One Way or Another, Most of Our Electricity Comes From Solar Power
Key summary
Electromagnetic induction: a changing magnetic flux through a loop induces an oscillating voltage, the basis of alternating current.
Generators increase output by using many turns in a coil or by rotating magnets relative to a stationary coil; relative motion produces electricity.
Most methods of producing electric power use the same magnet-and-coil principle.
Mechanical drivers include wind (large blades turning a rotor), flowing water in hydroelectric dams, and steam turbines powered by heat from coal, oil, natural gas, geothermal sources, or nuclear fission.
Solar panels (photovoltaic cells) convert light directly to electricity with no moving parts; solar radiation weakens with distance from the Sun and is partly absorbed or scattered by the atmosphere; the article discusses solar flux at the equator.
