Solar energy vs. fossil fuels: A clear winner

As the Daily News reported, in this debate one must always distinguish between global warming and regional microclimate. According to researchers at Fraunhofer ISE, solar energy is many times less harmful to the climate on a global scale than fossil energy sources. Solar systems emit significantly lower amounts of carbon dioxide (CO₂) than, for example, coal-fired power plants. As a result, electricity generation via photovoltaics noticeably slows down the greenhouse effect, according to the research published fact sheetBy comparison, one kilowatt hour of brown coal power produces over 1,000 grams of CO₂ from the fuel alone. Solar power, on the other hand, produces just 20 to 40 grams.

Last but not least, the ecological footprint of a solar system also depends on which power source was used for its production. Sebastian Nold from Fraunhofer ISE explains that although the “energy used to produce PV modules” releases CO₂, the systems do not emit any greenhouse gases during operation.

Andreas Schlumberger from Solar Cluster Baden-Württemberg, however, criticises the fact that Relocation of production facilities for solar modules abroad often has a negative impact on the carbon footprint of the systems. Environmental standards in countries like China are often much less strict than in this country. The long transport routes lead to additional environmental pollution, the industry expert continued. Nevertheless, in direct comparison to energy generation using fossil fuels, solar energy is clearly ahead in terms of climate efficiency.

Temperature increase due to reflection of the modules?

The researchers also investigated the claim that the ambient temperature rises due to the reflection of sunlight on the dark solar modules. As Matthias Mauder from the Karlsruhe Institute of Technology explains, a rise in the temperature of the ambient air caused by solar modules can actually be proven under certain conditions. This is the case in deserts, for example, where the contrast between light sand and dark solar modules is particularly great. The color difference in turn means that the air above the solar system is actually somewhat warmer than if there were no system in that location.

In urban areas, however, this effect is much less pronounced. On the contrary: According to Fraunhofer ISE, many PV modules “tend to lead to a reduction in heat in the city”. In an approved research project, meteorologist Mauder now wants to gain further insights into how solar systems influence the local microclimate.