BMW officially announces the BMW Hydrogen 7 {Autoblog Green}

Sep 12th 2006 2:57PM If the hydrogen is produced by electricity generated by hydro-electric power then the hydrogen engine is indeed "green" because the car then runs indirectly on solar power, and because CO2 is not produced, just water vapour out of the exhaust, returning the amount of water use to produce the hydrogren. However, hydroelectric power generation is limited and damages the planet because of the dams and flooding. A better, sustainable source of power would be by blowing membrane mirror bubbles in Space then coating them and dividing them and using them to concentrate sunlight on power generators which would then beam the electric power down to Earth. The vacuum of space is ideal for electricity generation because there is no air convection of heat between the hot and cold parts of the generators, thus allowing a very large difference in temperature thus an exceptionally efficient Carnot cycle.