Amount Of Energy Required For Extracting Hydrogen From Water.

[Kratos]

Can someone tell the amount of energy required to extract hydrogen from water through electrolysis.

[Buenchico]

http://physics.stackexchange.com/questions/24624/water-electrolysis-calculations

[ToraToraTora]

it's the twenties, well known calc! basically why hydrogen is 400 times less efficient than the fossil fuels used to generate the the electricity (20% of what is used to gen it) multiplied by the amount of energy you get from the hydrogen after you strip it from the water(20% again give or take) so you can get 400 times more energy from 1lb of coal than you can get of you use it to generate electricity and then use that electricity to strip the hydrogen from what it is attached to, usually oxygen. Did someone tell you that the hydrogen fuel cell was efficient? Oh dear.

[ToraToraTora]

you see hydrogen is mostly attached to something else, on earth, usually oxygen, ie water, the ash from combustion of hydrogen. That's why electric cars are 5 times less efficient, than those powered by fossil fuels. You are better of converting to coal fired steam!