Power From Heat | Green Energy News

September 4, 2005 – Vol.10 No.24

POWER FROM HEAT.

Anyone who has a conventional, tank-type, propane or natural gas hot water heater in their home more than likely is the proud owner of a thermoelectric device - a device that will convert heat directly into electricity.

In a hot water heater the device is a thermocouple. It’s a safety device. It’s installed so that the flame of the pilot light burns over it. The heat of the flame causes the thermocouple to generate a small amount of electricity. As long as the pilot light is burning the power from the thermocouple will keep the gas valve open and allow the hot water heater to make hot water. Should the pilot light go out for some reason gas (or propane) will be shut off.

The science behind thermocouples goes back to 1822 to Estonian scientist Thomas Seebeck who discovered the principle by accident. The principle is that when heat is applied to the junction of any two types of metal, electric current will result. Some metals work better than others.

Thermocouples have been used in a variety of products for decades. They’re simple, cheap and reliable.

Now, add nearly 200 years to the development of thermoelectrics, materials, and most recently add nanotechnologies to that science and what do you have? Better materials than in 1822 that could lead to a wide array of thermoelectric devices. Think solar thermal energy converted directly to electricity. Or, heat from the smokestack of a power plant converted to electricity.

All of the above, and others, may be possible. But cars may come first.

The U.S. Department of Energy (DOE) has given BSST LLC the go-ahead to proceed with Phase 2 of a $6.3 million program to build a practical thermoelectric system that will convert waste heat in engine exhaust to electricity.

Depending on how good the technology gets, the electricity could be used for anything from charging a conventional vehicle’s battery to supplying power to a hybrid electric drive system. In any case fuel would be saved.

The company is leading a team of heavy hitters to develop the technology including BMW, the University of California at Santa Cruz, Purdue University, DOE’s National Renewable Energy Laboratory, and the Jet Propulsion Laboratory/California Institute of Technology among them.

Phase 2, which is expected to take a year, will include building sub components and supporting processes such as developing materials and creating manufacturing processes. Phase 3, if Phase 2 is successful, will be to build a full system prototype.

The whole research and development process may take a few more years. In the mean time think of all the devices around you that expel waste heat. How much of that heat could be recovered and put back to work?

Visit BSST at http://www.bsst.com/