It’s been almost a year since I wrote about Stirling engines, and how heat can be transferred to a system and converted to do mechanical work. A Stirling engine works this way: you have two chambers communicating with each other: one that is being heated, and one cooling the hot air. The temperature difference between these two move a piston, doing mechanical work. The efficiency of Stirling engines is not dazzling at first sight, but it can be improved by using certain materials and shapes.
Dean Kamen, the inventor of the Segway, has just released to the public a modified electric Ford Th!nk, hacked in his DEKA labs. DEKA is his company located in Manchester Millyard, UK. Kamen’s modified electric car has a Stirling engine onboard, into the trunk. He uses the stirling engine mainly to defrost and heat the car, because the systems doing that are huge power consumers. “You’re running a pure electric, which is enormously cheaper to operate and enormously more environmentally friendly,” Kamen explained to unionleader.com. “It’s the world’s first Stirling hybrid electric car”, he also said.
But the Stirling engine is not only used to defrost your windows or heat your car, it can also recharge your batteries with a higher efficiency than the diesel engine has. That why Kamen calls his Stirling engine “an insurance policy” for the electric car. Kamen even showed off his state registration for his new car, listed as a 2008 DEKA Revolt. “I’m a car manufacturer!” he grinned. “It’s so exciting!”
The beautiful part with the Stirling engine is that is can use any available heat, for instance if you have diesel, it will burn diesel. If you have gas, it will burn gas. I’m sure that it can, at least theoretically, be adapted to burn anything, from wood to plastic bags – the only condition is to burn them as cleanly as possible.
A norwegian business group is interested in Kamen’s hybrid Stirling car, willing to invest in it and have it developed for the market.
It’s interesting to see the until now toy engines being brought to “reality” and installed in a normal car. I’ve always wondered how did Dr. Brown, from “Back to the future” could fuel his future flying car from “Mr. Fusion”, out of anything in Marty’s recycle bin. Pretty neat, isn’t it?