Ireland’s national grid hit a milestone in May 2025 with record-breaking solar-generation figures from utility-scale installations. These large-scale solar farms generated 173,163 MWh of electricity—equivalent to 6.5 per cent of all generation that month—up from just 2.7 per cent (71,731 MWh) in May 2023.
Across the month, solar output saw several brief but significant spikes. On 17 May, the system recorded a one-minute peak of 755 MW, surpassing the earlier records of 752 MW on 15 May and 750 MW on 24 March. This solar milestone followed an earlier wind-power record set in February, underscoring the growing strength of renewables on Ireland’s grid.
Electricity demand stood at 2,671 GWh in May—a negligible change from the 2,679 GWh seen in May 2024. Importantly, the grid is now capable of integrating up to 75 per cent renewable generation at any given moment, a technical ceiling known as the system non‑synchronous penetration (SNSP) limit.
To support further growth in renewables, especially variable sources like wind and solar, EirGrid has launched a major grid reinforcement programme. This includes upgrades to substations, reinforcements of existing lines, and new infrastructure to enhance capacity and network resilience, ensuring that higher shares of renewables can be accommodated safely.
Diarmaid Gillespie, Director of System Operations at EirGrid, explained that while onshore wind remains the dominant renewable resource, solar is becoming increasingly significant—particularly during bright summer days—and may set additional records in the months ahead. Integrating variable renewables alongside traditional generation and imports poses complex technical challenges. Stability of voltage, frequency, and reserve capacity must be managed in real time, and EirGrid’s engineers continually adjust operational protocols to maintain a secure and reliable supply.
Key figures – May 2025
Solar generation: 173,163 MWh (6.5 per cent)
Wind generation: 22.5 per cent
Total renewables: 32.5 per cent
Peak solar output: 755 MW (one-minute peak on 17 May)
Fuel mix: Gas 39 per cent, Imports 22.8 per cent, Coal 4.6 per cent, Other 1.1 per cent
Grid demand: 2,671 GWh
SNSP limit: 75 per cent
These figures demonstrate how rapidly solar generation has scaled up in Ireland’s energy system. With ongoing upgrades to the grid and further innovation in network control, the country is better equipped to handle high proportions of variable renewables. Summer may bring new records and technical milestones.
Source: EirGrid
