British company Intelligent Energy has produced a prototype fuel cell-based motorcycle, the ENV (Emissions Neutral Vehicle), which it revealed in London.With a top speed of 50 mph, which it takes a leisurely 12.1 seconds to reach, the ENV won’t be leaving Harleys or Ducatis in the dust any time soon. But its problem isn’t just a lack of power,it’s a lack of noise.Its expected price is somewhere below $10,000,and it should be available in about 18 months.  ridingsun