Super Soaker inventor touts solid state heat-2-leccy

A former NASA engineer, most famous for inventing the noted "Super Soaker" squirtguns, may be on the track of a radical new energy technology which could have important implications for power generation.

Popular Mechanics reports that Lonnie Johnson, late of NASA's Jet Propulsion Laboratory, believes he may be able to hugely increase the efficiency of converting heat into electricity. Since becoming rich on Super Soaker licensing, Johnson has used his cash to develop and patent various new technologies.

The latest of these he has dubbed the Johnson Thermoelectric Energy Conversion system (JTEC: technical details and Flash diagram from Johnson's company here). It's a "solid-state engine" which uses temperature differences to drive a closed hydrogen loop in which protons move across a membrane. This generates electricity, drawing energy efficiently from the heat source. Johnson thinks it will easily scale up to the megawatt range.

The US National Science Foundation believes that JTEC has potential, and has funded its development.

“It’s like a conventional heat engine,” the Foundation's Paul Werbos told Popular Mechanics.

“It still uses temperature differences to create pressure gradients. Only instead of using those pressure gradients to move an axle or wheel, he’s using them to force ions through a membrane. It’s a totally new way of generating electricity from heat.”

As Pop Mech noted, JTEC could be a big boost for "solar thermal" power generation. It might double the efficiency of plants which currently focus the sun's heat using mirrors to drive generators. (The founders of Google, who think that solar thermal is the way ahead for low-carbon power, will no doubt be interested.)

The article goes on to say that "solar [is] more expensive than burning coal or oil. That will change if Lonnie Johnson’s invention works..."

That's untrue, of course, as coal- or oil-burning generators also convert heat into electricity, with the same sort of low efficiency as solar-thermal does. Any benefit offered by JTEC would apply equally to fossil fuel power stations, leaving solar lagging behind as before.

If JTEC works it would also be a big boost for nuclear, gas, and all other heat-based power technologies.

It would be unlikely to benefit wind, tide or solar-photovoltaic, however, making these technologies significantly less economically competitive than they are now.

So the kit would be green, in that it would significantly reduce energy waste and thus cut down on fossil fuel use. But many orthodox greens would be depressed at the economic torpedoing of their favourite power technologies.

Nobody needs to get too excited, though: JTEC remains a long shot for the moment. ®