is there truly any green energy?

i guess the truest green energy harps back to days of windmills and water wheels, where all the pats wee made from trees,

surely everything in the modern 'green' age is a trade off?

even if a car was capable of converting gases from the atmosphere what would it acheive? no doubt 1 billion cars, or however many there are, will one make a huge dent in the some gas or other and cause another global scare.

lets face it, we can all do our little bits, but unless there's some huge catastrophy that takes the world population to that of a few thousand years ago, and we all live in mud huts with no electric, no fossil fuels, etc, the planet will never again attain a level of true self sufficiency.

re the topic, this fuel cell thing, one thing i see no-one has mentioned is the cost of charging such a cell, the average fuel costs are high enough, but imagine dumping megawatts of electricity every year into a car, would it be any cheaper than filling up with petrol / gas every few hundred miles?

while it's an interesting subject, i don't think i'll be truly impressed until someone comes up with a vehicle which utilises perpetual motion / charging, ie, some kind of alternator which generates more power than the car uses.