World energy problems solved?

[megatiger78]

So if all electrical generators are magnets surrounded by wires, and the earth's core is a magnet, could we put some wires around the earths core and make power?

Edited April 12, 2015 by megatiger78

[RainDreamer]

I think calling electrical generators magnets surrounded by wire is a tad bit oversimplification.

[Deutherius]

It's been a while, but from what I recall from high school, the magnet inside/next to a coil has to move in order to generate any current - how exactly would you propose we exploit the Earth's magnetic field to generate electricity for everyone?

[megatiger78]

It's been a while, but from what I recall from high school, the magnet inside/next to a coil has to move in order to generate any current - how exactly would you propose we exploit the Earth's magnetic field to generate electricity for everyone?

Well.... The earth's core creates a magnetic field anyway...

[Starwhip]

Well.... The earth's core creates a magnetic field anyway...

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.

[Leszek]

The magnets and the coils have to move relative to each other. So you would have to have coils move around the earth. The generation of power will try to slow those coils down so you will need to put energy into moving them. The power you get out of the coils will be less than the energy you need to move them. At that point you might as well have a traditional power station.

The reason why we worry about energy in the first place is because it isn't easy to come up with solutions. Everything we have on the table has drawbacks, fossil fuels pollute and have limited supply, nuclear energy is potentially dangerous, wind and solar are sporadic, fusion is still 20 years off for the 4th decade in a row, etc, etc...

[Superfluous J]

I think calling electrical generators magnets surrounded by wire is a tad bit oversimplification.

The Saturn 5 is just a firework with some extra fuel and maybe some metal.

[Deutherius]

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.

I'm not sure how spinning that ring would work, if even (probably dependent on the axis around which it would rotate). Plus the stuff Leszek described.

And we might also want to use some of that energy... How would we transfer it from the coil to the surface? I'd take the exercise bike any day

[Starwhip]

I'm not sure how spinning that ring would work, if even (probably dependent on the axis around which it would rotate). Plus the stuff Leszek described.

And we might also want to use some of that energy... How would we transfer it from the coil to the surface? I'd take the exercise bike any day

You make it equatorial, then spin it so that it crosses over the poles. And then back to the equator.

If it rotated once every 48 hours it would be going at 500 miles an hour at its furthest point. If it was 96, 250 miles an hour.

That right there is an engineering problem. I'm not even sure that it would generate enough power to sustain anything at that speed. (1 rev every 96 hours, not 250 miles an hour.)

Speaking of which, how the heck would you power the ring itself? Solar panels? Just use the damn things to power civilization directly!

[Kerbart]

That's way too complicated. Just put a little pinwheel on the top of your roof and let it generate all the electricity you need!

Too small, you say? Aaah, now we're getting to the core of the problem with your solution!

Related, you're just going to replace one problem with another. 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?

[RainDreamer]

I think we would sooner build a dyson sphere or the like than something like this.

[cpast]

Moving a coil of wire through a magnetic field requires you to expend more energy moving the wire than you get out of it in electric power. Where would this energy come from? In a normal power plant, you get it by burning some fuel in order to heat water into steam which then uses the heat to spin a turbine; in solar-thermal plants you use solar energy to heat water to the same end; in hydro plants you drop water from a higher altitude to a lower altitude (the water is ultimately placed at the higher altitude by heat from the sun, which causes water to evaporate at which point solar-powered winds move it until it can precipitate at high altitude); in geothermal plants you use the heat within the Earth (some of which comes from compressing dust into a planet via gravity and some of which comes from radioactive decay); etc. Nothing creates energy from scratch; everything that produces energy requires an energy input or a mass input.

[Leszek]

You make it equatorial, then spin it so that it crosses over the poles. And then back to the equator.

If it rotated once every 48 hours it would be going at 500 miles an hour at its furthest point. If it was 96, 250 miles an hour.

That right there is an engineering problem. I'm not even sure that it would generate enough power to sustain anything at that speed. (1 rev every 96 hours, not 250 miles an hour.)

Speaking of which, how the heck would you power the ring itself? Solar panels? Just use the damn things to power civilization directly!

That will not work.

The power generated comes out of the motion of the rings. You generate 500 mega watts of power you take 500 mega watts of kinetic motion from the ring. (Never mind inefficiencies that just make things worse.) If you have enough solar panels in orbit to generate that kind of power to keep the ring going, then you should just forget the ring and beam the solar power directly to earth.

There is no free lunch. Any power generated has to come from somewhere. The ring proposal skips a step. It starts with the power generator, but the power generator doesn't actually create power. It converts kinetic power to electrical power. It is where this kinetic power comes from that is the issue.

Edited April 10, 2015 by Leszek

[RainDreamer]

Makes me wonder if we are to put, say a planetary coil on the same orbit as earth, but on opposite direction, wouldn't that satisfy the moving requirement? Every half year or so(?) the earth will pass through the ring and transfer energy to the coil. We can have massive battery banks there and collect/replace it every pass to return it to earth for use.

How long can we do that before Earth experience significant change to it's orbit?

