Can We Harvest Lightning for Energy?

[tehno]

Just a wild guess:Do 1000 A steady state arc with 1000 V/m voltage drop seem acceptable?
Than 4 to 5 km long lightning path should require at least 4 to 5 MV.

 

[Ivan Seeking]

I don't know; and I don't know if this could even be calculated.

I once built a system that used 20KV [maybe it was 50KV?] to establish an ionized path, then this path was used to conduct a large current [several thousand amps] at 1KV, but we never did see what the minimum required potential was to keep the path ionized. The thing is, an established ionized path is nearly as good as a wire.

But you do see that as the best case equivalent of ~five gallons of diesel per event, it is hardly worth trying to catch lighting for power, right?

 

[tehno]

But you do see that as the best case equivalent of ~five gallons of diesel per event, it is hardly worth trying to catch lighting for power, right?

Yes,not worth a try .
Fair weather electrical power of 720 MW is equivavalent to the capability of a pretty decent electric power plant.
Unfortunately, this energy is ,as you indicate ,spread all over the globe and impossible to tap I think.
On the other hand,the electrical energy of a single continental storm (which is a local event) exceeds 1 GW!That's what I have read.
Also,I don't have idea how to extract that power from the cloud cell.
And ,at last ,the power of wind of such storm exceeds many times electrical power of it and is much easier to tap.
And again nobody tries to do capture it becouse storms can not be directed and controled.
People are using the wind of fair weather,and solar energy.That's what has been done.

 

[krazyboi]

what happens when there's a lighting storm over the oceans? do a whole bunch of fish go belly up? and are they well done?

 

[taylaron]

im no expert but wouldent the energy in the lightning just travel straight down and out because water is a conductor. since the ground is -ground-
its reached where its trying to reach basically.
right??
if it did do something to a fish, (however) the fish probably would not exist any more.

 

[miggidy]

What about instead of building a structure to dissipate static electricity, to instead run a weather balloon (or blimp) with a long line attached to the ground. Could that perhaps serve as a cheaper alternative to capturing the static in the clouds?

From an electrical engineering perspective, the hardest part about capturing the energy in a lightning strike is indeed its very swiftness. You're probably aware that batteries must be charged very slowly; all batteries have some unavoidable series resistance, and trying to pump tens of thousands of amperes of current through even a tiny resistance will still generate an enormous amount of heat -- enough to essentially fry the battery.

If you really wanted to capture the energy in lightning, you wouldn't want wait until a bolt occurs -- that's just too much current in too short a period of time. Instead, you could conceivably build a tall vertical structure which is capable of continually neutralizing static charge between cloud and ground. This structure could move the same amount of charge as in a lightning bolt, but spread over a much longer period of time. A current of tens of hundreds of amperes is quite easy to deal with, and could be used to charge ultracapacitors, spin up flywheels, etc.

Building such a tower would be an engineering feat, however, and it's not clear to me (I'd need to do some calculations) that the economic value of the energy that could reasonably be captured this way would justify the cost of the structures.

- Warren

 

[taylaron]

im concerned that the amount of surface area a single wire exposed to the air is not nearly enough to capture a reasonable amount of electricity. to my understanding, you need a significant amount of surface area. by then, you've made a serious kite.
-that doesn't keep lightning from striking your blimpthough; unless you like fried blimp on a string 5,000ft above your head.
*good thought.

perhaps the same idea with a wire going to space (able to support its own weight) with a weight on the far end; so you would have a wire being supported by centrifugal force going through the atmosphere.
-then attach heavy-duty streamers miles long in the cloudy region to increase surface area to gather static charge. -still a kite though...

 

[lareth]

This is from a person with no experience at all, buyt I was thinking about this, and I could't sleep thinking about it. here's what my tired brain came up with;

If it was absolutely necessary to harvest lightning, or the electricity currents creating lighting, without thinking of the profit from it at first, how would it be if you divided the source of energy until the amps went down so much it could give out a little bit of charge to a single small capacitor or battery.

Lets say one has a huge metal rod, wide and thick, of some material which wouldn't fry easily. Then divide that by 2, and so on and so on until we'd have a thousand, or 100 000 (I don't know, I'm just making up numbers here) small batteries, with fast filling cababilities.

How would that work? Would it make any difference?

Or having a rod like that to harness the energy in multiple ways until the current would fall below enough to use in what we have now, and could be used instantaniously to light up towns or what not?

It would need something to ease the spikes of current in healthy ways, which do probably exist, but I no nothing about that. Think of all the bulbs popping when a lightning would hit the harvester..

 

[3.14pi]

This is a very good idea although will it be worth the money?

 

[Mech_Engineer]

1.21 jigawatts?!

[PLAIN]http://pneumaticaddict.files.wordpress.com/2008/12/doc_brown-full-1.jpg

 

[taylaron]

This is from a person with no experience at all, buyt I was thinking about this, and I could't sleep thinking about it. here's what my tired brain came up with;

If it was absolutely necessary to harvest lightning, or the electricity currents creating lighting, without thinking of the profit from it at first, how would it be if you divided the source of energy until the amps went down so much it could give out a little bit of charge to a single small capacitor or battery.

Lets say one has a huge metal rod, wide and thick, of some material which wouldn't fry easily. Then divide that by 2, and so on and so on until we'd have a thousand, or 100 000 (I don't know, I'm just making up numbers here) small batteries, with fast filling cababilities.

How would that work? Would it make any difference?

Or having a rod like that to harness the energy in multiple ways until the current would fall below enough to use in what we have now, and could be used instantaniously to light up towns or what not?

It would need something to ease the spikes of current in healthy ways, which do probably exist, but I no nothing about that. Think of all the bulbs popping when a lightning would hit the harvester..

Your Idea is certainly an option, although there are several impracticalities facing development. First of all, an average lightning strike is about 10,000 - 20,000 amps and lasts perhaps 20 milliseconds according to Mark Stenhoff.

Although tying a lightning rod into a parallel circuit with say, 100,000 500mAh capacitors on each end lead is a bit impractical the greatest barrier is the avalible charging time. The capacitors used would need to be able to charge in ~20 milliseconds and hold half a coulomb of electricity.

Well! I guess you need to stick one of these suckers somewhere there is a LOT of lightning! The lightning rod would need to be immense to get the frequency of strikes needed for a reasonable profit. Investors would want to see a near immediate profit from their money, not perhaps 5-10 charging cycles a year... Compare that to the cost of electricity and simply charging them at home. But of course, if you want to be green and use this method, the capacitors need to be used/ discharged very quickly or the charge will dissipate. Time time time!

-Tay