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# Lightning as an energy source?

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Would it be possible to harness the energy from a lightning strike? I guess if we could, fossil fuel would become obsolete. Couldn't cosmic rays, aurora, tornado's and hurricanes also theoretically be used as a source of energy?

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Ive done quite a bit of study on this, and no, it wouldnt end the fuel problems.

at it best it would help out by less than 1%.

1) you need to rip the amount of Ground strikes from the actual majority of lightning that never reaches ground, that cuts that Number right down.

2) you have to factor in coverage (you will never be able to "catch" all of them, very few in fact), that again cuts that number right down.

it does continue, and the picture at the end of it isnt great

one of the main factors is the charge curve of a capacitor, and with such a brief time a strike occurs in, you dont end up with much.

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As to actually implementing your ideas. You may want to check out the DIY 1000 watt wind turbine project. You will not be able to harvest the complete energy output of tornadoes and hurricanes, but you can at least get something out of it.

Edit- somebody said:

Tornadoes and hurricanes are way too destructive to harness any energy from them.

And I disagree. You cannot harvest the totality of energy, but the increased wind speed can be harvested to some extent, etc.

Re: cosmic rays. That's an interesting question. Gamma radiation is said to release more energy than other photons, so how big of a surface would we need if we wanted to harvest the power of gamma rays and get some stable energy levels? Would it have to be the size of the area of a city? Or maybe the size of our planet? Would we want to point the surface perpendicular to any particular area of the universe, to maximize the likelihood of hitting gamma photons?

- Bryan

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Re: cosmic rays. That's an interesting question. Gamma radiation is said to release more energy than other photons, so how big of a surface would we need if we wanted to harvest the power of gamma rays and get some stable energy levels? Would it have to be the size of the area of a city? Or maybe the size of our planet? Would we want to point the surface perpendicular to any particular area of the universe, to maximize the likelihood of hitting gamma photons?

- Bryan

There are far far far more visible spectrum photons hitting is so they should be our primary target.

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So I did some calculations of how large a detector would have to be if we wanted to capture the gamma photons at 10^11 eV (10^-8 joules). So if we wanted to capture 80 terajoules of energy, enough for an atomic explosion, by my calculations we would need much more than a trillion octillion square light years (about 10^88 square light years?) of our absorbent machine/substance.

Note that the observed universe is only 10^9 light years across. Thank you, Mr. Dyson.

- Bryan

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Would it be possible to harness the energy from a lightning strike? I guess if we could, fossil fuel would become obsolete. Couldn't cosmic rays, aurora, tornado's and hurricanes also theoretically be used as a source of energy?

Using lighting as an energy source would be very impractical because it hardly strikes at the same point, and you can only get a fraction of its total energy. You would have to build a huge number of towers to capture it. Not only that, they only occur in short flashes, so it is not enough to meet the power demands of a single household, never mind an entire town or city.

There are rockets to help create and direct lighting strikes, but these aren't as energetic as the ones that discharge naturally.

Here is more info: http://plaza.ufl.edu/rakov/FAQ.html

-----------------------------------------------

There aren't a lot of cosmic rays that strike the earth, and the strongest ones that hit Earth don't deliver nearly enough energy to power a lightbulb. And solar wind doesn't really have a lot of momentum; it has far less momentum than a human breath.

It's better just to use solar radiation from the sun, preferably with satellites in space that could be beamed down into the Earth.

Tornadoes and hurricanes are way too destructive to harness any energy from them, plus a hurricane acts over a very large area.

Note that the observed universe is only 10^9 light years across. Thank you, Mr. Dyson.

- Bryan

The observed universe is a little bit bigger than that, about 1.3 X 10^10 lightyears .

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So I did some calculations of how large a detector would have to be if we wanted to capture the gamma photons at 10^11 eV (10^-8 joules). So if we wanted to capture 80 terajoules of energy, enough for an atomic explosion, by my calculations we would need much more than a trillion octillion square light years (about 10^88 square light years?) of our absorbent machine/substance.

Note that the observed universe is only 10^9 light years across. Thank you, Mr. Dyson.

- Bryan

How did you get to this number? What is the flux density on the surface of the earth?

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How did you get to this number? What is the flux density on the surface of the earth?

Was not the flux density on the surface density of the earth, mind you. I was using this SVG image over at Wikipedia on cosmic ray flux versus particle energy and a conversation with a friendly particle physicist earlier this morning.

- Bryan

Edit:

The observed universe is a little bit bigger than that, about 1.3 X 10^10 lightyears .

