World energy problems solved?

[Deutherius]

I think that we should call our energy generators "energy harvesters" because that is what we are doing. We don't create energy - remember conservation of energy, we just harvest from the universe and turn it to a usable form.

I've personally never heard the term "energy generator" - most of the time it would be something like "electric generator", which is, albeit maybe unintuitive, technically correct - they do generate electric current from some other source of energy. "Energy harvesting" makes me think of the process of waiting for something to grow, which in this context doesn't seem entirely right. I'd propose the term "energy convertor", as that's exactly what it does - converts energy of one form to some other form.

[StrandedonEarth]

Imagine we do have unlimited access to clean energy. What are we going to do with the residual heat all these sources are going to produce for us?

What we really need is a device that can convert low-grade heat directly into electricity, with little temperature differential. Essentially a thermocouple with one end stuck at a very cold temperature. *brainstorm!* Maybe something like a piezo-crystal that could turn the motions of the atoms (that increase as things heat up) directly into electricity? If an inexpensive-enough device could generate electricity directly from waste heat, or especially from ambient temperature, that should go a long way towards getting us unlimited access to clean energy.

And probably upset a few energy corporations too. And make whoever patents it very rich.

Edited April 10, 2015 by StrandedonEarth

[Leszek]

I don't think anyone fails to understand your point, especially after the third time you exlained it We are just having a little fun with impossible ideas, is all.

I guess I was a bit myopic, I didn't see the response that I expected and didn't consider all that many reasons why that would be. Still I might just go for a fourth if I can find a way to say the same thing slightly differently again.

What we really need is a device that can convert low-grade heat directly into electricity, with little temperature differential. Essentially a thermocouple with one end stuck at a very cold temperature. *brainstorm!* Maybe something like a piezo-crystal that could turn the motions of the atoms (that increase as things heat up) directly into electricity? If an inexpensive-enough device could generate electricity directly from waste heat, or especially from ambient temperature, that should go a long way towards getting us unlimited access to clean energy.

And probably upset a few energy corporations too. And make whoever patents it very rich.

There are some. I can't remember the name so I can't find the youtube video but there is one that all you need to do is leave it out in the sun and it drives a piston. Just from thermal expansion of the air inside.

The problem is, the less temperature differential the less usable heat, the less usable heat the less power available to convert to electricity.

Look what I found while trying to find it though.

Update: found it, a Stiling Engine

Edited April 10, 2015 by Leszek

[Kryten]

What we really need is a device that can convert low-grade heat directly into electricity, with little temperature differential. Essentially a thermocouple with one end stuck at a very cold temperature. *brainstorm!* Maybe something like a piezo-crystal that could turn the motions of the atoms (that increase as things heat up) directly into electricity? If an inexpensive-enough device could generate electricity directly from waste heat, or especially from ambient temperature, that should go a long way towards getting us unlimited access to clean energy.

And probably upset a few energy corporations too. And make whoever patents it very rich.

Nothing can 'produce energy from heat', only extract energy from the movement of heat along a differential.

[Greenfire32]

Nothing can 'produce energy from heat', only extract energy from the movement of heat along a differential.

Isn't heat really just "wasted energy" though? There ought to be way for us to capture that "waste" and re-purpose it for something useful.

We just don't know how yet.

[Kryten]

Ultimately all processes lead to everything being the same temperature; that's the basic principle of thermodynamics. Trying to reverse it is trying to reverse entropy.

[Leszek]

Isn't heat really just "wasted energy" though? There ought to be way for us to capture that "waste" and re-purpose it for something useful.

We just don't know how yet.

Heat is just energy. Not wasted energy, just energy. All the big power stations we have are heat engines. Nuclear pile is a source of heat. Burning coal is a source of heat. We already capture and use that heat to make power.

A car engine is a heat engine, so why the radiator? That energy that goes into the engine block is waste energy as it doesn't power the motor at all. Can we collect that waste energy? Yes, there have been 6 stroke car engines that inject water into the cylinder. The "waste" heat from the previous combustion cycle turns the water into steam and this expands and pushes the piston down for more energy. Also you can put a Stirling engine on the gas engine block and use the "waste" heat there to power a generator. There are ways to do it. And there are costs associated with those ways and more downsides and other downers in general. Nature is such a pain.

[Deutherius]

Ultimately all processes lead to everything being the same temperature; that's the basic principle of thermodynamics. Trying to reverse it is trying to reverse entropy.

That's not to say you cannot reverse entropy locally. You just need to use energy. Which creates even more entropy somewhere else.

Bummer.

[Admac]

What the OP is referring to is actually a proposed method of drawing power for space craft, the theory is if you draw a wire(s) behind you while in the magnetosphere it will draw current, same as the northern lights.

The big drawback being it weighs more than solar panels and produces some drag. I suppose if access to space got cheap enough, it could scale out to commercially useful, if the drag was offset by Ion engines or something.

