Originally posted by Dissident Dan
Here in Florida, the lightning capital of the world, I've been getting thunderstorms on a daily basis. Could lightning serve as a reasonable part of a city's power supply, at least during the rainy season? Across an entire city, I'm sure that you could get many strikes per day in this area, if you make towers that are good at attracting lightning.
Is lightning feasable. I know that lightning has lots of power, but naysayers say that it's just too shortlived to provide a feasible amount of energy. What do you say?
Hey Dan, I spent a fair amount of time playing with this idea many years ago. Here is some information from The Feynman Lectures on Physics; Vol II, Chap 9, pp 2,3,11
The total power available worldwide is about 720 MW; having a typical average worldwide current of 1800 amps at 400,000 volts.
The current in a lighting strike is about 10,000 amperes at the peak, and carries about 20 coulombs of charge.
A typical strike can consist of 1, 2, 5, 10, or as many as 42 separate strikes.
Going by some seat of the pants calcs: if we assume 20 coulombs at 400,000 volts as an upper limit for energy delivered per strike, then we get something like 8 MJ of energy [again as an ideal upper limit]. A typical storm may deliver 100 strikes but over a large area. Even if we could capture all of this energy, then assuming that each strike is really an average of 5 individual events, we get about 4000 MJ of energy; this gives us 1 MW of power for about 1 hour. Not enough to be worth the trouble it would seem. Note that for any real system, if one could be designed and built, we would likely find the efficiencies very low - yielding perhaps 1-5 minutes worth of power in practice [as an example].
The other problem is that if we really somehow tapped this system, we would likely find many unexpected consequences in nature. Lighting is part of a worldwide charging and discharging system that may be an integral aspect of the biology of the planet.