Power system records

It was a relatively quiet start to the year, with only five of the 168 records we track reaching new highs or lows during the first quarter. The one standout moment was  25 March, when the combined output from Britain’s renewable generators jumped by nearly 4 GW, rising from a previous peak of 31.7 GW to 35.6 GW. The same day also saw low-carbon sources produce more than 40 GW for the first time. Together, Britain’s nuclear, biomass, wind, solar and hydro also had their most productive ever month in February, averaging more than 25 GW.

The tables below look over the past seventeen years and report the record instantaneous output and share of electricity generation, plus sustained averages over a day, a month, and a calendar year. Cells highlighted in blue are records that were broken in the first quarter of 2026. Each number links to the date it occurred on the Electric Insights website, so these records can be explored visually.

(3) Note that Britain has no inter-seasonal electricity storage, so we only report on half-hourly and daily records. Elexon and National Grid only report the output of large pumped hydro storage plants. The operation of battery, flywheel and other storage sites is not publicly available.