For the first time, it is operating a scheme called the Demand Flexibility Service, where customers get incentives if they agree to use less power during crunch periods.

The operator said the move did not mean electricity supplies were at risk

And advised people not to worry.

These measures were announced to "ensure that everyone gets the electricity they need".

That's according to the firm's Head of National Control.

Back in December the company said that over a million British households had signed up for the scheme.

National Grid has also asked for three coal-powered generators to be put on standby

As the country faces a cold snap.

This announcement does not mean they will definitely be used, it said in a separate statement.

The coal-powered generators were last put on standby in December - but they were not needed then.

Below freezing temperatures have been recorded across much of the UK in recent days, with national weather service the Met Office last week issuing severe weather warnings for snow and ice.