Since the start of summer, Spain has been experiencing weeks of heat waves with record highs. This is due to the fact that climate change is causing the Earth’s temperature to increase from one year to the next. The extreme temperatures are causing damage not only to people’s health but also to the environment with fires and storms and to photovoltaic systems, as they no longer produce energy when it is hot.


People think that photovoltaic panels generate more energy the hotter it is, but this is completely false.  This is because photovoltaic solar panels produce energy thanks to light and not heat. In fact, high temperatures have a negative effect on the performance of photovoltaic panels – heat does not agree with solar panels!

In order to produce energy, solar panels need solar radiation, which is not the same as ambient temperature. Therefore, it is possible to have good solar radiation without excessive temperatures. In the spring season, for example, solar panels work more efficiently than in summer, as there is good quality solar radiation and the temperature is milder.

The peak power of a solar panel is the maximum electrical power that can be generated. It is only at this point that 100% of the photovoltaic cells’ performance is obtained. We will only see 100% of the production on sunny winter days, i.e. if we install 100 Kwp in solar panels, it is normal that only on sunny winter days will we reach this peak production.

As we have seen, as the temperature rises, the yield decreases. Most manufacturers claim that at 40 degrees, solar panel performance is usually around 80% efficiency. The ideal temperature for maximum production is between 20 and 25 degrees.

Some recommendations that we can follow for a good management of a photovoltaic installation to avoid problems are the following:

– Install inverters and monitors to avoid overheating of the installation.

– Leave space between the panels and the surface, as this will provide more ventilation and will not absorb heat directly.

– Use distribution sheets on the panel, these distribute the temperature to a specific point.

– Use panels with cooling, which can increase efficiency by 20%.

Undoubtedly, the successive heat waves that we are experiencing in our country are wreaking damaging havoc during their passage, even in photovoltaic systems.