Solar power reached its highest recorded figure on the national electricity grid in May, while overall almost a third of electricity came from renewable sources last month, according to provisional data from EirGrid.

EirGrid is responsible for operating, developing and enhancing Ireland’s electricity grid and market. It balances electricity supply to customer demand in real time from the National Control Centre.

173,163MWh of electricity was produced from grid-scale solar in May, representing 6.5% of electricity generated for the month. 

For context, in May 2023, 2.7% of all electricity came from solar power, accounting for 71,731MWh of electricity. 

Beating earlier May record

There were also a number of new peaks for grid-scale solar activity for a one-minute period, reaching 755 MW at one point on May 17, 2025, beating the record of 752MW set two days earlier on May 15. 

The previous record of 750MW was recorded on March 24, 2025. This followed a new peak wind power record on the grid set in February.

Of the 32.5% of electricity generated from renewables in May, the majority came from wind, which accounted for 22.5%, while 6.5% came from solar, and the remainder of renewable generation came from other sources including hydro and biomass.

Looking at the rest of the fuel mix, gas generation accounted for 39% of the electricity produced, with 22.8% being imported via interconnection, 4.6% coming from coal, and the remaining 1.1% from other sources.

Overall electricity system demand was 2,671GWh for May 2025, similar to 2,679GWh in May 2024.

Currently the electricity grid can accommodate up to 75% of electricity from renewable sources at any one time: what is known as the system non-synchronous penetration (SNSP) limit.

Upgrades and new infrastructure

EirGrid is rolling out an unprecedented programme of grid reinforcements, upgrades and new infrastructure across the country, enabling the connection of further generation sources to maintain a secure and reliable power supply.

Diarmaid Gillespie, director of system operations at EirGrid, said: “While onshore wind remains the prominent renewable source of electricity in Ireland, solar power has become a notable feature of the Irish power system over the last two years in particular, and we may see further records being reached over the coming summer months. We also continue to see electricity imports contributing significantly to our fuel mix in meeting electricity demand.

"Operating a power system with electricity generated from variable renewables such as wind and solar, mixed with conventional generation, is complex and technically very challenging. To maintain stability on the grid, EirGrid engineers need to be able to adjust to and meet fluctuating energy demand with supply at all times.”