eli5 why we can’t collect energy from lightning ?

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Saw lot of videos and it seems pretty easy to push wire to thunder clouds to make lightning hit exactly that wire. Why not put some sort of big ass super capacitor and collect this free power for sake of humanity?

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There’s far less power in a single lightning bolt than most people think. Only about one barrel of oil worth.

Then there’s the infrequency of storms. In particular, non-rain clouds are more likely to produce lightning, but then you have off and on seasons for storms. You would have to specifically pick the location with frequent storm activity, much like they select sites with high average wind for wind turbines.

Even capturing it would require specialised capacitors to receive the energy quickly enough, followed by a slower dump of the power into long term storage where it could be released gradually into the grid, but all those processes would loose some of the power to heat and such.

All up, it’s just not economical and anywhere with frequent enough storms to feed it would probably create more power with wind turbines to take the breeze.

Power is energy per time, and our measurements of fulgurites suggest that megajoules of energy make rock in thousandths to millionths of seconds. So a gigawatt is actually on the low side – lightning power may be a thousand times that, reaching into the terawatts, though the average is probably tens of gigawatts.
That’s enough energy to power about a billion houses, albeit only for a few millionths of a second. 

https://www.sciencealert.com/scientists-are-using-fossils-to-work-out-how-much-energy-is-in-a-lightning-strikes?limitstart=1

Energy that comes in short, high intensity bursts at irregular intervals is about the worst possible form of power. You want go get energy from something that provides low or moderate levels of energy constantly and predictably.

Lightning is powerful. That’s bad, because huge amounts of energy heat up whatever you use to collect them and are likely to damage it. This is also true for the equipment and lines that direct the power from the collection point to the grid or to storage.

Lightning is brief. That’s bad because you want to keep a consistent amount of electricity going onto the grid. Lightning would send huge, brief spikes of electricity, so it needs to be stored somehow and released more slowly. That adds difficulty and expense and uses more resources.

Lightning is irregular. You want to be able to plan for the amount of power you will be getting and when you will be getting it. You can’t count on thunderstorms at any given time. That means you’d basically have to build baseline power generation that’s good enough to meet your needs, because you couldn’t count on having lightning around to help out. And then, what’s the point of collecting lightning?

One lightning strike only contains a few hundred kilowatt-hours of energy. Caps store something like a tenth of a watt hour per kilo, so you’d need a capacitor weighing roughly 2,800 metric tons. Hundreds of cubic meters, you’re looking at a warehouse of solid capacitors.

That’s all for the energy equivalent of one full tank of gas in a car. An entire building versus a $50 tank of gas.

While lightning has an immense amount of Voltage, the Amperage is rather low, not to mention the the extremely short time of that energy… The total Wattage is not that high…. It looks powerful, it can start fires and hurt puny waterbag humans, but building capacitors capable of handling that voltage, would not yeild much usable energy.

A powerplant with constant rate of power would produce more usable energy than lightning storms.