The operator of Britain's unified energy system, National Grid, is asking some households to cut energy consumption as declining wind power and sub-zero temperatures across the country test its ability to provide customers with electricity, Bloomberg writes.

National Grid Plc is using an emergency tool for the first time to ease supply shortages. Starting at 5 p.m., customers of Centrica Plc, EON SE and Octopus Energy Ltd. who signed up for the program will be asked not to use dishwashers or washing machines for two hours during peak demand.

The measure is a stark reminder that Europe's electricity crisis is far from over, and highlights the dangers of Britain's steadily shrinking generation buffer. It also makes the country more dependent on imports from France, which is struggling with its own nuclear crisis and cannot export as much as before.

The fact that we are being asked to respond to demand shows that we need to remain vigilant and cautious about what may happen in the future, said Jonathan Brearley, executive director of the Ofgem regulator.

The dramatically colder weather in recent days has caused a surge in demand, with prices during peak hours reaching their highest level since Dec. 21.

The grid operator had previously instructed three standby coal-fired power plants to prepare to operate Monday night, but later rescinded the instruction.