Getting usable energy from lightning for powering things

Thread Starter

-live wire-

Joined Dec 22, 2017
959
According to a very reliable source (Wikipedia), a lightning discharge is typically around a gigavolt and 30-400kA, for 10s of uS. Preceding that, there is 100s of mS of establishing an ion channel. There are 100s of amps there. If my very reliable source is completely wrong, please let me know. But regardless, it is still a HUGE amount of power, even when you account for time and Wikepedia.

So shouldn't there be some way to convert this energy into stored energy and then use it to power a city or whatever? I know that you would need 50 feet of teflon to insulate a gigavolt, but even with these challenges wouldn't there be some way? Is there any research on the subject or promising ideas, or is it just too impractical with such high voltages? And even if this is not possible, would it be possible to make a high voltage capacitor or something to do lightning tests later or for other scientific purposes where extremely high voltage is needed?

Live Wire
 

nsaspook

Joined Aug 27, 2009
13,079
Not really, lightning discharges are a static electricity event not the current electricity we normally use so conversion is a big problem (engineering not physics) but maybe you can ask these guys.
https://nypost.com/2018/05/10/duo-wearing-tin-foil-spacesuits-busted-in-nasa-scam/
A father-and-son duo from India conned a businessman — by wearing fake spacesuits made out of tinfoil — telling him they had a deal with NASA and sold rare space equipment that could generate electricity from thunderbolts, according to reports.
 

Thread Starter

-live wire-

Joined Dec 22, 2017
959
Not really, lightning discharges are a static electricity event not the current electricity we normally use so conversion is a big problem (engineering not physics) but maybe you can ask these guys.
https://nypost.com/2018/05/10/duo-wearing-tin-foil-spacesuits-busted-in-nasa-scam/
lol. I am asking about how you might convert it into lower voltages and store it, and if it might make any sense, now or in the future. I know it is possible with infinite resources.
 

nsaspook

Joined Aug 27, 2009
13,079
I would think the most physics practical (unlikely to be economically practical) way is to convert the strike to heat (thermal energy) in some fashion and then use that heat to generate current electricity. Direct electrical conversion seems to be totally impractical now or in the future.
 

Thread Starter

-live wire-

Joined Dec 22, 2017
959
I would think the most physics practical (unlikely to be economically practical) way is to convert the strike to heat (thermal energy) in some fashion and then use that heat to generate current electricity. Direct electrical conversion seems to be totally impractical now or in the future.
Ok.
 

xox

Joined Sep 8, 2017
838
Not really, lightning discharges are a static electricity event not the current electricity we normally use so conversion is a big problem (engineering not physics)
True but considering the rapid advances material sciences, who knows? Vanadium dioxide for example. Connect a thick cable of that stuff to a huge capacitor bank and theoretically you could get a fairly efficient transfer of energy.

According to a very reliable source (Wikipedia), a lightning discharge is typically around a gigavolt and 30-400kA, for 10s of uS. Preceding that, there is 100s of mS of establishing an ion channel. There are 100s of amps there. If my very reliable source is completely wrong, please let me know. But regardless, it is still a HUGE amount of power, even when you account for time and Wikepedia.

So shouldn't there be some way to convert this energy into stored energy and then use it to power a city or whatever? I know that you would need 50 feet of teflon to insulate a gigavolt, but even with these challenges wouldn't there be some way? Is there any research on the subject or promising ideas, or is it just too impractical with such high voltages? And even if this is not possible, would it be possible to make a high voltage capacitor or something to do lightning tests later or for other scientific purposes where extremely high voltage is needed?

Live Wire
Even if there were a practical method to capture and store that energy, the net yield would likely be too low to justify the cost of the infrastructure. Spend $50,000 on a lightning-harvester and then wait years for a single bolt to strike the mast on your roof. Power your home your home for maybe a day or two and you just saved yourself something like $50 max, right?
 

Wendy

Joined Mar 24, 2008
23,415
To my mind it would be like harnessing the wind power of a tornado or hurricane. Plenty of energy there but predictability is the real problem. They don't stay put that long.
 

Thread Starter

-live wire-

Joined Dec 22, 2017
959
To my mind it would be like harnessing the wind power of a tornado or hurricane. Plenty of energy there but predictability is the real problem. They don't stay put that long.
There are some regions with many more strikes than others, though. In addition to that, you could probably have lightning rods directed to it instead of it being purely random.

True but considering the rapid advances material sciences, who knows? Vanadium dioxide for example. Connect a thick cable of that stuff to a huge capacitor bank and theoretically you could get a fairly efficient transfer of energy.



