UK's National Grid prepares for tight power supply

Cold weather causing surge in demand, with wind generation also low

The UK network has struggled to balance the grid in times of high demand. PA

National Grid ESO issued a warning over a tight power supply in the UK on Tuesday and has asked coal-fired plants to stand by, as a cold snap has caused a shortage in electricity.

The shortfall is up to 980 megawatts — larger than the current contingency requirement of 700 megawatts, National Grid plc reported. The utility is leaning on coal to boost supplies, asking three more units to prepare to generate after requesting an Electricite de France SA unit to warm up on Monday.

In addition to the cold weather, wind generation has slumped, providing only 13 per cent of the nation's power, according to grid data from Bloomberg.

The UK network has struggled to balance the grid in times of high demand, especially during cold weather when wind generation is low. National Grid is operating the system with a shrinking fleet of conventional generation, as old coal and nuclear plants are shut down.

The electricity market notice was triggered by the grid manager's control room because the shortage could not be addressed through usual measures such as asking power plants to generate more or by cutting consumption.

National Grid emphasised that this notice does not mean power cuts are imminent. The next step in the power market would be a High Risk of Demand Control warning or Demand Control Imminent notification — neither of which have ever been used.

In these situations, local grids might reduce voltage to manage demand or temporarily disconnect some consumers.

National Grid is leaning on coal to potentially boost supplies. EPA

The company is also using a demand flexibility service (DFS) to reward customers for not using appliances during peak demand periods.

The DFS provides discounts on power bills for customers who turn off appliances such as ovens and dishwashers when electricity demand is high. Households with pre-agreed upon contracts may be asked to cut demand on Wednesday to help balance the grid during peak times.

The Met Office has issued weather warnings for snow throughout the UK through Friday. Wintry conditions will continue on Friday in northern areas, with some places receiving as much as 10 centimetres of snow.

National Grid has not secured a contingency reserve of coal units for next year, and two plants are scheduled to close permanently at the end of March.