Where Does Electric Energy Come From?

Though a nuclear power plant, a coal-fired plant, and a wind turbine may look different, they all make electricity the same way: by turning a generator. Electric energy comes from a handful of sources. It can be produced from a chemical reaction, from electromagnetism, radiation or light. You can make electricity by pulling scotch tape from its roll. These are all fundamentally different processes. In 2009, one of these is used to power cities; most have relatively minor roles.

Chemical

Batteries are a familiar way to produce electricity from chemicals. When you connect the battery to a circuit, chemical reactions create an electric current.

Atomic

The radioactive decay of some elements gives off radiation in the form of charged particles. This is used as electric power for deep space probes and pacemakers.

Electromagnetic

Household electricity comes from power company generators. In a generator, a copper coil moves through a magnetic field, creating current in the coil.

Triboelectric

When objects touch and separate, electric charges pile up in them. This is what's commonly called "static electricity," and is responsible for static cling and lightning.

Photovoltaic

When light shines on some materials, electrons move in them. Solar, or photovoltaic, cells are made of silicon and other light-sensitive elements. As long as the sun's shining, the solar cells produce electric power.

References

• How do electric generators work?
• How do photovoltaics work?
• How do batteries work?