It’s nice for a toy, but difficult to understand when it comes to explaining the true greenness of this invention. A stirling engine-powered toy just hit the market recently, combining a 194-year-old engine concept touted today for its fuel flexibility with solar power-the baby that modern science wants to grow.
The 200-dollar toy consists of a parabolic mirror that focuses light onto a heat exchanger, which causes the air inside it to expand and drive two pistons. Once the mechanical work is done, the air in the second piston cools, is transferred to the first one and the cycle starts over and over again.
The stiring engine powers a NiMH battery, which in turn powers the electric motor. As inefficient as it may sound, it’s an option if you’re stranded in the middle of nowhere and want to make yourself a solar powered vehicle to reach civilization. Or you can choose some solar panels, they’re more fit to that.
Dean Kamen had some plans of building a stirling engine-based scooter, I don’t know if he succeeded yet.
Anyways, the stirling engine toy is interesting at the part of teaching your kids what these engines are and how they work (you can even make one from a soda can), but the thing is too expensive.
Nevertheless, if they sold it for $50, it’d be the perfect toy. Otherwise, it looks totally pointless green to me, since you can only play with it for 5 minutes after waiting three hours in the Sun. Full Sun.