Lonnie Johnson, the inventor of the Super Soaker, has invented a device that can generate electricity from heat differentials (a thermoelectric generator).
Johnson says it has the potential to be the best-ever method of converting solar energy into a form that we can use. Among the potential applications are at utility-scale solar thermal farms and for plug-in hybrid vehicles, in which the device would use waste heat from the car’s internal combustion engine to help power the car’s electric motor.
Johnson says a prototype of the heat engine, called the Johnson Thermoelectromechanical Energy Conversion System, or JTEC, will be ready in a few months. It could, ideally, be 78 percent Carnot efficient. But what sets JTEC apart is its all-solid-state design. The lack of moving parts such as turbines and pistons eliminates nearly all of the parasitic losses that, in machines like an automobile engine, greatly lower efficiency.
In contrast, photovoltaic devices have net conversion efficiencies in the teens and thermionic (or thermoelectric) chips reach only a little higher than 20 percent of Carnot when converting heat to electricity.
“Johnson has opened up a fundamentally new pathway to generate electricity from heat,” says Paul Werbos, program director for power, control, and adaptive networks at the U.S. National Science Foundation (NSF). Werbos, an IEEE Fellow, says the NSF is funding Johnson’s heat-engine research because of the strong chance that it could cut the cost of solar power in half. Werbos acknowledges that the product’s development is still at an early stage where unforeseen problems might creep in. “But I don’t see any showstoppers,” he says.
Find out all the gory details in this IEEE Spectrum article.
Johnson’s page for JTEC, Johnson Thermoelectric Energy Conversion System.
In his hometown of Marietta, Georgia, February 25, 1994 was declared “Lonnie G. Johnson Day” in his honor