Britons have saved almost £3m by using tumble dryers and other power-hungry devices at quieter times, under a scheme that aims to reduce the strain on electricity networks, National Grid has said.

The electricity system operator (ESO) launched an initiative last month to incentivise consumers and businesses to reduce their energy use, by running appliances such as washing machines, dishwashers and tumble dryers before or after particular designated periods when demand was expected to be heavy.

National Grid said on Wednesday the “demand flexibility service” had delivered more than 780 megawatt (MW) hours of demand reduction, and £2.8m in savings over five test periods since the scheme launched last month.

More than 1m households and firms had signed up to participate, it said. Customers are normally given 24 hours notice to shift their power usage from a peak period – typically 4pm to 7pm. Savings are passed on via energy suppliers to customers who have signed up.

Craig Dyke, the head of national control at the ESO, said: “Delivering the first of the demand flexibility service test events is a major milestone in the evolution of consumer flexibility in the UK. This service successfully proves that consumers up and down the country are standing by to get involved in flexibility solutions.”

Separately, gas and power prices fell on Wednesday in signs that the strain on the UK and Europe’s energy supplies was easing despite the icy weather.

A marked increase in nuclear output from power stations in France and hydroelectric power in southern Europe has lifted pressure on electricity supplies across northern Europe.

The UK price for gas for delivery on Thursday fell 4% at 332p a therm, while month-ahead prices were down 5.6% at 322p a therm.

The price of power, which reached a record £675 a megawatt-hour on the Epex Spot SE exchange this week, fell to £353 in a volatile market. Power prices for delivery on Thursday fell nearly 7% in Germany and about 5% in France.

Power prices had soared as the freezing weather forced Britons to increase their heating use, pushing up demand for energy despite high bills.

The cold weather combined with a period of low wind, reducing the production of Britain’s windfarms to close to zero. Emergency power units at Drax in North Yorkshire were put on standby on Monday but ultimately not used.

Live data from ESO on Wednesday showed wind accounting for 27% of electricity generation, behind gas with 47% and ahead of nuclear at 13%.

Separately, French nuclear output has ramped up in recent days and is expected to improve through the week as four more nuclear reactors, which were out of action for maintenance, are due to return.

There have been concerns over power shortages this winter in the UK and Europe amid the fallout from Russia’s invasion of Ukraine. However, the improving weather and resilience of the system so far has brought some encouragement.

Analysts at RBC investment bank said: “Despite this grim scenario for the week, we could see that the electricity system is coping relatively well with the situation, albeit power prices suffered a significant increase.

“Despite the increase in gas demand on cold weather and low wind resource, we could see how gas storage levels are doing better even this week on any single day v the same day last year.”

The rise in prices will have increased the cost of the government’s energy price guarantee scheme, which aims to cushion the blow of rising wholesale costs.

The energy regulator is pushing for a cap on how much power stations can charge National Grid for backup electricity. Ofgem wants to tighten rules to prevent “excessive” profits and intends to publish proposals early next year, the Daily Telegraph reports.

The Grid spent more than £27m paying power stations to crank up supplies at short notice on Monday.