It’s getting hotter and hotter. That’s why experts began to worry about solar panels

There is a delicate balance for solar panels. Obviously, these panels require solar energy to operate; However, heat also causes some loss of efficiency. So much so that there are those who think it could compromise his ability to function. They can breathe easy.

Less efficiency, more product.Photovoltaic panels typically reach maximum efficiency when the panel temperature (not the ambient temperature) is around 25°C. Above this temperature, their ability to use energy decreases. According to some calculations, for each additional degree, these devices lose from 0.05 to 0.34% of efficiency.

Loss of efficiency. This can result in a loss of efficiency of 10 to 25% due to high temperatures. What happens is that high temperatures tend to correlate with higher levels of solar radiation, so the fraction of energy they manage to convert is lower and the total amount of energy they receive is usually higher in these kinds of situations.

Explanation. “It’s not a big problem. High temperatures have only a small effect on overall solar energy production (this is a side effect). If (the weather) is sunny and hot, you will get good energy results. “This is not falling off a cliff,” Alastair Buckley from the University of Sheffield explained to Solar Energy UK, an association associated with the sector.

Striving for maximum efficiency. It is impossible to calculate the “golden mean” for these devices for several reasons. First, temperature and solar radiation are correlated but are different variables. Moreover, as we have already mentioned, it is not the ambient temperature, but the temperature at which the panel is located that affects its efficiency. What we do know is that in general an increase in radiation, even if it implies an increase in heat, will have a positive effect on photovoltaic production.

The second thing that makes this calculation difficult is the coexistence of different solar technologies and multiple successive generations of increasingly efficient solar panels. What we do know is that there is no realistic scenario in which solar panels will stop working.

A common problem. The loss of electricity production efficiency on warm days affects, to one degree or another, almost all of our existing generation mechanisms. In the case of photovoltaics, the problem arises because electric current is generated when the sun’s rays excite electrons in the semiconductor wafer. In warm conditions, these electrons are already in high energy states, so more external energy is required to perform this task.

The reason for forms of energy such as thermal and nuclear is that they need to heat water to drive turbines. The higher the ambient temperature, the more energy is required to create this temperature difference. And in these cases the effect is insignificant.

A changing problem. Solar energy is one of the resources we have to combat climate change. But its ability to give us energy may also be limited by its effects.

One might think that countries like Spain could be negatively impacted by the predicted rise in temperature and their ability to generate solar energy. However, a 2015 study predicted that climate change would actually impact photovoltaic production in the Nordic countries more than in the south.

Spain, at an intermediate point. Southern Europe is located in a privileged location for solar energy production. With an average of 2,500 hours of sunshine per year and many provinces exceeding 3,000, solar energy is becoming an increasingly popular option in mixingenergy of the state. There is nothing to suggest that rising temperatures would threaten this fact.

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Image | American Public Power Association

*A previous version of this article was published June 2023.