It may also prove possible to extract hydrogen from the cold traps at the poles of the Moon.

Unfortunately, the atoms are so firmly locked that present methods use more energy to extract hydrogen than can be produced by the fuel.

Nevertheless, as you say, "present methods" use more energy to extract hydrogen from water than can be obtained from it later as fuel.

In order to extract hydrogen from these compounds, you have to exert energy.

Certainly, fuel cells that use renewable resources like wind and solar power to extract hydrogen from water promise America a safe, clean energy solution.

They began by constructing a furnace, then extracting hydrogen.

For example, the Energy Department plans to spend $1 billion over 10 years on a project to extract hydrogen from coal.

The other firm can jury-rig some means of extracting hydrogen from water.

But other forms eventually arose which were able to extract hydrogen from a very much more widespread source - water.

Every green plant on the earth is a solar hydrogen machine that extracts hydrogen from water (H0) with the energy of the sun.