Thermophotovoltaics; September 1998; Scientific American Magazine; by Coutts, Fitzgerald; 6 Page(s)

Photovoltaics is a technology that typically transforms sunlight into electricity. Radiation from the visible part of the spectrum is, after all, abundant, nonpolluting and free. But photovoltaics can also provide useful amounts of electricity from infrared radiation-- that is, radiant heat generated by a source of energy such as fuel oil.

This lesser-known approach, called thermophotovoltaics, offers a major advantage in certain settings: a generator can operate at night or when the sky is overcast, thereby eliminating any need for batteries to store electricity. The technology is also preferable in some ways to conventional electricity-generating technology based on burning fossil fuels. Its efficiency--the percent of fuel energy converted to electricity--can be substantially higher than that of electric generators powered by natural gas or another fossil fuel. Moreover, a semiconductor- based thermophotovoltaic system can be designed to minimize pollutants. And because it contains no moving parts, it will run silently and reliably, requiring little maintenance.