Originally published in The Environmental Magazine
Unlike fossil fuels, solar panels emit no carbon dioxide (CO2) into the atmosphere while generating electricity. However, they do have some negative effects on the environment. This essay provides a description of said effects, and compares the environmental impact of solar panels to that of coal and natural gas plants.
The creation of almost all solar panels begins with the mining of silicon, which is highly reactive. This means that it readily forms compounds with other elements. Due to this characteristic, ore containing silicon must go through an energy intensive purification process before use. This purification process takes place in arc furnaces, which use the heat from an electrical arc to melt raw materials. As the grid becomes increasingly powered by renewables, this aspect solar panels’ production process will become far greener than it is today.
After processing, silicon is combined with metals such as aluminum, gallium, indium, lead, and cadmium, and covered with glass or plexiglass, to create functional panels. Following transportation and installation, these panels enjoy a long lifespan of 25–30 years. Once this time has elapsed, the amount of energy they produce begins to decline. At some point, replacement becomes necessary.
While the individual components of panels are not inherently difficult to recycle, the process of separating them from one another can be somewhat tricky. Fortunately, several companies in Europe and the U.S. have risen to the challenge of developing reasonably effective techniques for recycling solar panels and their constituent parts. As more innovation takes place in the field of solar recycling, the efficiency of this process will rise even further, and its environmental costs will fall even lower.
Any negative effects that solar panels have on the environment during their functional years are either minimal (in the case of solar farms) or non-existent (in the case of rooftop solar). Although the installation of large scale solar farms in natural habitats will understandably alter the land directly underneath the panels, power companies can build them in deserts, or areas in which land has already been degraded. Such actions will greatly reduce their impact on natural habitat.
When compared to coal and natural gas, solar is the clear winner in terms of environmental impact. The best statistic to illustrate this fact is the amount of CO2 each respective energy generation technology releases into the atmosphere, per kilowatt of energy generated. The Union of Concerned Scientists (UCS) website estimates this ratio to be between 0.07 and 0.18(pounds of CO2 per kilowatt) for solar, between 0.6 and 2.0 for natural gas, and between 1.4 and 3.6 for coal. And again, these ratios will continue to improve for solar, as the energy used to process silicon comes increasingly from renewable sources. It is also worth bearing in mind the fact that the burning of coal releases many toxic compounds in addition to CO2 that can have significant negative effects on both public health and the environment.
If you would like to help accelerate the world’s transition to solar energy, there are many ways in which you can do so. One of the most obvious is by installing solar panels on your house, and or encouraging your friends to install panels on theirs. The energysage.com website is useful for determining how much money you could save by installing rooftop solar. For those of you looking to recycle old panels, check out the websites of solar recyclers like U.S.-based Recycle PV and the french company Veolia.