Turning heat from a car’s exhaust into power
Both General Motors and BMW plan to test devices next year that will convert an engines excess heat into electricity. Research into thermoelectrics, the science of using temperature differences to create electricity, couldn’t come at a better time as high gas prices accelerate efforts to make vehicles as efficient as possible.
GM researcher Jihui Yang said a metal-plated device that surrounds an exhaust pipe could increase fuel economy in a Chevrolet Suburban by about 5 percent, a 1-mile-per-gallon improvement that would be even greater in a smaller vehicle. According to GM only about a quarter of the total energy from gasoline is used to actually turn the wheels, while 40 percent is lost in exhaust heat and 30 percent is lost through cooling the engine. That means about 70 percent of the available energy is wasted. Reaching the goal of a 10 percent improvement would save more than 100 million gallons of fuel per year in GM vehicles in the U.S. alone.
Source: Associated Press