Britain's National Grid Electricity System Operator (ESO) has issued a fresh warning over electricity supplies as a prolonged heatwave continues to drive up demand for cooling across the country. The operator urged households and businesses to limit non-essential power use between 4pm and 7pm on Thursday to help balance the grid.
Second Warning in a Week
This is the second such alert in a week, following a similar call on Monday when temperatures in London reached 38°C. The ESO said it expects peak demand to approach 40 gigawatts, well above the seasonal average of around 35 GW. The warning comes as several gas-fired power plants remain offline for maintenance, and wind generation is forecast to be low.
Grid Under Strain
According to the ESO, the combination of high temperatures, low wind, and reduced generation capacity has left the system with a narrow margin. The operator has access to backup coal-fired units and has asked for additional capacity from interconnectors with France and Belgium. However, it warned that if demand does not ease, it may need to take emergency measures, including temporarily cutting power to some industrial users.
Public Response Urged
“We are asking people to be mindful of their energy use, especially during the late afternoon and early evening when demand peaks,” said Fintan Slye, director of the ESO. “Simple actions like turning off non-essential lights and appliances can make a significant difference.” The Met Office has extended its amber heat warning until Sunday, with temperatures expected to remain in the mid-30s in many areas.
Impact on Renewables and Fossil Fuels
The situation highlights the challenges of integrating renewable energy into the grid. While solar generation has been strong during the day, it drops off in the evening, coinciding with peak demand. The ESO has relied on gas and coal plants to fill the gap, but several units have been offline due to planned maintenance and technical issues. The operator has also activated its Demand Flexibility Service, which rewards households for reducing consumption at peak times.
Government and Industry Reaction
The government has said it is monitoring the situation closely. A spokesperson for the Department for Energy Security and Net Zero stated: “We have a robust energy system, and the ESO has the tools to manage this period of high demand. We encourage everyone to follow the operator's guidance.” Energy analysts have noted that the repeated warnings underscore the need for more storage capacity and demand-side management to cope with extreme weather events.
