Irish Grid Monthly: October 2026

Hello! We just had an interesting month for data and the Irish grid, with SEMO (the market operator and our source of unit-level data) experiencing what must have been a catastrophic IT outage towards the end of the month: all publication was suspended for about two days, and not all data has yet been backfilled. If anybody can shine some light on what happened, we would love to hear from you. We've done our best to work around the remaining gaps – please enjoy, because October 2026 was another great month for renewables on the Irish grid.

TL;DR

• Ireland’s electricity demand met by source, October 2026
  • 46.4% renewables (40.5% wind, 3.4% solar, 1.5% biomass, 0.9% hydro)
  • 39.8% fossil fuels (38.4% gas, 1.4% waste-to-energy, <0.1% oil)
  • 1.5% storage (0.8% pumped storage, 0.7% batteries)
  • 12.2% net imports

• Second windiest October with 18% of dispatch down: Wind was the single largest source of electricity during October. This has only occurred in an October month once before in October 2022 and has now been the case in four separate months of 2026: something unprecedented on the Irish grid.
• New battery discharge record of 486MW on October 8 plus notable battery events on October 25: There was a large spread in wholesale prices on October 25, going from zero during most of the day to 459 euro/MWh later in the evening. This led batteries to discharge for a longer period than typical evening peak hours.
• Lowest generation from fossil fuels in an October month, hence the lowest volume of CO2 and lowest average grid carbon intensity yet during an October month: It's worth noting net imports (12.2% of demand) were relatively low compared to the norm since Greenlink was connected, so the low fossil fuels were not only due to imports but also an increase in renewable generation.

Emissions

In October 2026 the Irish grid emitted approximately 630,000 tonnes of CO₂ for an average grid carbon intensity of 192gCO₂/KWh, with highs and lows of 386gCO₂/KWh and 87gCO₂/KWh.

That's both the lowest volume of CO₂ and lowest average grid carbon intensity yet seen during an October month, comfortably beating October 2025's 650,000t and 214gCO₂/KWh. So far in 2026, an impressive eight out of ten months have set new records for carbon emissions.

County-level analysis

The top five renewable-producing counties in October 2026:

1. Kerry
2. Offaly
3. Cork
4. Galway
5. Derry

Winds were particularly strong in the south-west this month, allowing Kerry (boosted somewhat by the return of Drombeg Solar Farm) overtake Offaly despite the Edenderry biomass there plant returning to continuous operation. While available wind was actually lower than last month in the north, Derry nevertheless returns to the top 5 thanks to significantly reduced transmission constraints there.

Deep dive (wind, solar, storage, fossil fuels, etc)