Haha, so I was off by an order of magnitude. How much volume did I neglect? Probably enough for trillions of trillions of earths.

I see,

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I think what also needs to be realised is that, although it is Said that a single bolt of lightning has enough energy light up a small town for a year (or words to that effect).

Most of that energy is Gone along the Path of the strike, it means the ENTIRE energy output of the whole thing. incl the Light and heat given off and the EMP created, not a single point contact

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As to actually implementing your ideas. You may want to check out the DIY 1000 watt wind turbine project. You will not be able to harvest the complete energy output of tornadoes and hurricanes, but you can at least get something out of it.

Edit- somebody said:

And I disagree. You cannot harvest the totality of energy, but the increased wind speed can be harvested to some extent, etc.

Re: cosmic rays. That's an interesting question. Gamma radiation is said to release more energy than other photons, so how big of a surface would we need if we wanted to harvest the power of gamma rays and get some stable energy levels? Would it have to be the size of the area of a city? Or maybe the size of our planet? Would we want to point the surface perpendicular to any particular area of the universe, to maximize the likelihood of hitting gamma photons?

- Bryan

Now you just have to wait for a hurricane to hit where you have your wind turbine, or cart it into the path of the storm and wire it up, hoping that the storm doesn't wipe out all of your efforts. How much of a return do you expect on this?

One additional problem with gammas is that they are penetrating radiation. You need a thick detector if you hope to recover a reasonable fraction of the energy.

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Wasn't Tesla trying to do something slong the same lines? I believe he was trying to harness the static electricity from the atmosphere instead of direct lightning strikes though, but it seems similar.

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• 2 weeks later...
Ive done quite a bit of study on this, and no, it wouldnt end the fuel problems.

at it best it would help out by less than 1%.

1) you need to rip the amount of Ground strikes from the actual majority of lightning that never reaches ground, that cuts that Number right down.

2) you have to factor in coverage (you will never be able to "catch" all of them, very few in fact), that again cuts that number right down.

it does continue, and the picture at the end of it isnt great

one of the main factors is the charge curve of a capacitor, and with such a brief time a strike occurs in, you dont end up with much.

Hmm? What if we were to assign a specific area (let's say some place that gets lightning frequently) and have some large supported interconnected network of uninsulated wires of some conductor like copper or aluminum, and have it arranged sort of like a grid (well except 3-D of course) that goes high into the sky but the angle can be changed so that the network can be passed through a charged cloud, and have it so that all the metal converges somewhere closer to the ground to combine all the electricity it gathers from the charged cloud, and give that electricity a path to the ground such that in order to reach the ground it has to pass through whatever means are used to harness the electricity?

I was thinking about this, and I think that'd be a good way to attract the lightning, and even take some lightning strikes that might otherwise be cloud-to-cloud strikes and make them cloud-to-ground instead. As for whatever means, I was thinking maybe running it through water with an electrolyte in it(well, if the electrical transformer concept was applied so as to step-down the voltage to step-up the current) so as to apply water electrolysis to store the energy, or if that wouldn't work maybe running it through a sheet of some kind of filament, (like the kind used in toasters) then immerse the heated filament in water and use a steam turbine to generate electricity, and then run THAT electricity through water to store the energy?

Also, what about lightning electromagnets? As in, if the converged conductor from my wire network idea was coiled around a ferromagnetic material to create a solenoid, wouldn't the sheer strength, even if only for a short period of time, of the magnetic field created, have all sorts of potential applications?

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A typical bolt is (from wiki) about 500MJ. On average it hits about 100 times a second. That's quite a bit of power- 50 GW or so. The world uses about 3600 GW of electricity at the moment. (from this site http://www.cslforum.org/japan.htm)

Lightning isn't going to solve our problems. If it was easy to harvest then it could make some small contribution but it's a non starter really.

Pity.

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A typical bolt is (from wiki) about 500MJ. On average it hits about 100 times a second. That's quite a bit of power- 50 GW or so. The world uses about 3600 GW of electricity at the moment. (from this site http://www.cslforum.org/japan.htm)

Lightning isn't going to solve our problems. If it was easy to harvest then it could make some small contribution but it's a non starter really.

Pity.

That's 50 GW, for 1 second, but it's not necessarily sustained for very long. Peak power and average power aren't the same thing. The 3600 GW from your link (241.3 GW/0.067) is production capacity, not use, and production capacity is higher as it has to account for peaks. Using the electricity consumption numbers I get about 1800 GW as the average electrical consumption rate: 106GW-hr/(8760hr * 0.064).

