Isn't wind and hydro energy just secondary solar energy?

Well I put a Solar Panel in the bathtub, H'mmmm no power output....
I also stuck it in the wind, H'mmmm no power output..!!!!!

I guess that would be a NO !!!!!

 

Actually, solar energy is just secondary NUCLEAR energy, so wind, hydro, PV, most geothermal, and nearly everything but tidal energy is fundamentally nuclear.

Richard

 

Semantics,,

It is all solar power,,, the key is whether or not it is sustainable/clean etc. PV Solar,, has some environmental costs,, Hydro,, in many cases has massive environmental costs. Wind,, some environmental cost. Nothing is free except conservation!

The question should be, is what I propose to do as an alternative BETTER than what I am replacing. Not an easy question.

Icarus

 

Without the sun there wouldn't be any oil so it could be argued that oil is solar energy

 

This is the correct answer.

The only energy not from nuclear is that left over from the Big Bang, and that is pretty ambiguous since *everything* came from the Big Bang.

Solar energy comes from nuclear fusion. Nuclear fission comes from heavy elements created from exploding stars. It's all about stars.

Tom

 

Don't forget Chemical Energy.

 

All of those chemicals were created by nuclear reactions. Higher chemical energy levels were obtained only through the application of external energy, which came from nuclear. You can't get away from it.

Tom

 

Well, not quite. However, without the sun's gravity well, the planet earth would not have formed. And gravitational push/pull has some affect on warming the interior of solar bodies. I am not sure how much of the earth's interior warmth is renewed by gravitational stresses.

While geothermal isn't 100% renewable, it is many magnitudes greater than all fossil fuels used so far and that still exists in the ground.

 

Geothermal energy comes mostly from nuclear fission, while some is from tidal effects and left over heat from formation. Ultimately that means it all comes from stars. The tidal effects are from our sun, but the fission is from previous stars.

No energy is 100% renewable. We are all part of a cosmic pinball bouncing toward the bottom of the game. Thermodynamics tells us that we will eventually come to a stop at the bottom, unless the Big Bang is cyclical and acts like a giant flipper, knocking everything back into play.

Tom

 

Tidal energy is from the pull of the moon, which is gravitational, not nuclear.

 

You beat me to it. I agree that geothermal energy is lunar energy. The moon produces tidal forces within the earth's crust that are considerable. It would be interesting to know if the earth's iron core would have cooled by now if it weren't for the tidal forces of the moon.

 

The moon is moving because of nuclear energy. It was tossed out by an exploding star. You can't get away from it without invoking the energy released by the Big Bang, whatever that was.

Tom

 

One 'out there' idea I came across that is fun to ponder, is that the accepted explanation of the core's heat wouldn't have kept the core hot for so long. So, perhaps there is a micro-blackhole at the center of the planet heating the place up with hawkian radition.

 

The latest theory on the creation of the moon is that in the early days of the creation of our planet (when it was still rather active) it was side-swiped by a honkin' big body (could it have been the planet between Mars and Jupiter that is now the astroid belt?). The earth was blown apart, and re-formed with the moon forming in orbit around it (see Theory 5 in this link: Theories of Formation for the Moon).

Yes, eventually everything is fussion, but other forces are in play between the times matter is inside a star (and eventually all matter winds up in a star or being ejected from a star, except possibly that which is trapped in a black hole).

 

I believe by now it would have devoured the matter in the planet. Or would it have evaporated?

In Hawking's "recanting" of his original statement that nothing escapes a black hole (the Hawking Radiation you refer to) he postulated some formulas to calculate input and output values. This was interesting in that it showed that a micro black hole would "evaporate" rather quickly (even on a cosmic scale it was quick - in the nanoseconds range) if it wasn't being constantly fed matter (or had started from a large enough mass that the input exceeded the loss of mass in Hawking radiation, such as a collapsing star).

A few weeks after reading this, I read that one of the supercolliders had created "something" that was short lived but exhibited characteristics of a black hole. I ran their mass estimates of the particle, and the time it existed through Hawking's formula and, low and behold, it was within an order of magnitude of all matching up. Could they have created a micro black hole, and could this have proven Hawkings latest theories? I believe so, but "damn it Jim, I'm a Management Scientist not a Doctor of Particle Physics!" I passed the info on to others but have seen no papers surface on the subject. I'd write my own but the scientific community won't listen to someone without the "proper" degree...

In any case, if Hawking is right (his math sure looks right) then this really kills some cool sci fi plot lines that have been used a lot - micro black holes powering our Prius in 2050, for one!

 

Tides are caused by the moon, not momentum (besides, even a pendulum requires energy input in the form of a weight or spring). And, yes, tides could provide a lot of energy, but they're hard to harness at any scale.