NASA did some Gemini era tests, and even looked as a modified version to help slow the ISS orbital decay

http://science.nasa.gov/science-news/science-at-nasa/1998/ast15oct98_1/

[impyre]

What we really need is a device that can convert low-grade heat directly into electricity, with little temperature differential. Essentially a thermocouple with one end stuck at a very cold temperature. *brainstorm!* Maybe something like a piezo-crystal that could turn the motions of the atoms (that increase as things heat up) directly into electricity? If an inexpensive-enough device could generate electricity directly from waste heat, or especially from ambient temperature, that should go a long way towards getting us unlimited access to clean energy.

And probably upset a few energy corporations too. And make whoever patents it very rich.

Thermocouples. I have a few designs that use them, but they are so stupidly expensive because it takes so many of them to do anything useful. Far more efficient is the stirling engine mentioned earlier, capture solar energy as thermal energy, run a generator with it directly. Not quite as efficient as solar panels, but way cheaper (you can dump a *lot* of heat into a well designed stirling engine, and it will take it... and the collectors are fairly cheap to build.) The real problem with solar/wind is that if those technologies are ever implemented on a global scale, we'll be changing weather patterns and such (since solar energy and wind basically drive weather systems)... huge damage could result. IMO, the best answer (aside from fusion) is space-based solar energy collection. Taking it from space means we aren't depriving any natural systems of their energy requirements, we just have to be careful to pump excess energy back out to space as radiation to maintain the proper balance for long term sustainability.

- - - Updated - - -

What the OP is referring to is actually a proposed method of drawing power for space craft, the theory is if you draw a wire(s) behind you while in the magnetosphere it will draw current, same as the northern lights.

The big drawback being it weighs more than solar panels and produces some drag. I suppose if access to space got cheap enough, it could scale out to commercially useful, if the drag was offset by Ion engines or something.

NASA did some Gemini era tests, and even looked as a modified version to help slow the ISS orbital decay

http://science.nasa.gov/science-news/science-at-nasa/1998/ast15oct98_1/

The OP wasn't even a complete sentence... how can you be sure that's what he's referring to? It sounded to me like he was suggesting we might use the earth as the driving force of a generator (which seems to be how most people interpreted it).

[Tommygun]

So if all electrical generators are magnets surrounded by wires, and the earth's core is a magnet...

I think an electrodynamic tether is as close as you will get to this:

http://en.wikipedia.org/wiki/Electrodynamic_tether

You would then need to beam the power down by microwaves or lasers.

Even solar and wind generation would be a lot cheaper right now, but maybe sometime in the future.

[sgt_flyer]

I'm wondering what would be the power density of such a system

Because power and storage density is the current problem we have to solve

(Along with conversion efficiency)

Power plants might be big, but it's nowhere near the surface area required by equivalent renewable sources (+ the energy storage needed by such systems)

Regarding conversion efficiency, we mostly currently work from generating heat, and steam with it, then electricity (multiple conversions with efficiency losses between each phase) - and we really should try to find a way for direct conversions. (Heck, nuclear power plants are among the worst at conversion efficiency from heat to electricity - because they need to keep the cores at very low temperatures to prevent fuel rods damage - but the sheer power of the fission reaction is so high that it overcomes this downside - at the cost of needing gigantic cooling systems to evacuate all this waste heat)

[RainDreamer]

Well, we do have ways to convert heat directly to electricity, like thermoelectric generators but....those are extremely inefficient, enough to make it better to just use steam to generate electricity.

Lets hope someone will figure out a way to convert energy to usable forms better.

[sgt_flyer]

Let's skip heat generation in this case like the proposed fission fragment / dusty plasma reactors concepts - which generate few heat, but huge ejection speeds of the reaction fragments - which ends up being an ion beam . (Fission fragment rockets let this beam out in the open to have an extremely efficient engine, reactors basically convert this ion beam speed into electricity (the concepts figures talks about 90%+ efficiency)

[megatiger78]

The OP wasn't even a complete sentence... how can you be sure that's what he's referring to? It sounded to me like he was suggesting we might use the earth as the driving force of a generator (which seems to be how most people interpreted it).

ok, fixed the op.

[arkie87]

Since this is KSP, you could put a wire coil in a satellite in orbit around Kerbi... i mean Earth. In such a way, the coil will orbit the earth and experience a changing magnetic field, and therefore, a current will be created in the wire.

Interestingly enough, the electricity you generate will create an opposing magnetic field which will slow the satellite down, and the satellite will eventually crash. Conservation of energy is a b****.

[vger]

And it doesn't move.... We'd have to build a gigantic ring of wire around Earth to get any power. And then have it spin around Earth at a reasonable pace...

Giving everyone an exercise bike with a dynamo would work better.

Earth's core has its own spin.