System operator National Grid can use a number of ways to control the supply of electricity if there is a spike in demand:
- It can lower the voltage, which means households may notice lights dimming or flickering
- Industrial customers can also be asked to come off the supply to protect households
More top news
Ahead of its roll-out in Manchester, some Universal Credit recipients describe feeling "trapped" as they wait weeks to receive benefits.
The trial of a soldier accused of trying to kill his wife with a sabotaged parachute has been shown video of how it could be done.
An ITV News investigation has uncovered the staggering scale of disruption caused by over-running roadworks across the country.