Researchers estimate that more than half of the energy generated in the U.S from vehicles, machinery and heavy equipment is wasted as heat when it escapes into the air. Gang Chen, the Carl Richard Soderberg professor of power engineering and head of MIT’s Department of Mechanical Engineering, and his colleague Zhifeng Ren of the University of Houston, have found a way to utilize this waste heat.
GMZ Energy, a company founded by Chen and Ren, has produced a new thermoelectric generator (TEG) that uses waste heat discharged by vehicles to create powerful electricity.
“In a TEG, electricity is generated when heat enters the top of the module, and then moves through the semiconductor material — packed into the TEG — to the cooler side. The resulting motion of electrons in the semiconductor under this temperature difference creates a voltage that’s extracted as electricity,” an article on designfax.net explains.
Usually in TEGs the vibrations of the material causes heat to leak from the hot to the cool side; however, GMZ’s method delays heat leakage, researchers say. This delay in heat leaking through the generators contributes to an increase in productivity by 30-60 percent.
The TEG can endure abrasive temperatures, both hot and cold, ranging from 600 degrees Celsius to 100 degrees Celsius. Researchers note that with this slope of 500 degrees, a module that’s 4 centimeters square can produce 7.2 watts of power. This amount of power could fuel a car’s entire electrical system and would greatly decrease fuel costs. GMZ Energy is currently working to improve the fuel economy in vehicles by 25 percent and hopes that soon their knowledge of TEGs can be applied to cars and improve overall efficiency, say researchers.
Not only will this discovery improve GMZ, but it will help to evolve the entire market.
“Thermoelectrics isn’t something you can see. It’s not as recognized as a battery or photovoltaic cell. The whole field needs successful products on the market to sustain, inspire, and stimulate innovation,” Chen said. At the end of the day, Chen sees GMZ as “a big step toward his goal of helping create a more energy-efficient world.”
