Heatwave pushes Great Britain’s grid operator to call for extra electricity from power plants

Lead

A prolonged heatwave across Europe has prompted Great Britain's energy system operator to issue a rare summer warning, asking power generators to provide extra electricity to meet soaring demand. The National Energy System Operator (Neso) has flagged potential tight margins on the electricity system for Friday evening, marking the second such notice this week.

Coverage Comparison

The Guardian's reports detail Neso's repeated warnings, which have come as temperatures are expected to climb to 34C in parts of southern England, with the hot weather forecast to last more than 10 days. The operator has emphasized that the electricity supply is not at risk and that a blackout is not imminent, but the notices highlight the strain on the system as households turn on fans and air conditioners.

Neso, which manages the energy system in England, Scotland, and Wales, has asked generators to provide any additional capacity they can. This follows a similar call earlier in the week, when the operator paid well above the usual market price to secure supplies. On Tuesday, Great Britain imported electricity from Europe at more than six times the normal price between 5pm and 7pm, according to The Guardian. The operator paid about £470 per megawatt-hour for imports, compared with an average of £71 per megawatt-hour in June last year.

The heatwave has also disrupted generation across the continent. The Guardian reports that several gas power plants in the UK have cut output due to the heat, and five plants reported they would need to reduce output by a total of about 2.5 gigawatts due to 'ambient' conditions. In France, which supplies a significant proportion of the UK's electricity, the state-owned utility EDF has warned that the heatwave is putting a strain on its nuclear reactors, with some plants reporting unplanned outages because river water temperatures have climbed too high for cooling.

The combination of low wind speeds and reduced nuclear output has led to a sharp rise in electricity prices across European markets. In Germany, power prices were forecast to reach highs of more than €545 per megawatt-hour on Tuesday evening, the highest since June 2024, according to the Epex Spot exchange. In France, prices climbed to over €268 per megawatt-hour, the highest since August 2023.

The UK's ambulance service has also issued advice as the heatwave continues. The South Western ambulance service advised people to check on elderly family members and friends, with its deputy director of clinical care, Adrian South, telling the BBC that older people have less perception of their body temperature and can be particularly affected by heat.

The Met Office said the current spell of hot weather is likely to continue into the next week, with today and tomorrow expected to be the hottest days in this heatwave, with temperatures of up to 36C in some areas. Parts of France are covered by orange extreme heat warnings, with temperatures there expected to reach up to 43C.

Key Claims

• Neso issued an electricity margin notice on Thursday evening, asking generators to provide extra electricity to meet demand on Friday evening. The operator said its forecasts showed 'tight margins on the electricity system' due to 'the impact of extremely high temperatures affecting Great Britain and the continent'.
• This was the second such notice in a week; Neso also called for backup on Tuesday night ahead of a rise in demand on Wednesday evening.
• The electricity supply is not at risk, and the notice does not mean a blackout is imminent, according to Neso.
• Several gas power plants in the UK have cut their output due to the heat, and in France, four nuclear power plants reported unplanned outages because river water temperatures had climbed too high for cooling, as reported by The Guardian.
• Great Britain imported electricity from Europe at more than six times the normal price on Tuesday, paying about £470 per megawatt-hour between 5pm and 7pm.
• The heatwave has prompted a sharp rise in electricity prices across European markets, with prices in Germany and France reaching multi-year highs.
• The South Western ambulance service advised people to check on elderly family members and friends, as older people have less perception of their body temperature.
• The Met Office said the hot weather is likely to continue into the next week, with temperatures expected to start gradually going down from Sunday night.
• Parts of southern England are expected to reach highs of 34C, and the hot weather is expected to last over 10 days.
• The UK Health and Safety Agency has issued amber heat-health alerts covering parts of the country until 9pm on Sunday.

Perspectives

The Guardian reports that Neso has stated that electricity supply is not at risk and the warnings are routine tools to balance the system, urging that there is no risk to customer supplies. In contrast, The Guardian also highlights concerns from the energy industry, with Shivam Malhotra, head of power trading at consultancy LCP Delta, noting that it was 'not unusual' to see unplanned outages at British gas plants, which 'tend to really struggle in extreme temperatures.' Additionally, the South Western ambulance service has expressed concern about the health risks, particularly for the elderly.