If you live in a city, chances are you've seen people tooling around on "electric bikes," battery-powered scooters that can reach speeds of about 30 km/h. But you've probably never seen an e-bike like this one.
The Solar-Cross is a one-off solar-powered e-bike built by Squamish, B.C.'s Terry Hope, a former schooner engineer. He started with a used full-suspension mountain bike, and added 32 solar cells hooked up to a 1,000-watt motor. The result? A hybrid solar- and pedal-powered bicycle for about $700:
The total rig weighs about 21 kg — not much more than many mountain bikes — and with enough light, the solar panels can power Hope up hills, although not very quickly. The real advantage of the solar cells is as a power assist. "If I was pedaling the bike at 40 km/h," he told Strombo.com, "I could theoretically utilize the approximately 100 watts of solar energy from the panels to make the pedaling a bit easier."
Next year, Hope says, thinner solar cells packing higher efficiency will hit the market, allowing him to use about half as many panels to get the same result. And if you'd like to build one of these yourself, Hope is considering putting together a solar panel kit for late next year.