Photovoltaic (PV) modules make electricity from sunlight, and are marvelously simple, effective, and durable. They sit in the sun and, with no moving parts, can run your appliances, charge your batteries, or make energy for the utility grid.
A PV array is the energy collector—the solar “generator” and does so via the photovoltaic effect. Discovered in 1839 by French physicist Alexandre-Edmund Becquerel, the photovoltaic effect describes the way in which PV cells create electricity from the energy residing in photons of sunlight. When sunlight hits a PV cell, the cell absorbs some of the photons and the photons’ energy is transferred to an electron in the semiconductor material. With the energy from the photon, the electron can escape its usual position in the semiconductor atom to become part of the current in an electrical circuit.
When we consider the true cost of energy, we need to look at the big picture, not just the rate on the utility bill. Conventional fuels have real social, environmental, and economic impacts. There are annual and cumulative costs that stem from all of the pollutants (airborne, solid, and liquid) emitted from mining, processing, and transporting fossil fuels that impact our public health and the environment. Electricity derived from coal and natural gas will never be able to outweigh the energy and continual resources required to produce it. Unlike conventional energy sources, PV systems produce clean electricity for decades after achieving their energy payback in three or fewer years—this is truly the magic of PV technology.