Certainly science has looked at this. It's simply impractical for many reasons. For one thing, lightning does not happen that often in a given place. It may seem like it, but if you want a steady supply of power, lightning is very unreliable. The chance of lightning hitting a given spot on Earth, even in a high-lightning strike area is about once in a thousand human lifetimes. Even if you build a high tower, this only raises it to once every few years. Secondly, the power of a lightning strike while impressive to see, is actually not that great. Yes, you get a LOT of power, but it only lasts for about a thousandth of a second. One lightning bolt gives enough electricity to power one household for one month--if you can catch all of it, which is not likely. Much is lost in heat and light to the atmosphere as the bolt comes to Earth. Given the rarity of strikes and the relative small amount of power, lightning is not a good source of energy. Check out the website of Vladimir Rakov, a lightning expert in Florida, who has studied this idea extensively.
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