There short answer is no. Some have blamed renewable energy for the UK’s decision to use coal power for the first time in over a month – but that’s not the case, say green activists, as the mercury rose above 30C.

The National Grid activated Ratcliffe-on-Soar power station in Nottinghamshire yesterday, as more people turned on their air conditioners to cope with the heatwave.

This ended a 46-day streak without coal-generated electricity, the longest since last summer, and drew criticism from environmentalists.

“This is a sign of failure that the National Grid is resorting to one of the most polluting forms of power generation to deal with a summer heatwave that we know has been worsened by climate change”

Ami McCarthy, Greenpeace UK’s political campaigner

However, some commentators also blamed renewable technology. “The heatwave made Solar Panels too hot to work efficiently,” claimed right-wing UK newspaper the Telegraph.

Industry groups stated that’s not the full story, however. More solar power is produced in the summer than any other time – regardless of how hot it gets, as solar energy is produced from sunlight and not heat.

“The idea that solar panels wilt in the heat is a gross and fundamental misapprehension”

Solar Energy UK

Can solar panels cope in the hot weather?

Solar panels are slightly less efficient at higher temperatures. Solar Photovoltaic (PV) cells convert a slightly lower proportion of sunlight into electricity in hotter conditions, solar groups explain.

However, they are built to normally function from about -40C to +85C. Performance does fall when temperatures go above 25C, but only by 0.34 per cent for every additional degree.

According to NXTGEN Energy Ltd, even at close to boiling point, power output would only be around 20 per cent lower.

The UK’s leading technical expert on the technology, Alastair Buckley, Professor of Organic Electronics at the University of Sheffield says that high temperatures only marginally affect the overall output of solar power – it’s a secondary effect. The university provides live Solar PV generation data which backs this up; solar power has been serving around 27 per cent of the UK’s power needs each lunchtime for this past week. Solar panels work perfectly well in the Saudi Arabian desert – and the same panels are being installed there as on rooftops in Birmingham or a field in Oxfordshire.

Coal and gas stations are less efficient in heatwaves too

Solar Energy UK says that heat affects not only solar panels, but also thermal power plants – such as coal, gas and nuclear – that need cool water to operate. As the climate gets warmer, this problem will get worse.

“Solar panels may lose some efficiency in high temperatures, but they are still cheaper and greener than fossil fuels. We need more solar power to fight climate change,” states SolarPower Europe.

“We need to make the most of every ray of sunshine, and we need to prepare the system for the electrified economy. That means investing in the grid and storage, so we can use and distribute renewable energy efficiently”

A new report from the European industry group says that the UK’s solar potential is limited not by the sun, but by the lack of investment in the power network.

“In summer, solar power should be our main source of energy, but we are wasting renewable energy because our grid can’t handle it, and we have hundreds of renewable projects that are stuck because they can’t connect,” said McCarthy.

Coal is already on its way out in the UK. It only produces 2 per cent of the electricity, and it will be phased out by October 2024.

Frequently Asked Questions about Solar Panels

What is the normal operating temperature of a solar panel?

Solar Panels are built to normally function from about -40C to +85C. Performance does fall when temperatures go above 25C, but only by 0.34 per cent for every additional degree.

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