The UK's power grid operator has issued a second alert in a week for power stations to increase output, as a heatwave creates a perfect storm of rising demand and reduced wind generation. Gas power stations are set to be paid millions to prevent an energy crunch.
The National Energy System Operator (NESO) issued an electricity margin notice (EMN) late Thursday for Friday evening between 7pm and 10pm, following a similar request on Wednesday that reportedly delivered a £10 million windfall for power station owners.
Heatwave Drives Demand and Cuts Wind Output
The heatwave has led to increased use of air conditioning and electric fans in homes and businesses, boosting electricity demand. Meanwhile, the calm, hot conditions have reduced wind farm output significantly. As of early Friday, gas supplied about 27% of Britain's energy needs, solar contributed 26%, and wind only 18%.
High temperatures across continental Europe have also limited the UK's ability to import electricity, as European countries face their own demand surges. In France, which experienced its hottest day ever, two nuclear power stations were temporarily shut to comply with temperature limits.
NESO Issues Second Alert
NESO's EMN pointed to a potential 446-megawatt shortfall between expected demand and available supply. A NESO spokesperson said: “Our forecasts are showing tight margins on the electricity system for tomorrow evening (Friday). This is due to the impact of extremely high temperatures affecting Great Britain and the continent.”
The alert is a routine tool to signal to the market that a greater safety cushion is needed. NESO stated: “It does not signal that blackouts are imminent or that there is not enough generation to meet current demand.” An insider noted the issue was less about rocketing demand than concerns about where power would come from during the peak evening period.
Imports and Gas Plants Fill the Gap
Data from NESO showed the UK still relied on imports for about 13% of its energy needs on Friday, but supplies from continental power stations have been impacted by their own high demand. Gas power stations are expected to ramp up output to cover the shortfall, earning significant payments under the grid's balancing mechanism.
The heatwave has gripped western Europe, leading to unprecedented temperature highs and putting pressure on energy systems across the region.