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No, there are roughly 100 strikes a second across the whole earth so it's an average power. It is sustained practically indefinitely. (Did you think lightning strikes lasted a whole second?)

If the used power is only half the installed power it hardly matters. Ther's still no point looking at lightning to solve the energy crisis.

(I should probably add that those figures are a few years out of date.)

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No, there are roughly 100 strikes a second across the whole earth so it's an average power. It is sustained practically indefinitely. (Did you think lightning strikes lasted a whole second?)

If the used power is only half the installed power it hardly matters. Ther's still no point looking at lightning to solve the energy crisis.

(I should probably add that those figures are a few years out of date.)

OK, I thought you were talking about one region where you had the infrastructure set up to recover the energy, and it didn't seem right.

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OK, I thought you were talking about one region where you had the infrastructure set up to recover the energy, and it didn't seem right.

Actually I think that's what I was talking about, maybe you mixed up JC's reply with mine.

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• 11 months later...

What about lightning rods? There is one on the CN tower in Toronto that gets struck AT LEAST 40 times a year.

What is the problem with routing this electricity into a capacitor or battery?

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making the capacitor or battery charge fast enough without breaking is the problem I think.

As well as the energy required to manfacture them, would it really be worth it for 40 strikes a year? I doubt it.

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40 strikes a year, be optimistic and call it 1GigaJoule a strike, 40GJ a year = 109.5 MJ a day = 1.27kW

and thats probably taking in all lightning over a fair radius around the tower.

according to wikipedia the average is half that. and not all conductors will be struck 40 times a year.

probably works out to maybe about a milliwatt per square meter. hardly worth collecting unless the price of electricity skyrockets a fair bit.

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• 2 months later...

Regarding the capture of tornadic wind energy...

You can apply the lightning bolt argument here: Lightning AND tornadoes are relatively rare to specific locations. Even in Tornado Alley the odds of a tornado finally coming close enough to a wind farm is remote. Also, technology prohibits this idea from becoming a viable reality for two reasons off the top of my head:

1. Wind turbines large enough to be able to produce higher amounts of energy are just too big to relocate into the (near) path of incoming tornadoes.

and

2. Wind turbines are only physically capable of producing electricity from a definate range of wind speeds, generally somewhere above a slight breeze and somewhere below gale force winds.

Building wind turbines to capture the small amount of wind energy in a short-lived and rarely occurring tornado vs. the vast amounts of available energy from long-term weather conditions of windy locales?? It doesn't jive, man.

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I believe the main problem with tornado, hurricane and lightning power is that it is much less constant than the already non-constant wind and sun.

With the investments you do to capture the energy, you need to design your equipment such that it will not break during operation... so it needs to be designed for 500 km/h winds (or something like that), and for massive currents.

So you end up with a huge structure that is virtually unbreakable, but that is not producing 99% of the time.

Therefore, I think you should first think of a way to physically move the generator to the storms where the high winds or lightning occurs. Then you can start to think about the device itself after that. Moving the thing around into storms is (I think) going to be the biggest improvement in efficiency.

The most obvious would be to build a large ship - at least there is enough space on it to build a large structure. But I'm not sure those are fast enough to catch up with storms. And I am not sure you could make it strong enough to survive.

But the problem with sustainable energy is not that we don't have enough of it on earth. There is more than enough wind and sun. We just don't invest enough in it. And any tornado or lightning power is going to face that same problem.

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Any chance one could make the lightning colector verry tall?

Like sandy heath, a most implausable looking building.

http://tx.mb21.co.uk/gallery/sandy_heath-mf-01.jpg

Some buildings do extend into the clouds. Maybe a table shaped stucture with 4 legs and a grid of metal between them? Or starting high the mountains or in a thunderstorm rich area to start with?

I know storing the power is really hard. Maybe you could use it emidatly to do something such as jumping a large amount of gaps or lighting a large LED to create the optimun amount of light and then store the energy from that?

Lightning also creates powerfull yet low freqency EM waves.

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To catch the lightning, a large structure might be a bit of an overkill.

I've seen researchers who shot fireworks (rockets) into the clouds, and the lightning then chose the exact path of the rocket to strike the earth. I believe that the relatively high concentration of particles (some of which might be ionic, shortly after the launch) is more conducting than normal air.

Alternatively you can attach a thin conducting wire to the rocket.

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