Even if there were a practical method to capture and store that energy, the net yield would likely be too low to justify the cost of the infrastructure. Spend $50,000 on a lightning-harvester and then wait years for a single bolt to strike the mast on your roof. Power your home your home for maybe a day or two and you just saved yourself something like $50 max, right?
Maybe solely as a means of producing energy, it is a waste of money. But 100s of megavolts and even a few gigavolts pulsed on demand could be incredibly useful for many things. I am sure there would be countless scientific uses. And as you mentioned, material science has been advancing rapidly and certain things have become much more viable.
 

nsaspook

Joined Aug 27, 2009
13,079
True but considering the rapid advances material sciences, who knows? Vanadium dioxide for example. Connect a thick cable of that stuff to a huge capacitor bank and theoretically you could get a fairly efficient transfer of energy.
It might make a good thermal converter as the current passes through the cable to the heating element but what capacitor dielectric will stand up to a billion volt potential bolt that jumped miles across space with microsecond Δi/Δt rise times? You don't have a simple DC or AC current to store because of the initial (negative or positive downward or upward flashes) peak and ground return stroke after the feeler contacts the terminal from the electrostatic discharge. This can generate a 15kV+/M electric pulse field with a just as powerful magnetic pulse field from the 20+kA current at least a hundred feet from the discharge terminal. IMO it would be very hard to get anything close to efficient transfer of energy using electrical energy storage by charge separation.
 

MrChips

Joined Oct 2, 2009
30,706
I think that you are forgetting something. Lightning strikes don't just happen suddenly out of the blue. It takes time for the charge separation to buildup until the air ionizes and then the breakdown takes place. This is exactly how a Van der Graaf generator works.
Hence you do not have to wait for a lightning strike. What you need to do is harness the energy during charge separation much like in charging up a super capacitor.
 

nsaspook

Joined Aug 27, 2009
13,079
I think that you are forgetting something. Lightning strikes don't just happen suddenly out of the blue. It takes time for the charge separation to buildup until the air ionizes and then the breakdown takes place. This is exactly how a Van der Graaf generator works.
Hence you do not have to wait for a lightning strike. What you need to do is harness the energy during charge separation much like in charging up a super capacitor.
Hydroelectric dams, solar panel and thermal collection facilities are a much more efficient ways to harness energy from the sun instead of a ¼ of a kilowatt-hour of power (worth about a nickel) per possible discharge or tap from cloud charge separation.
 

Wendy

Joined Mar 24, 2008
23,415
The are getting good energy from geothermal in Hawaii but the plant is being threatened by being buried in lava, illustrating the problems with powerful things nicely.
 

Thread Starter

-live wire-

Joined Dec 22, 2017
959
Hydroelectric dams, solar panel and thermal collection facilities are a much more efficient ways to harness energy from the sun instead of a ¼ of a kilowatt-hour of power (worth about a nickel) per possible discharge or tap from cloud charge separation.
Wouldn't it be a lot more than that? So let's say its a GV at 100kA for 100uS total. That's 100TW. /10000 for seconds and /3600 to get hours, that's 2.7 MEGA watt hours. If you can convert it into usable energy with 40% efficiency, that's still a megawatt-hour.
 

nsaspook

Joined Aug 27, 2009
13,079
Wouldn't it be a lot more than that? So let's say its a GV at 100kA for 100uS total. That's 100TW. /10000 for seconds and /3600 to get hours, that's 2.7 MEGA watt hours. If you can convert it into usable energy with 40% efficiency, that's still a megawatt-hour.
Those are peak values that don't last the duration of the strike.
Your during discharge potentials at any practical collector are far lower than the feeler potential of maybe a GV before initial ground discharge. That extremely fast Δ VI generates the RF signature of the bolt across the discharge channel and you only get the voltage current product at the entry of the energy collector to ground. The lightning ionized current channel resistance from the cloud to your collection terminal will dissipate the vast majority of the total energy. If you try to raise the collector impedance to better match the bolt impedance to increase energy transfer it will simply generate more potential to jump around your resistance because the discharge acts like a current source with an almost unlimited potential to maintain that current. A 500 ohms to ground collector at 30,000 peak Amps results in a 15 Mvolts potential with a return stroke Δ of about 100 kA/μsec that could easily induce a 100,000 volts in a 1 meter long terminal conductor.

https://ieeexplore.ieee.org/document/99117/
 

Wendy

Joined Mar 24, 2008
23,415
You have to dream, which is where innovation comes from. but it is important to keep it practical. I once proposed a scheme to take a giant gyroscope and tap into the earths rotational energy, It would slowly rotate once every 24 hours but that could easily be geared up to what ever speed you wanted, Tapping the tides is more practical I suspect. Interestingly the moon is slowly creeping away from earth several inches per year while slowly slowing the earths rotation. The dinosaurs had an 18 hour day to our 24 hour one.TANSTAFL rules.There Ain't No Such Thing as a free Lunch. Originally written by one of my favorite writers Robert A Heinlein. Entropy in a nutshell.
 
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