Unlike the fossil fuels that still provide the bulk of the U.S. power supply, solar panels generate electricity with no air or carbon pollution, no ash or other waste products, and no inputs other than sunlight.
While the manufacturing of solar panels, like all other energy devices, involves emissions, PV electricity generation itself:
- generates no carbon dioxide or other heat-trapping gases that contribute to climate change
- produces none of the other harmful emissions or wastes associated with coal power, such as mercury, sulfur dioxide, nitrogen oxides, lead, and arsenic
- creates none of the long-lasting waste or environmental risks associated with nuclear power
- avoids the environmental risks associated with natural gas, including potential water pollution during extraction
What’s more, rooftop PV electricity generation involves little to no water. That stands in contrast to almost all power plants that make electricity using steam. These include coal and nuclear plants, many natural gas plants, and some other renewable energy facilities, which depend on water for cooling. That dependence can cause problems when cooling water becomes too scarce or too hot. PV systems, in contrast, require no water to make electricity.
In most cases, solar panels also have no impact on wildlife because they are typically installed in already built environments. Solar panels do involve materials that need careful handling while the panels are manufactured and at the end of their useful lives. As with computer chips, manufacturing solar panels involves a range of hazardous materials—for example, hydrochloric acid, sulfuric acid, nitric acid, and hydrogen fluoride. Non-silicon solar cells, including ones made from gallium arsenide, copper-indium-gallium-diselenide, and cadmium telluride, contain more toxic materials than those used in traditional silicon cells.