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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16 Answers

Anonymous 0 Comments

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.

Anonymous 0 Comments

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?

Anonymous 0 Comments

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

Anonymous 0 Comments

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.

Anonymous 0 Comments

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.

Anonymous 0 Comments

So, we also get plenty of sun, and although it works, it’s not perfect because solar power is not constantly available and we don’t have a nice and efficient way to store that energy.

Lightings/thunders are even less reliable than sun… you get the energy only when there is a storm and if you get a thunder.

Plus, all the other points raised by other comments.

Anonymous 0 Comments

We could collect the energy in lightning if we wanted to. But it’s unpredictable, difficult to convert from millions of volts down to 240 or 120, and the biggest answer as given by others, there is only about 50 to 100 GBP contained in each bolt. So for the same cash outlay, you’ll get much more electricity back if you spend it on solar panels or wind turbines.

Anonymous 0 Comments

So Google says a lightning bolt delivers about 300,000,000 (3•10⁸) volts and supplies about 30,000 (3•10⁴) amps of current. This gives you 9•10¹² watts. A lightning bolt apparently flashes about 4 times in the span of roughly 0.2seconds for 0.00003 s (3•10’⁵) each for a total time of 12•10`⁵ seconds of power delivery.

So the energy delivered in this lightning strike is 108•10⁷ watt•seconds. Power is typically sold and measured by the kilowatt•hr so let’s convert it to that for comparison

Convert watts to kilowatts by dividing by 1000 to have 108•10⁴ (the numbers are small enough to type now, so 1,080,000 kW•seconds. Convert seconds to hours by dividing by 3600 to get 300kW•hr of energy.

For reference this could run an 1100W microwave for just over 11 days. A TV uses a little over 100kW•hr per year, and each Bitcoin transaction uses about 700 kW•hr.

Using the average power cost in the US of 12¢ / kWh, the amount of power produced would be worth like $36

To compare to other means of power generation, a barrel of oil produces about 1700kW•hr, a ton of coal produces ~2500kW•hr of energy

For the small amount of energy created, and how seldom lightning would actually hit this generator, it wouldn’t be worth it. It’d be better to invest in a wind turbine that can produce enough power to run several hundred homes

Anonymous 0 Comments

We don’t know where exactly the lightnings going to hit and we don’t have anything to store that much of energy

Anonymous 0 Comments

What are you talking about? Doc harnesses that 1.21 jigs watts no problem.