The UK's electricity system operator has issued a plea for more power during this evening's solar eclipse. The National Energy System Operator (Neso) said there would be a shortage of spare capacity between 6pm and 10pm.
It comes as the UK experiences its fullest solar eclipse for the next 54 years, as millions of people across Europe are expected to gather to watch the Sun, the Moon and the Earth line up.
More than 90% of the Sun will be obscured by the Moon between 6.17pm and 8.06pm, the most it has been blocked above UK skies since the total eclipse in 1999.
Growing reliance on solar power
However, since then, the UK - and the rest of Europe - has become ever more reliant on solar power to produce electricity.
NESO issued an “electricity margin notice” for between 6pm and 8pm on Wednesday, when there is an expected shortfall of 1,200 megawatts compared with the amount it would like to be available. The move is an alert to other energy generators to activate any additional capacity they have.
On Tuesday evening, NESO had warned the shortfall could last from 5pm to 8pm, saying the buffer against an electricity shortage could end 1,760 megawatts below the desired amount.
Precautionary measure
A NESO spokesperson said: “We have used our routine tool of issuing an Electricity Margin Notice (EMN) for tomorrow evening’s peak, which simply means we are asking market participants to make any additional generation capacity they may have available.
“The notice has been issued as a precautionary measure to the market due to the solar eclipse and there is no risk to customer electricity supplies.”
Octopus Energy, Britain’s biggest electricity provider, is urging its customer to use less power during the solar eclipse. As a reward for doing this, the supplier said it will give customers who are signed up to its “savings sessions” scheme a free hour of electricity to use next weekend.
Impact on grid and demand
During the celestial event, the amount of solar power generation will temporarily drop - and this will happen at the peak time in the evening when households are home and using energy-heavy appliances.
The notice issued on Tuesday night is the fourth EMN the grid operator has put out this year.
Jess Ralston, head of energy at think tank the Energy and Climate Intelligence Unit, said: “The National Energy System Operator’s electricity margin notice is a standard tool it frequently uses to ask for more power to be available because of tighter margins – it’s a precaution that gives them some extra buffer.
“Today’s eclipse will mean solar power goes offline earlier than usual and coincides with peak electricity demand so having more power sources available on standby is part of running a robust grid, with the UK’s being one of the most reliable in the world while increasingly going green.
“This year has seen more margin notices issued in the summer because of the frequent heatwaves, which are being made worse and more common by climate change, as extreme heat drives up demand from air con and fans while reducing efficiency of many power sources including gas and nuclear. The only way to bring our climate back into balance is to reach net zero emissions, including rolling out more renewables and upgrading the grid after decades of under investment.”
