Provisional data released by EirGrid reveals that 39% of Ireland's electricity was generated from renewable sources during the month of May. This represents a notable increase from the 33% recorded for the same month last year.

May proved to be a standout month for solar energy generation, which contributed 7.8% to the overall fuel mix. This figures higher than the 5.7% recorded in April and the 6% documented in May 2025.

Driven by sunnier weather conditions, a sequence of new generation peaks occurred throughout the month. The highest milestone was reached on Monday 25 May, when grid-scale solar power achieved a record output, contributing 1,222 MW to Ireland's electricity network. This follows another major achievement in April, when electricity provided by grid-scale solar crossed the 1 GW (gigawatt) threshold for the first time.

Wind energy also maintained a substantial footprint, accounting for 28% of the total energy generated across the month, with a total output reaching 784 GWh (Gigawatt hours).

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Regarding other generation sources in May, gas generation accounted for 41% of the total electricity consumed, while 21% of the supply was imported via interconnection. The overall national electricity system demand stood at 2,794 GWh for the month, dropping slightly from the 2,865 GWh required in April.

EirGrid's National Control Centre manages the complex task of balancing variable renewable inputs alongside conventional generation sources to reliably meet grid demand. Significant engineering progress has allowed up to 75% of Ireland's electricity to come from variable renewable sources like wind and solar at any single point in time. An active development programme is currently underway to increase this operational limit to 95%.

EirGrid noted that due to the high volume of daytime solar generation during May, there were days where early afternoon electricity demand from the grid dropped to levels similar to overnight demand. This phenomenon is largely attributed to embedded solar generation, such as residential rooftop panels, directly meeting local demand before it reaches the wider transmission grid.

Diarmaid Gillespie, EirGrid's Director of System Operations, stated: "May was another significant month for renewable energy sources powering the electricity system in Ireland. The amount of solar energy was notable once again given the good weather and an increased amount of grid-scale solar on the system.

"With solar power making almost 8% of the overall fuel mix, as well as the peak records set during the month of May, we have seen again just how important it has become as a source of renewable energy."