Winning Solar Car Technology
A mix of satellite-grade solar cells, good batteries, a new motor, and a little luck
The race stats are impressive: 3000 kilometers over four days on zero gas, zero emissions, and an average speed of 100 kilometers per hour. That's how Japan's Tokai Challenger solar car came in first at the 2009 Global Green Challenge in Australia on 29 October.
In choosing the technologies to make the Tokai Challenger, it opted for the best available, granting sponsorship rights in return.
For solar power, it turned to Sharp Corp., which supplied compound solar cells used to energize space satellites that boasted a conversion efficiency of 30 percent, considerably higher than the 20 percent efficiency level typical of even advanced crystalline-silicon solar cells. The compound materials enable these cells to absorb more of the available light spectrum than silicon but are more expensive to make.