It was the dunkelflaute
Low levels of renewable generation and high demand drove gas-fired power generation to its highest level since 2021 for the first quarter of the year.
That was the standout highlight in a new report on the British power generation market by Montel Analytics.
Montel’s study showed that electricity generated by combined cycle gas turbines (CCGTs) increased to 26.8TWh over the first three months of 2025 – a rise of 13% from Q4 2024 and the highest Q1 level of CCGT generation for four years.
This surge was driven by a fall in renewable generation owing to intervals of high winter demand and periods of ‘dunkelflaute’, in which demand is high while there is little to no wind or solar generation.
Domestic demand for the quarter was 66.3TWh, a 6% increase from Q4 2024 and the highest Q1 demand since 2022. Meanwhile, renewable output fell from 35.8TWh in Q1 2024 to 34.1TWh in the first quarter of this year, mainly due to a decline in wind and biomass output. Wind generation during the quarter totalled only 22.3TWh – the lowest first quarter output since 2020.
In the first half of Q1, gas prices continued the upward trend observed in the previous two quarters, climbing to a peak of £49.30/MWh on February 10, the highest daily value since March 2023. They then generally declined throughout the latter half of the quarter as the weather became milder.
During high demand periods and low renewable conditions in a cold spell on January 8, the National Energy System Operator (NESO) issued an Electricity Market Notice and a Capacity Market Notice, which was later cancelled as gas generation became available. The system price reached a peak of £2,900/MWh on that day, the highest observed since January 2022, while the wholesale price hit £300/MWh during peak periods on that day.
Despite the fall in output, renewable power sources collectively were the dominant contributor to Britain’s fuel mix in the first quarter, accounting for 44% of the total.
Gas-fired generation made up 35%, a significant rise from the 29% recorded in Q1 2024. Nuclear (12%) and imports (10%) accounted for the rest.
