All right, so maybe some of the homebuilt solar-powered cars that we've shown here in the past aren't the best-looking contraptions. Give then this, though: they certainly are useful. The latest example was made by a California man named Brent Hatch, who decided enough was enough when he got a $700 gas bill. With seven kids to drive to school and back along with record-high gas prices, it's easy to see why Hatch was fed up. His solution centers around a four-wheeled, pedal-powered bike that has been equipped with three roof-mounted solar panels. These provide electricity to a small electric motor. Maintenance charges have also gone down considerably, with the only real wear item being the vehicle's sole rear tire, which is powered. Perhaps it's not the most elegant solution we've ever seen... but it's hard to argue that it gets the job done. Watch a video of the machine in action here.

[Source: CBS 2 via Engadget]

We've run across a few solar-powered two-wheelers before, but this one, known as the Sunny Day, is a concept that makes some sense. Many bikers who are interested in the utmost efficiency already streamline their bikes, so why not coat that bodywork in solar cells? We're not certain how efficient the solar cells could be or how many the limited real estate would allow, but even a bit of electric-boost could be helpful to commuters. Additionally, the bike folds down, offering the cells a more direct look at the sun and easing storage issues. The Sunny Day bike was recently awarded Grand Prize win in the 12th annual International Bicycle Design Competition. We'd have chosen it, too.

[Source: Gizmag]

While it is not uncommon for electric bikes to have a front hub motor or for them to have batteries mounted on the rear racks, these are the first pair of wheels that I have seen with solar panels integrated into them. I think that the idea is pretty cool, and can't really think of another place on a bike where there is enough real estate for an effective amount of solar cells to be mounted. Wheels like these are likely a bit more aerodynamic, but could pose a bit of an issue if there are heavy side-winds. Still, with this bike you could pedal when the going was easy and engage the motor when the going gets tough - and all the while never need to gas it up or plug it in.

[Source: Therapy Products via Reuben Miller - thanks!]