Solar Cars

by JOHN BELL

With zero emissions, solar cars present a sunny solution to eco-friendly car buyers. It also makes good sense to develop a green car technology that doesn't call for a complicated infrastructure or any type of fueling station. What could be easier than using an already existing solar energy source from the Sun, right? If it were only that simple, we'd probably already have done it. In spite of universities and corporations building solar cars every year for the past 20 years for the annual Australian World Solar Challenge solar car race, we're not quite there yet.

How do they work?
A solar car is really an electric car powered by solar energy. Photovoltaic (PV) cells in the form of solar panels convert sunlight into electrical energy. The process generates heat, which is converted into electrical energy and stored in an on-board battery. The battery serves the same basic purpose as a gas tank on an internal combustion car.

In spite of the great bounty of sunshine there for the taking, solar car technology is elusive. The solar electric power source needs a lot of PV cells, which are expensive, and the efficiency level of PVs is estimated to be only 10% to 15%. These are daunting challenges facing engineers, and it's more likely a hybrid solar with another fuel source is the only viable option in the near future.

Are there any solar cars out there?
French manufacturer Venturi says their solar electric AstroLab hybrid concept car yields an improved PV cell efficiency level of 21%. It's not exactly a family car with its 2-seat tandem cockpit configuration, but it's one possibility. The Hungarian manufacturer Antro has designed a solar gas-electric hybrid scheduled for production in 2012, and Tesla Motors has an electric car that can be recharged with solar power with 2009 models available in the U.S. and Europe.