Electricity From Pressure, Heat, and Light Pressure, heat, and light can be used to produce small amounts of electric current. These sources of electricity, while not significant on a large scale, have important applications in microphones, measuring devices, and security systems, among other users.
Electricity From Pressure If certain crystalline substances, such as quartz or Rochelle salts, are pressed between two metal plates, an electric force will be developed. At ordinary environmental temperatures, this force is in proportion to the pressure exerted. Electricity generated from pressure is used in phonograph pickups, microphones, and instruments used to measure variable pressures or weight.
