A Fuel-Cell Motorcycle With Portable Power Riding the ENV is more akin to skiing or sailing than cruising on a 176-pound motorcycle. It’s emission-free and as quiet as your computer. At the heart of this hydrogen-powered machine is a fuel cell, dubbed the Core. It breaks down hydrogen into electrons, which power the electric motor, and protons, which interact with oxygen taken in through the ENV’s nosecone and are released as Earthfriendly water vapor and heat. The Core is detachable, so it can power a small house or boat. Available in late 2006. $6,000 (I presume that US$)