the lowest at 22%. However, May had the highest amount of solar electricity generation in 2025 with a daily average of 5.66 GWh.

“In 2025, half of generated electricity came from renewable sources, however on a daily basis there was a large variation in the renewable share. The highest renewable generation share in 2025 was 86% on 23 February, the lowest was 11% on 20 January, largely due to differences in wind generation.

“There is a consistent daily pattern to electricity demand, with a peak in the evening and a low point in the early morning. The peak monthly average supply time was 5pm to 6pm in November 2025, when average supply was 5.26 GWh. The lowest average monthly supply was between 4am and 5am in June 2025, at 3.26 GWh.

“Overall, in 2025 electricity storage output contributed a small share of electricity grid supply, at 1%. However, during the high demand period of 5pm to 6pm electricity storage output, from pumped hydro and battery discharge combined, provided up to 13% of electricity supply.”