Where does renewable energy come from?

For years there has been considerable pressure from the green movement towards taking advantage of so called renewable energy sources. These include solar, wind, wave and geothermal power and some other ideas, as opposed to fossil fuels or nuclear power, which are based on finite resources. However, the actual source of the renewable energy is neglected in virtually all 0f such discussions. Is it energy “out of thin air?” No, it is not.

In essence, taking advantage of any of these renewable energy sources is about capturing the existing energy that is all around us the nature. Take wind power for example, it is basically transforming the kinetic energy of the winds into electricity. Similarly, wave power means capturing the kinetic energy of the waves and transform it into electricity. Geothermal power is drawing thermal energy (warmth) from the ground, usually to warm households etc. And finally, solar power is capturing the light and warmth of sun that would otherwise go to ground and/or structures. You get the idea.

Common to all of these methods is that energy is taken from one place and put somewhere else, with different efficiency ratios. Important thing to note is that the energy indeed has to come from somewhere, it’s not a by-product of these forces. Implications of this can be rather significant.

For instance, what happens if we draw all the energy we need from the winds around the globe? The kinetic energy of the winds will decrease by the exact same amount that we transform into electricity. Winds have many important functions, like transferring warmth around the world, bringing clouds to rain over dry areas, and so on. The question is, has anyone calculated what are the consequences to the climate if we reduce the power of the winds that much? And how much wind power can we safely use not to do any harm to existing natural forces? Or our power needs just miniscule in comparison to what huge amounts of energy are in the global winds?

Another factor is the way we use the electricity we generate. Practically every usage of electricity wastes some of the energy as thermal energy due to resistance in our current conductors. If the system that distributes warmth around the world more evenly (ie. the winds and/or the waves in oceans) is impaired, what will happen to the warmth we get from our light bulbs, heaters, computers, television sets and other electric items? Will some (urban) places become warmer and other places colder?

And to answer the question where does these renewable energy sources draw their power: the sun. Perhaps with the exception of tidal waves caused by the gravity of the moon, all the other sources owe their existence to the sun. There would be no winds if it weren’t for the uneven distribution of warmth in the first place, neither would there be any currents in the oceans. So, if we didn’t have the sun “up there,” our only energy sources would be fossil fuels and nuclear power.

In an indirect way, oil and natural gas are a form of stored solar energy from millions of years ago. They were formed over long time periods from the remnants of dead plants and animals under high pressure deep in the ground. Those plants and animals owed their existence to the same natural forces we experience today, and the sun. So, what’s left now, if the sun wasn’t around in the first place (but somehow we were)? Coal and uranium.

Coal is unclean. I think we all agree we want to stop burning coal. In addition to greenhouse gases, it produces other health risks which at least in the short-term are even more severe. The ash from coal furnaces is more radioactive than plain uranium. Burning coal produces tiny impurities in the air that cause lung cancer and other respiratory diseases. Etc.

Finally, there’s uranium and nuclear power. Drawing power from nuclear fission isn’t energy from nowhere either. The uranium is fissile and it would slowly release all the energy it has if left to its own devices in the ground. Causing the chain reaction in enriched uranium within nuclear reactors is just making that process faster. It’s also rather inefficient: the so called nuclear waste could be re-enriched and reused as nuclear fuel many times over, and this will also happen in the large scale as the uranium supplies in the ground grow thinner.

Nuclear fusion could be a solution, if ever achieved. It “burns” hydrogen, and there’s hydrogen practically everywhere. Not an infinite source either, but almost. And then there’s that crazy idea of capturing solar energy in the orbit and beaming it down to Earth as microwaves. That would be actually bringing more energy in to this nearly closed system called Earth.

If I had a point when I started writing this article, I lost it somewhere. Sorry. I’ll stop while I can.

Update an hour later: Okay, yes, the thinking above might be a “bit” flawed. Yet I maintain that the influence of getting all energy from renewable sources should be investigated thoroughly.

3 thoughts on “Where does renewable energy come from?”

  1. You have some good points, but I resent the rhetoric, paraphrasing: “greens want us to do renewavble sources, but they don’t tell us where the energy comes from”. We greens do know that, and we talk about it when the subject comes up. As usual, these things are misreported or omitted entirely in news reporting. If you want accurate stories, go to the source (which is nowadays often feasible, thanks to the Internet).

    Ultimately, both fossil fuel and the renewable sources draw their power from the sun. The difference is that with fossil fuel we are essentially burning up “reserve stores”, stuff that we cannot replace at the rate we use them. Renewable sources allow us to feed from the “income”, instead of the capital.

    Ultimately, the best long-term solution would be direct sun-power-to-electricity conversion, but the technology is too immature at this point in time. Also, harnessed fusion would also qualify.

    The main reason fission does not qualify is that not only are we again eating the reserves, we are also creating a lot of toxic waste. Ideally, the waste we produce should be recycled, which cannot be done to fission remains(or is it just not commonly done?).

    As to the effects on winds etc: whatever means we use to create energy, we are changing the heat distribution anyway by creating hot spots where we use energy. I’d guesstimate that generating enough energy from wind to seriously affect winds would take so much windimills that it isn’t practical. (Of course, that probably means that the same applies to getting enough energy from it to feed the entire planetary energy consumption – but nobody suggested to use only winds.)

    Ultimately, the problem is that the planet is overpopulated and the populating is growing. The planet cannot sustain that. Hence, we need to get a grip on that problem, which in turn means solving the world’s poverty issues (poverty induces excessive breeding), or developing a viable space colonialization program. And we all know how likely the latter is…

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