Almost 40% of Ireland’s electricity was supplied by renewable sources in January, as the country’s power system recorded new demand highs for both Saturdays and Sundays, according to provisional data from transmission system operator EirGrid.

The figures show that renewables accounted for 39% of total electricity generation during the month, broadly in line with the same period last year, when official data confirmed that renewables supplied 40% of Ireland’s electricity in January 2025.

Wind power remained the backbone of Ireland’s renewable output, providing 33% of total electricity demand. Total wind generation reached 1,119 GWh, down from 1,243 GWh recorded in December.

Although solar energy contributed just under 1% to the overall fuel mix in January, it still played a role during brighter periods, underlining its growing importance even during winter months. Grid-scale solar generation peaked at 371 MW on Wednesday, 28 January at 12:45 pm, accounting for around 8% of system demand at that moment. At the same time, an estimated equivalent amount of embedded solar generation, mainly from rooftop installations, further reduced overall system demand.

Gas-fired generation continued to dominate the energy mix, representing 44% of total electricity supplied during the month, while 16% of demand was met through electricity imports via interconnectors.

Weekend demand reaches new highs

January also saw new all-time highs for electricity demand on both Saturdays and Sundays. On Saturday, 3 January, demand peaked at 5,297 MW at 5:39 pm, marking the highest Saturday demand in twelve months, surpassing the previous record set on 4 January 2025.

Similarly, on Sunday, 4 January, demand reached 5,480 MW at 5:31 pm, exceeding the previous Sunday record recorded on 30 November 2025.

Total electricity demand across the system amounted to 3,409 GWh in January, up from 3,234 GWh in December and 2,894 GWh in January 2025, reflecting sustained consumption levels during the winter period.

Despite these increases, the overall peak system demand in January remained below the 6,000 MW threshold. The monthly maximum of 5,916 MW was recorded on Monday, 5 January at 5:47 pm, compared with the all-time high of 6,024 MW reached in January 2025. EirGrid attributed this difference mainly to milder temperatures this year.

High demand and strong renewable contribution

Commenting on the figures, Diarmaid Gillespie, EirGrid’s Director of System Operations, said that high system demand observed in recent months continued into January, particularly during the first weekend of the year.

“Notably, record demand peaks were recorded on both a Saturday and a Sunday, with the Saturday peak on 3 January being the highest ever recorded for that day since the same weekend last year,” Gillespie said. “Parts of the country experienced a cold snap with snow and ice during that first weekend, which partly explains the elevated electricity demand.”

He also highlighted the ongoing role of renewables in Ireland’s power mix. “Consistent with recent trends, January once again saw a significant contribution from renewable energy to the overall fuel mix,” Gillespie added.