Gas was central to Ireland’s energy mix in 2025, underpinning the electricity system, according to Gas Networks Ireland’s annual gas demand statement 2025

• Gas generated 40% of Ireland’s electricity in 2025
• Overall gas demand fell by 1.5% year-on-year in 2025

Gas played a key role in generating electricity in Ireland last year, as it accounted for two-fifths of electricity and was a key back-up for renewable electricity sources, according to Gas Networks Ireland.

Overall gas demand in Ireland fell slightly in 2025, declining by 1.5 per cent compared with 2024, according to Gas Networks Ireland’s annual gas demand statement. The reduction was reflected across most sectors of the economy, while gas continued to play a central role in supporting electricity generation and meeting seasonal demand throughout the year.

Transport was an outlier last year as gas demand rose by 10 per cent in 2025 compared with 2024. This increase reflects the continued shift towards the use of compressed natural gas (CNG) and renewable BioCNG in heavy transport fleets.

Electricity generation

Gas continued to play a central role in supporting the electricity system, generating 40 per cent of the country’s electricity in 2025, slightly down from 41 per cent in 2024. The contribution of gas to electricity generation peaked at 92 per cent in July and did not fall below 11 per cent at any point during the year², underlining the importance of gas in maintaining energy stability when weather dependent renewable energy is unavailable.

Wind energy generated 33 per cent of Ireland’s electricity in 2025, which was unchanged from 2024, and peaked at 78 per cent at times during the year2. Solar generation increased its contribution to three per cent, up from two per cent in 2024. 

Commenting on the annual figures, Gas Networks Ireland’s Director of Strategy and Regulation, Edwina Nyhan, said:

“The 2025 gas demand figures highlight the continued importance of gas in Ireland’s energy system. While overall demand was slightly lower year-on-year, gas remained a critical source of flexibility and security throughout the year, supporting electricity generation during periods of variable renewable output and meeting seasonal heating demand across homes and businesses. As Ireland’s energy system continues to evolve, gas will remain essential to maintaining system stability and resilience.”

Monthly gas demand patterns in 2025

Monthly gas demand patterns throughout 2025 reflected changing weather conditions and variations in electricity generation requirements. 

At the start of the year, in a cool and sunny month with record breaking wind gusts due to Storm Éowyn, overall gas demand increased by 17 per cent in January 2025, compared to December 2024. The highest ever gas demand day for the Republic of Ireland was recorded on January 8th, with January 9th ranking as the third highest. These peaks were driven by a combination of high gas demand for electricity generation and low temperatures. 

February saw a sharp fall in gas demand as milder temperatures and strong wind generation reduced gas use. Gas demand rose again in March due to weather shifts and a fall in wind energy output, increasing by 13 per cent month-on-month.

Overall gas demand declined through the spring and early summer months. Demand fell by 12 per cent month-on-month in April and by a further 11 per cent in May. In June, gas demand decreased by nine per cent compared with May.

During July, gas generated over half of Ireland’s electricity, peaking at 92 per cent and never falling below 17 per cent, ensuring stability during periods of low wind output² .

In August, overall gas demand was nine per cent higher than in August 2024, despite the month being the fourth warmest August on record. Increased gas use for electricity generation contributed to this rise as coal was phased out of the generation mix. 

September saw residential gas demand almost triple as cooler and wetter conditions prompted households to turn on their heating earlier in the season. In October, overall gas demand increased by 19 per cent compared with September as cooler, wetter weather and the arrival of the first named storm of the winter season Storm Amy, led to higher energy use across homes, offices and commercial sectors. 

November saw a further increase in gas demand of 15 per cent compared with October. The year ended with gas demand remaining the same in December versus the previous month.

^{1 Annual Climate Statement for 2025 - Met Éireann - The Irish Meteorological Service}

^{2  All peak and low measurements recorded over a 15-minute resolution}