Trying to think systematically about electricity, I am making a list of all the basic ways it can be produced. Here is what I have so far:
- Moving magnetic fields: this is how generators work and, in reverse, electric motors.
- Photons hitting metal: this is how photovoltaic panels (PV) work.
- Materials vibrating, or stretching and compressing: see piezoelectricity.
- Chemicals reacting: as in alkaline batteries and fuel cells.
- Temperature differentials: as in themocouples.
- Exotic options: betavoltaics, thermionic conversion, magnetohydrodynamics, and thermophotovoltaics.
Most of our power plants are of the first kind, using kinetic energy from falling water, wind, or hot water boiled using nuclear or fossil fuels. There is a smattering of PV capacity around, and wave power stations might eventually use piezoelectricity. Chemically generated electric current has niche applications and thermocouples are used along with radioactive materials to power some satellites.
Are there any basic forms I am missing here? Are any of these actually manifestations of the same phenomenon?