Solar energy is made possible by the photovoltaic effect, a process that converts light (photons) to electricity (voltage). First identified in 1954, this discovery led scientists to create photovoltaic (PV) cells using silicon, which capture sunlight and make solar-generated electricity possible.

Solar cells were initially used to power space satellites as well as smaller items like calculators and watches. But refinements in the technology brought about individual solar PV systems used to power homes and businesses. Utility companies also began using PV technology for large power stations.