[Aedo]

Think of the examples in nature. Plants don't need that much energy to separate hydrogen. This isn't electrolysis. The membrane would be enzymatic. The return wave from the MFD would only serve to turn the membrane on or off. Yes, you would need to input new energy into the system as you went along but not nearly the amount you are suggesting.

Doesn't matter how you do it, it still takes the same amount of energy - you don't get something for nothing, or even something for a little, if you did it would be perpetual motion. By the way what makes you think that plants don't use as much energy as any other system?

The laws of thermodynamics apply to plants as well as people - the second law of thermodynamics - you can't break even (in Monte speak) states that you must put more energy into a system than you can get out. This is always the case.

[Keith_McClary]

So you can almost think of cars as giant heaters with a side effect of moving the vehichle forward.

Up north we are happy with the giant heater - the side effects are a bonus.

[Guest]

You cannot easily replace hydrocarbons with hydrogen.

The reason is: Most of the energy released from the oxidation of hydrocarbons comes from the carbon. The hydrogen does not contribute much.

When you burn hydrocarbon fuels, you burn the product of centuries of energy storage. HC's serve as a battery that takes a really long time to charge. The sun is the charger.

Most of the energy that a plant takes in is turned into carbohdrates. There are the energy storege for the palnt. Most of the energy is in the carbon portion of the equation.

I've worked through these calculations. I'd be happy to do it again. It takes energy to heat the fuel. More energy to break the C-h bonds. Energy is released form the C_O reaction. More from the CO_CO2 reaction. More from the 2H_O reaction. Most of the net energy comes from he carbon. Painful Fact: This is stored solar energy.

There are no subsitutes, in terms of energy density, for hydrocarbons.

Actually there is: Plutonium. Maybe. THis is an economical solution for a billion dollar satelite

[evilgenius]

I didn't say anything about not using what is basically free in the environment around you to make up the difference. This is about how much energy the user has to come up with, not about the total energy being used to separate the hydrogen from the oxygen.