Here's how it works: unlike a regular steam engine, which converts heat generated from burning coal into electricity, the JTEC uses heat to expand hydrogen atoms in one of the stacks, the report said. The expanding atoms split apart into electrons and protons. The freed electrons "travel through an external circuit as electric current," which can charge a battery, for example, while the protons end up combining with electrons on the other side to reconstitute the hydrogen, beginning the cycle anew.
Among JTEC's advantages, aside from its efficiency, are the fact that it's reliable and silent compared to an engine with moving parts. (Think of all those massive, clanking, hissing steam engines that still run nearly all of the power plants in the U.S., including coal and nuclear varieties.) The JTEC also uses hydrogen, and produces little waste as a result. It's roughly twice as efficient as a photovoltaic cell, which normally struggles to top 20 percent efficiency, and maxes out at around 30 percent in thermal power plants, the report said. Essentially, that means the JTEC is roughly as efficient as burning coal, with virtually none of coal's downsides.
Excerpts from ExtremeTech article Solar Energy Gains Steam—or Rather,Hydrogen, article October 14, 2010 By Jamie Lendino and November 2010 ATLANTIC MAGAZINE article Shooting for the Sun by Logan Ward; Image credit: Ben Baker/Redux