Temperature spikes are good for solar panels, right? Answer: it’s hard

This image taken in May 2022 shows solar arrays in Worcestershire, England. The recent hot weather in the UK has sparked a discussion about the optimal conditions for solar energy.

Mike Kemp | In pictures | Getty Images

I saw last week the temperature in the UK jumped, with highs over 40 degrees Celsius (104 degrees Fahrenheit) recorded for the first time.

The news from the UK, which has experienced a series of severe weather-related disruptions, came as other parts of Europe struggled with a heat wave that caused fires, travel delays and death.

On July 20, Solar Energy UK, citing data from the Sheffield Solar PV Live website, said that the country’s solar production “has met up to a quarter of the UK’s electricity demand.” The trade association added that in 24 hours, solar power “provided approximately 66.9 gigawatt hours, or 8.6% of the UK’s electricity needs.”

Many people think that the scorching heat of the last few days will be the best place for solar photovoltaic systems. which directly converts sunlight into electricity.

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Reality is a little more complicated. According to Solar Energy UK, solar power in the UK reaches its optimum power level around 25°C.

“Every degree on either side of that drops by about 0.5%, although the new modules have improved performance,” the post reads.

In a statement, Alastair Buckley, a professor of organic electronics at the University of Sheffield and chief executive of Sheffield Solar, said “that’s why we never see peak production in mid-summer – national production always peaks in April and May when it’s cool and sunny. .” Sheffield Solar is part of the Grantham University Center for a Sustainable Future.

Buckley’s argument is supported by the current UK solar generation record. According to Sheffield Solar, it is 9.89 GW and was reached on April 22, 2021.

Last week’s temperature was well above 25 degrees, but the overall effect didn’t seem to be too damaging. According to Solar Energy UK, a significant increase in capacity will be required for serious problems to occur.

It states that the temperature of the panels is determined by a number of factors: the so-called “solar radiation”, the ambient temperature and the cooling effect of the wind. “A 20% loss in efficiency, which is considered a significant amount, would require them to reach a whopping 65°C.”

So there’s clearly some breathing room for solar panels, but the prospect of higher summer temperatures occurring on a more regular basis doesn’t seem to bother Chris Hewett, chief executive of Solar Energy UK.

“It’s a little better for efficiency in the spring, but essentially, if you have more light, you produce more solar energy,” he said last week.

“You have to remember that solar panels work all over the world. The same technology we use on our rooftops is used in solar farms in the desert of Saudi Arabia.”

Solar power is not the only one affected by rising temperatures in Europe.

Last week it was reported that a nuclear power plant in Switzerland decrease in its performance so that the river that cools it does not reach a temperature level that is dangerous for marine life.

On July 18, the international division of the Swiss Broadcasting Corporation, citing the country’s public broadcaster SRF, said that the Beznau nuclear power plant “temporarily reduced work” to prevent the temperature of the Aare River from rising “to dangerous levels for fish.” “

More broadly, a number of renewable energy companies have highlighted how weather conditions can affect their production. For example, lower wind speeds can interfere with operation.