Worries over Britain’s power supply on Monday and Tuesday evenings have been allayed as National Grid decided not to trigger an emergency plan to pay households to reduce electricity use and withdrew a warning of tight margins.

The National Grid Electricity System Operator issued and then rapidly cancelled a notice that warned of tight margins between the amount of electricity available and the amount which will be needed on Monday evening.

It also decided not to trigger the first live run of its Demand Flexibility Service, which pays households to reduce their electricity use and lower the strain on the grid.

The service has been tested twice in recent weeks, and some households earned more than £4 for taking part over the course of an hour.

The first signs that the grid was concerned came on Monday morning at about 10am as it issued an “indication” that it might trigger the DFS for the first time on Tuesday to help lower the risk of blackouts.

It came as experts warned that the difference between supply and demand would be tighter than usual both on Monday and Tuesday evenings, not least as problems with France’s nuclear fleet meant that it would be harder to import electricity from the continent.

Then at 1.33pm the grid issued a separate warning saying that things would be tight on Monday evening at 6pm. These so-called Capacity Market Notices are automated and let electricity generators know that things are tight.

They do not mean that blackouts are likely, just that the margins between supply and demand are smaller than the grid is comfortable with. If blackouts are considered likely then a different type of notice will be issued.

In the last six years there have been 12 such Capacity Market Notices, all of which have been cancelled without incident.

Sure enough, Monday’s notice was withdrawn by National Grid at 2.04pm, just half an hour after being issued.

It is unclear what changed in that time – National Grid did not immediately say – but the likelihood is that its system operators managed to find someone to supply extra electricity into the grid.

The notices have become more common this year as Europe goes through an energy crisis because Russia shut off most of the gas that it supplies to the continent. The most recent notice was sent out last week.

At shortly before 3pm on Monday, National Grid said that it no longer thought it would be necessary to ask households to reduce their power use on Tuesday evening.

“There is no longer considered to be a requirement for DFS,” it said.

Earlier in the day data provider EnergyAppSys had said: “Even though wind is coming back for tomorrow evening’s peak, slow return of nukes in France plus lower temperatures may mean that there is a reduction in available imports across the interconnectors.”

Millions of people around the country will be settling in to watch England play Wales at 7pm on Tuesday in the teams’ final game in the group stages of the World Cup.

The forecasters also warned that margins will be tight in both Britain and France on Monday evening, meaning both countries will need to import power from abroad.

France has been facing months of problems with its nuclear power plants, which generate around three quarters of the country’s electricity.

More than half of the nuclear reactors run by state energy company EDF have closed due to maintenance problems and technical issues.

It has added to a massive energy crisis in Europe as the country faces a winter without its old gas supplier Russia.

Octopus Energy has been the most active energy supplier in the Demand Flexibility Service (Alamy/PA)

So far Octopus Energy has been by far the most active energy supplier in the Demand Flexibility Service.

It released data showing that its customers had helped reduce demand by more than 100 megawatts during both tests. That is the same amount of electricity that a small power plant produces.

Octopus said that some of its customers had earned more than £4 during the hour-long sessions, the average saving was “well over £1”.

The scheme is administered by energy suppliers. Households have to register their interest in taking part in advance. They will then get a text or other message saying that the programme will run later in the day.

If they use less electricity than they normally do during the allotted hours, they will be paid for the savings. The customers will not be punished if they decide to keep using electricity as normal.

So far not many suppliers are taking part but National Grid hopes that participation will increase in the weeks ahead.