Producing them emits hundreds of times less than coal and gas

All energy sources have their dark side and solar is no exception. Without going any further, we are creating huge mountains of garbage thanks to (or because of) the solar panels cheap. Now, as in any other decision-making, it is time to weigh the pros and cons and compare them with alternatives to have some perspective and here, solar energy does not fare so badly.

Damn (blessed) cheap solar panels. The generation of waste from solar panels is a reality that goes hand in hand with the deployment of solar energy. Between 2020 and 2024 the number of solar panels that have gone to waste has multiplied by four according to IRENA reports: from 220,000 to 900,000 tons and be careful because by 2050 have already estimated that the figure will be 250 million tons.

The reason? Although their useful life is 25 – 30 years, they are replaced before the end due to incidents such as storm damage or manufacturing defects. In short: replacing is cheaper than repairing.

In perspective. But the moment of truth comes from an estimate: the actual waste per megawatt hour of electricity generated. A current standard solar panel weighs about 20 kg and over its 25-year lifespan in moderate sunshine generates about 10 megawatt hours of electricity. The calculation is simple: it is equivalent to 2 kilograms of waste per megawatt hour and is similar to that offered by recent research published in Nature Physicswhich aimed at 1.7 kg/megawatt hour.

And now let’s face it against two energy rivals: coal and gas, two fossil fuels that continue to be behind the planet’s electricity generation. coal plants generate between 80 – 100 kg per megawatt hour. And that’s not to mention the 950 kg of carbon dioxide per megawatt hour emitted in combustion. Gas is slightly better: emits 450 kg of CO₂ per megawatt hour generated and no ash generated. But the difference is abysmal compared to the waste from solar panels. In a table on energy generation it is better seen, as this one from Clean Technica:

An abysmal difference. That is to say, we are talking about that considering the megawatt hour of electricity generated, a solar panel produces 2 kg of solid waste for about 90 kg of ashes that lead to an emission of 950 kg of CO₂ under the arm for coal and for gas, about 450 kg of CO₂ emitted. Electricity generation plants based on fossil fuels generate continuous and massive atmospheric pollution compared to 0 from solar panels and if we talk about solid waste, coal substantially surpasses it.

Not only the quantity, but also the quality. It has already been made clear that the amount of waste is substantially lower, but it is also worth mentioning how harmful this waste is and its consequences. To the remove a solar panel We find a frame made of aluminum, silicon, glass and some plastic, which although technically can be mostly recycled, in practice they are not recycled circularly. It is true that there are panels with traces of heavy metals such as lead (solders) or cadmium in thin film panels, but also that the EU counts with management programs for this waste. And the solar panels do not emit pollutants while they are operational.

Coal ashes have a list of traces fearsome: in addition to lead and cadmium there is arsenic, mercury, selenium, uranium or thorium. This cocktail is a risk to health and the environment due to inadequate management or spills. There is no need to talk too much about carbon dioxide emissions: they are behind the global warming. Coal combustion alone generated 15 gigatonnes of CO₂ between 2020 and 2024, according to analysis by the Global Carbon Project. This another study from the British Medical Journal relates air pollution from fossil fuels to some five million premature deaths last year, mainly respiratory diseases, cardiovascular diseases, and strokes.

Solar energy waste is not the problem. Clean energies are not perfect and their operation involves a series of challenges. As we have seen, in the EU in fact recycling infrastructure already exists which currently manages to recover up to 95% of these (the WEEE directive establishes a minimum recycling of 85% of the modules) in consolidated, scalable processes and result in small, manageable and moderately harmless final waste. With the data in hand, it is substantially clear that yes, waste from solar energy exists, but viewed from the perspective of current energy needs and the sources that provide it, they are not the problem at all.

In Xataka | The dark side of solar energy: we are creating a 250 million ton mountain of garbage

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Cover | Anders J