A gas-powered bike? We've got those. They're called motorcycles. Start slapping combustion engines onto your average pedal bicycle and you're taking one step backward for nature, and one giant backflip for mankind. It can reportedly hit speeds of up...

Cool Earth’s inflated solar concentrators may be the lightest power plants around. Looking like a biggie version of those shiny helium balloons you might see at someone's birthday party, the concentrators weigh just 20 pounds and, tethered to lightweight...