Keeping the home fires burning

Some utilities and thermal researchers are devising thermoelectric and thermophotovoltaic technologies to convert furnace heat to electricity and keep home heating systems functioning during extended power failures. Storms that damage power lines often leave homes without heat, since the electricity supplied to furnace blowers is cut along with all other electricity. One case in points is the March 1991 ice storm that left nearly 200,000 Rochester Gas and Electric Corp. customers without electrical power, some for up to two weeks. This led the Rochester, N.Y., utility, RG and E, to search for an independent power source that could provide homes with heat during prolonged outages. RG and E funded development of a continuous gas furnace by the GE Research and Development Center in Schenectady, N.Y., that would keep its customers' homes heated and provide some electricity during power outages. Since natural gas lines are rarely interrupted during a power outage, the furnace is still a potential source of heat, but only if there is some way to supply electricity that is independent of the grid, said Bruce Snow, manager and chief engineer of the technical services division at RG and E. The electricity would power the furnace blower, which blowsmore » hot air through air ducts, or run the motor that pumps water through a piping system to keep the house warm. Such a thermoelectrical system involves heating the two junctions of thermocouples, which are made of dissimilar wires, at two different temperatures in order to create electricity. A newer technology, thermophoto-voltaics, also converts heat to electricity. In this process described here, the heat causes an emitter to radiate a wavelength of light, which is converted into electricity by a photovoltaic unit.« less