Turning Heat into Power

 Posted by at 10:05 pm  Gadgets
Jan 262008

The Discovery Channel reports on a new form of power generation that can convert heat into electricity, apparently at scale.

The inventor of this new system is Lonnie Johnson, who also happens to be the inventor of the “Super Soaker” squirt gun.  Johnson’s new focus on electromechanical systems appears to be underwritten by the success of the water toy.

At the core of Johnson’s Thermoelectric Energy Conversion System (JTEC) is a membrane covered with electrodes.  Under thermomechanical stress (heat), the electrodes manage to force hydrogen atoms through the membrane, stripping the electron off the hydrogen in the process.  Any time you can physically separate an electron from an atom, you have electrical current. If you can do it a lot and continuously, then you have a good chance of producing a lot of usable electrical current.

The cool part about Johnson’s engine is that it uses mechanical energy (heat oscillation) to rip the electron off the hydrogen.  The Discovery article also notes that while the system uses hydrogen, it does not “burn” or consume the hydrogen – it uses a fixed amount of hydrogen circulated in a continuous cycle of electron detachment and reattachment (circulating between anode and cathode and back, presumably).

Discovery notes that current solar panels convert sunlight into electricity at about 30% efficiency.  (In the lab, maybe.  High-end commercial PV panels run more in the 20% efficiency range, and mass-produced cheap panels are lucky reach 10%)  Johnson’s heat engine design could reach an efficiency as high as 60%, if the system can be built to handle higher operating temperatures – about 3 times higher than the current working prototype’s 392 degree F operating temperature.

Well done, Mr Johnson!  I look forward to hearing a lot more about this over the next year or so.