Demand flexibility means moving electricity use to a different time, or turning it up or down on request, so that demand fits the supply available. The washing still gets done and the car still gets charged; it just happens when the grid can supply it more easily.
How it works
Flexibility can come from almost any load that does not need to run at an exact moment: electric car charging, heat pumps and hot-water tanks, home batteries, factory processes and commercial cooling. An energy supplier or aggregator groups many of these together and offers the combined change to the grid or responds to price signals on a customer’s behalf.
The Demand Flexibility Service
The National Energy System Operator (NESO) launched its Demand Flexibility Service (DFS) in winter 2022/23 to pay households and businesses for cutting use at the evening peak. In winter 2024/25 about 1.98 million consumers were signed up, and the service was used 44 times, reducing or shifting about 3,918 MWh.
The service has since changed:
| Date | Change |
|---|---|
| 27 November 2024 | Became a year-round tool, used when cheaper than the alternatives |
| 9 April 2026 | Added paid turn-up as well as turn-down, local (zonal) requests and a lower 0.1 MW minimum size |
| 7 October 2026 | Began buying actions to manage network bottlenecks |
Households take part through a registered provider, usually their energy supplier, rather than dealing with NESO directly.
Smart tariffs
The other route is price. Time-of-use tariffs charge less for electricity at off-peak times, and some change every half hour in line with wholesale prices. They need a smart meter that records use by half hour. A household with an electric car or heat pump can shift a large share of its use into cheaper periods without any action on the day.
Why it matters
Shifting demand is usually cheaper than building extra power stations or cables to meet a short peak. It also lets more wind and solar power be used when it is available instead of being curtailed.
Read more: Smart grids and microgrids: how a flexible electricity system works.