The thermoelectric effect can produce small amounts of electricity from almost any source of heat, but its low efficiency has so far limited its uses. A team has now found a simple way to make one thermoelectric alloy more efficient.
When two ends of a stick of a thermoelectric material are exposed to different temperatures, a voltage appears. The electrons in the stick act like the molecules in a gas: Just as gas expands when heated, the heated electrons move from the hotter side to the cooler side. The resulting voltage can create current.