I know this is all better done with just solar panels and dyson sphere/swarm arrangement, but I like to entertain this idea a little more

[Deutherius]

Makes me wonder if we are to put, say a planetary coil on the same orbit as earth, but on opposite direction, wouldn't that satisfy the moving requirement? Every half year or so(?) the earth will pass through the ring and transfer energy to the coil. We can have massive battery banks there and collect/replace it every pass to return it to earth for use.

How long can we do that before Earth experience significant change to it's orbit?

I know this is all better done with just solar panels and dyson sphere/swarm arrangement, but I like to entertain this idea a little more

I have seen a similar idea somewhere (probably yt comment section, but bear with it for a second) - what if we put a huge magnet into orbit, and then put up "gates" of coils in opposite orbit of the same trajectory? The magnet would pass through them and generate electricity.

The idea is neat, but would crash and burn (figuratively AND literally) pretty quickly. Not to mention all the engineering problems of creating a perfect gate sequence and transferring all the power to the ground.

I'd imagine the huge coil you are describing wouldn't even last an orbit - the gravitational perturbances of all the objects of the solar system would most likely alter its orbit enough to miss the Earth pretty fast.

[PlonioFludrasco]

Didn't the tethered satellite generate electrical power by moving inside Earth's magnetic field?

[Bill Phil]

The field is a bit weak... But that's because of the huge area it takes up.

Let's say we can do it. What are the implications? Would the Earth slow down faster?

- - - Updated - - -

Didn't the tethered satellite generate electrical power by moving inside Earth's magnetic field?

It collected the charged particles... I think. Plus it was spinning around the planet.

[Starwhip]

I have seen a similar idea somewhere (probably yt comment section, but bear with it for a second) - what if we put a huge magnet into orbit, and then put up "gates" of coils in opposite orbit of the same trajectory? The magnet would pass through them and generate electricity.

The idea is neat, but would crash and burn (figuratively AND literally) pretty quickly. Not to mention all the engineering problems of creating a perfect gate sequence and transferring all the power to the ground.

I'd imagine the huge coil you are describing wouldn't even last an orbit - the gravitational perturbances of all the objects of the solar system would most likely alter its orbit enough to miss the Earth pretty fast.

Or smash right into the Earth when it fails to thread the needle.

[Leszek]

Allow me to be more explicit. Power generators are another name for brakes. (Not really but they can and are used this way in some conditions. See regenerative braing.) Like the brakes on your car. The ones that make you stop.

The power output of a generator comes directly from the the kinetic energy that keeps the generator moving. If you take energy out of the system, you have to put that much energy back in to keep the system going.

The coils in orbit will be constantly breaking and trying to stop. Any power you put into getting it moving will be at least (actually more that due to imperfect efficiency.) as much as what was generated. You might as well connect this kinetic energy source directly to a generator on earth and save a bunch of steps and power.

Any question about sources of power MUST ABSOLUTELY start with where this kinetic energy comes from. The coils in the generator are part of the step after the next step. (The next step is the transmission to the generator.)

Edited April 10, 2015 by Leszek

[xcorps]

2 space towers, one at each pole. giant stick connecting them. Faraday disk on the stick. Induction motor with really long wires connected to the disk. Win.

You mad engineers?

[cpast]

Allow me to be more explicit. Power generators are another name for breaks. (Not really but they can and are used this way in some conditions. See regenerative breaking.) Like the breaks on your car. The ones that make you stop.

Railroad locomotives have a brake that literally works like this -- you connect the traction motor to a resistor grid, and bleed off your kinetic energy as heat.

[Leszek]

Railroad locomotives have a brake that literally works like this -- you connect the traction motor to a resistor grid, and bleed off your kinetic energy as heat.

And with that I realized that I was using the wrong spelling for brakes. ROFL. oops. Lemme go fix that...

[Mr_Brain]

Hmm... Assuming you took all the conductive materials from Earth's crust, made coils out of them and put them on the fastest-moving tectonic plate... How much power could you generate using only continental drift and Earth's magnetic field?

[Deutherius]

Allow me to be more explicit. Power generators are another name for brakes. (Not really but they can and are used this way in some conditions. See regenerative braing.) Like the brakes on your car. The ones that make you stop.

The power output of a generator comes directly from the the kinetic energy that keeps the generator moving. If you take energy out of the system, you have to put that much energy back in to keep the system going.

The coils in orbit will be constantly breaking and trying to stop. Any power you put into getting it moving will be at least (actually more that due to imperfect efficiency.) as much as what was generated. You might as well connect this kinetic energy source directly to a generator on earth and save a bunch of steps and power.

Any question about sources of power MUST ABSOLUTELY start with where this kinetic energy comes from. The coils in the generator are part of the step after the next step. (The next step is the transmission to the generator.)

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.

[RainDreamer]

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.

Energy harvesting also means you have to expend energy to get energy from the environment, rather than the nebulous idea that we somehow create energy from something.

And because we have to expend energy to get energy, it is important to make sure that the energy we get is more than the energy we spend. We have to do as little as possible while letting the universe handle the rest.

Like, we don't haul water ourselves and pour it into a hydroelectric "harvester" , we let the water cycle do that for us. We only "harvest" the energy from the movement of the water. We expend energy only to build the harvester.