Monday, November 20, 2006

Pop Quiz: What two sources of energy account for nearly all the world's energy use?

Answer: Solar and Geothermal.

I’ve been thinking a lot about energy lately, and this is just a curious factoid I've been pondering. When discussing energy, careful people distinguish photovoltaic power from the more general term of solar, because really when you think about it, nearly all the energy we use is solar, except for the stuff that’s geothermal. Basically, there you can think of energy as coming in the form of 4 forces, the weak and strong nuclear, gravity and e&m. And I’m basically say it is gravity and the sun's strong nuclear as the source of everything.

Hydropower – Powered by the water cycle which is powered by the sun.
Photovoltaic – Directly solar powered
Ethanol and other Biofuels – From the plant matter that got its energy from the sun
Oil – From the plant matter that got its energy from the sun that was converted into oil by geothermal pressures.
Natural Gas and Coal - Ditto.
Geothermal – Well geothermal.
Wind – Powered by temperature gradients crated by the sun.
Fission – Powered from the energy stored in uranium atoms, which were created not by our sun, but the previous star of our solar system. So given that it is also powered by a star of our solar system, I’d say that’s also solar power.
Tidal – Actually, this is different as this is lunar powered, but no one really uses it so its ok.
Fusion – This is actually different two, fusion is powered from the hydrogen remnants of the Big Bang, but there are no real fusion power plants either, so I’m ok on this one for now.


James said...

If you consider fission to be derived from solar power, how is geothermal distinct? Everything ultimately can be traced back to star matter.

HoBs said...

yeah, i should be more clear. by solar, i mean akin to the power teat emanates from the sun, mostly resulting from the strong nuclear force, (The fusion going on in the core), whereas geothermal (like tidal) comes from gravity, which is not so solar. i mean, of course everything comes from the big bang, but that's silly.

Anonymous said...

But doesn't solar power come from fusion in the sun which comes from massive gravitational forces?

James said...

Whoops, I didn't mean to post that anonymously.

HoBs said...

yeah, i suppose gravity is the ultimate source well sorta. technically, it's not even a valid question because energy doesn't come from anywhere, being conserved and all. though technically, gravity in the sun, is not geothermal, because geo means earth, so even sun-located gravity power should be called solar.