Solar panels work by capturing energy from sunlight. They contain many small cells, usually made of silicon, which act like tiny electricity generators. When sunlight (photons) strikes these cells, it knocks electrons loose, creating a flow of direct current (DC) electricity through the photovoltaic effect. Because most homes and businesses use alternating current (AC), an inverter is used to convert the DC electricity into usable AC power. Solar power is incredibly useful because it’s a clean energy source that doesn’t produce greenhouse gas emissions while operating, taps into the renewable power of the sun, and can help lower electricity costs.  

Following early private inventions, US public institutions significantly advanced solar technology. The Department of Energy (DOE) has funded extensive research, notably establishing the National Renewable Energy Laboratory (NREL) in 1977, which remains dedicated to improving solar efficiency and affordability. Many public universities across the country also conduct vital, often DOE-funded, research in materials and engineering. Key contributors include institutions like Arizona State University, known for its dedicated solar programs, the University of Delaware with its early Institute of Energy Conversion, and major research hubs within the University of California system. This sustained effort, combined with falling prices, has led to explosive growth. In recent years, solar power has consistently accounted for a massive portion, often around half, of all new electricity-generating capacity added to the U.S. grid each year.