Hi Volvo,
It really depends on what you are going to call differing parts of an entire energy system. If you look at as a complete system, Hydrogen is the basis of it all.
You say "Hydrogen is not an energy source at all, rather it is a energy carrier, and a poor one at that. "......... I think Hydrogen can be both. It will depend on how you define your objectives. Nearly all RE energy comes from Hydrogen. Most RE energy "sources" owe their very existence to the sun and the hydrogen conversion going on in it both now and millions of years ago.
It would seem that fossil fuels are really only condensed sunlight , water and co2. If it is done now, then it's biodiesel, if it was done millions of years ago, it's petroleum fuels, or coal. If it's wind or hydro, it's really recent sun energy, captured as pressure gradients, or condensed vapour, pulled out of the oceans by the sun... again and again.
It would follow that a most RE energy sources owe their very existance to the energy from the Hydrogen reactions in the sun.... the RE sources are really only storage mediums (fossil fuels) or active/passive carriers of kinetic or potential energy. It would seem that hydrogen is the source of fuel for these reactions.
There are other RE sources that are not hydrogen driven, and they are.. tidal power, which derives it's potential from the gravimetric and rotational interactions between the sun, moon and earth, and so is in a truly seperate catergory, and geothermal... from nuclear reactions below ground.
The only other energy sources on this planet that I can think of that are not dependent on Hydrogen reactions from the sun, are those from heavy element nuclear reactions.
These non sunlight energies give rise to RE in the form of geothermal energyand tidal energy.... it is interesting that both these systems are really not infinite. The earth is slowing down it's rotation, and the earth will cool down eventually.
Nuclear : It could be noted that even these heavy elements (U238 etc) derive their origin from hydrogen. All the elements that make up the earth have come from the debris of dying stars.... driven by hydrogen initially. All elements of atomic weight above iron will have had their genesis from super-nova (exploding stars). So geothermal and heavy nuclear reactions come from other stars (hydrogen driven), and all other sources of energy (except tidal) comes from the hydrogen economy of the sun.... every thing else we derive energy from is really only a carrier of that effused energy.
So what now.....
We can use Hydrogen as a carrier, just as we use petrol. It is as you have pointed out, not very efficient to use power from RE to convert h20 to h2 and o2, and is more useful to use the power directly...... provided it suits our purpose. Some here use petrol or diesel to charge their batteries.... poor conversion indeed, but it suits them...... thats what counts.
So I contend that hydrogen can be both a source, and a carrier. Fossil fuels can only be a carrier (potential energy stored in chemical bonds) of past energy from the sun. Re energy sources are really only forms of kinetic energy (wind) or radiation energy (heat and solar power cells, plant and vegatable matter). Geothermal is potential energy stored from previous steller explosions, and tidal is kinetic energy derived from a potential energy stored as rotational mass. The current crop of nuclear power devices are in the same catergory as geothermal, but harvested differently.
clear as mud as always...........oztules
