We've run across a few
, 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.