Author Options:

Why don't they use gigantic leyden jars to collect electricity from lightning and use it to power homes? Answered

Seriously, I had this idea the other night when it was really stormy and lighting out like crazy. Why can't they make large collection centers for lightning, kinda like a leyden jar in principle, with a humongous lightning rod to attract lightning? Lightning is absolutely free, if it was harnessed to power our cities, at least some of them, it would be so awesome! No pollution, no cost to produce, other than construction and maintainance of the facility. You could just plug it into the existing power lines, with some massive step-down transformers of course. So why don't they do this, at least experimentally? Lightning is unpredictable, you say. No problemo, you put this collection thingie in an area where there are a lot of storms, and add a lightning rod-a BIG lightning rod. It's very dangerous, you say. So make it completely automated, no humans required, and put it away from residential and business areas. You say lightning is much too powerful. Nonsense, you can make a big enough facility to contain it. You say I've gone off my rocker...you may have a point there... I know it must be dumb, and have a flaw I am not seeing-do any of you science experts know what it is? Why won't this idea work?


I have often ponded that idea, as have many others. Give it a few years, the potential is there just needs more development... The figures quoted below only represent available data on a relatively unknown power source. Virtually no funding has gone into this potential source so why would any one expect accurate or even relativley reliable indicators of potential? I'm sure if we all started spending our nations cash on researching potentials of alternate energy sources, then they would soon find a viable way to harvest "strikes".

why would any one expect accurate or even relativley reliable indicators of potential?

Because, although not much money has been spent on researching lightning for commercial power, I am satisfied by the currently available data that it is impractical to use. Just an order-of-magnitude figure is enough to demonstrate that capturing the maximum theoretically possible energy from every lightning strike in the entire United States for a whole year would only provide enough power for a few days of electricity usage, and I believe I am grossly overestimating even in that case.

Lightning is deceptive because it produces enormous amounts of power but very little energy, and there is a crucial difference. I'm sure spending more on research would turn up more detailed and exhaustive information but all you really need to know is the approximate amount available. Put it this way- if I have underestimated the power available in my calculations by a factor of 10 it's still not a viable electricity source- that's enough to convince me.

the potential is there just needs more development...

I agree with this for a number of renewable energy sources (wind, solar, wave, etc.) but in this case not lightning. The potential isn't there because lightning doesn't produce anywhere near enough energy.

Bare in mind wind, solar and wave energy was once not known as an energy source. I'm sure the first researchers found those energy sources just as perplexing...

Can I ask, could you say for certain that at no point in even the distant future this could be a potential source of energy...

I understand the data that is available, yet this energy source is not available only due to human short comings of knowledge....

Certainly it can be a source of energy, today. The question is: will it ever be a reliable source of consistent energy? Possibly, and also possibly one day we'll be able to propel spaceships with the channeled force of atomic bomb explosions. Just because you can do something doesn't mean you should, and there are tons of unexplored / unused energy sources out there that'll be a lot easier to exploit.

See my reply in here on atmospheric energy. "What comes up must come down" applies, actually in both directions. The fair weather current is the return of charge from lightning, things have to add up, thus that current tells us how much power is available from all the lightning in the world. And it ain't that much. Meanwhile solar is abundant and a lot less dangerous to harvest than lightning. Nowhere near as much fun though...


10 years ago

Lightning hit leyden jar. Leyden jar go...


Look for the smiley in the boom


10 years ago

I recall some devices that involve sticking "electrostatic collectors" not-too-high in the atmosphere, and being able to collect enough electricity to drive things like electrostatic motors or neon bulbs, even when there is not enough to come close to making any lightning. Alas, electrostatic stuff is pretty-much toy-like; very low power and not very convenient. Harnessing the power of lightning is pretty tough. (arguably, a windmill does it; energy removed from the wind becomes that much less energy that can go into building up the charges that eventually cause lightning.)

Well, when you review atmospheric electricity you see there's a freaking huge potential difference, going from the earth (which is negative) upwards yields 60-100 volts per meter in summer and 300-500 in winter. You may have noticed you are not being electrocuted right now, the amperage is very low.

However, an insulated wire going 2 kilometers straight up would yield a low of 120,000V summer and a high of 1,000,000V winter (crank the numbers yourself, Wikipedia is off a zero). Well then, all we need is a big enough collector up top and we have all the power we need, right? Umm, no, the fair weather current is only 10-12A / m2, roughly 1800A for the entire planet. Thus for the entire globe you'd get about a gigawatt from 2km up.

Of course, there's still power there, and it's free. But, first you'd need a wire that could hang that long without stretching and breaking from it's own weight, from something you could suspend it from (balloon etc) that'd take the weight. And having a much better conductor than even copper would help.

Well, maybe someday it could be done with carbon nanotube cables. Which will be about when they can finally make a space elevator. Which you could make self powering with large enough collectors on the end like a huge nanotube mesh... Wait a minute.


10 years ago

The ever-useful Wikipedia gives the average energy of a lightning bolts as roughly 500 megajoules, or 500,000,000 watt-seconds. This is about 139 kilowatt hours of electricity per strike.

Storing a discharge in a capacitor can only usefully store a maximum of half the discharge energy, so the maximum you could get in your Leyden jar is about 70 kWh.

One kWh costs about 12p (24 cents), so one lightning strike captured in a capacitor is roughly $16.80 worth of electricity (probably less as I would guess US energy prices are lower than UK).

The continental US appears to get about 20 lightning strikes ($336 worth) per square kilometre per year. It has a population density of 31 people per square kilometre, so they would get approximately $10.84 worth of lightning electricity per year.

tl;dr- read the bold parts. One lightning strike doesn't actually involve much energy, and most of this energy is probably wasted as heat in creating thunder, so it's not commercially worth capturing it.

. Handling lightning is almost impossible. For the DIYer it _is_ impossible. Too much power (~100TW) in a very short period of time. The voltage (~1GV/1000' of lightning) alone will put it out of the range of DIY. (figures are very rough, easy to remember approximations) . Plus, how often does any particular place get hit by lightning? IIRC, the Empire State Building (great lightning rod) only gets hit about a dozen times a year.