Provisional EirGrid data shows renewables supplied around 41% of Ireland’s electricity in November.
The operator said wind provided 35% of all electricity used, totalling 1067GWh.
Other renewables including solar and hydropower brought the overall share to 41%.
Gas generation delivered 42% of supply, while 17% was imported via interconnection.
Electricity demand reached 3088GWh for the month, up from 2969GWh in October.
EirGrid reported a new Sunday peak of 5144MW on 30 November.
Battery discharge also set a new transmission-system record at 362MW on 25 November when demand was high and wind output was low.
This follows a market update that now allows Energy Storage Power Stations to be fully integrated into real-time operations for more efficient charging and discharging.
“As we would expect in November, with the clocks having changed, evenings getting shorter and the weather colder, we continued to see an increase in demand on the system last month,” said EirGrid director of system operations Diarmaid Gillespie.
He added: “Notably we saw the highest demand for a Sunday since January of this year with batteries playing an ever increasing role in meeting peak demand on the power system.”