Can We Power Cities with Lightning?
There is so much power in a thunderstorm. Some places in the world are renown for the sheer number of lightning strikes they get a year. One of these places is Tampa Bay, Florida. A large city that needs a lot of power and happens to be in one of the most struck places in the world. This lightning city could theoretically harness the incredible power of lightning to power their city.
But there’s a catch…Lightning is ridiculously unpredictable. Even if you have the most lightning strikes if the lightning hits the wrong place you can’t do anything with the power. And each lightning attractor would need a ton of infrastructure to handle the massive power going from the sky to the storage system in fractions of a second. This storage system would have to mostly be capacitors if it wanted any hope of actually capturing the power, but capacitors have nearly no storage capacity so while their charge speed is ludicrously fast (like lightning-fast) it would not be able to store much of the power per unit. So there would have to be a lot more capacitors. And these would then have to discharge into the power grid of the city at a controlled rate or a large battery bank
But that doesn’t really make sense. For one how are you to be certain the lightning will strike at that one place. I mean you could put a really tall tower up to increase your chances, but then you have to have a storm nearly directly above you and hit at least a couple of times a month, probably more to make this make any sense given the investment needed to actually harness the power of the storm.
Hmmm. This isn’t making too much sense. At least electrically. There are a ton of other problems I didn’t even mention like the need to ground a large amount of the lightning to keep from frying the capture system and how difficult any longterm storage would be.
Electrically this would be a very difficult proposition.
There is, however, another way: Heat.
Heat or more specifically steam is our primary method of converting chemical, atomic, and most other fuel storage into electricity. We heat up essentially water and use the pressure to turn an electric generator and make power. For lightning, we would need to run nearly all of the power from the lightning strike to a water reservoir where it would enter through thousands of steel heating filaments and vaporize as much of the reservoir’s water as there is energy in the strike. This way many lightning rods can be used to generate steam for the system and it can be done for far cheaper compared to a capacitor bank. Additionally, this electricity can simple plugged into an existing power plant already outfitted with the water reservoir and the turbine. The electricity would just run through an installed heating filament array and allow the power plant to save money on their fuel costs while still generating profitable electricity.
There have been attempts to harness the power of lightning to varying degrees in the past but no one has found a profitable method of doing so electrically. Furthermore, we do not really know how much power is in a lightning strike. Sure there is a lot of power, but sometimes there is way, way too much power. In 1969 the Apollo 12 Spacecraft was struck by 100,000 amps during take off. Lighting has a large charge window from 10,000 amps all the way up to 200,000 amps. This means that whatever system you design to capture the energy needs to be able to handle even the outliers or risk blowing up. This isn’t such a difficult thing to do, but because of the speed of lightning, everything needs to be in place and ready to handle the strike before it happens. Lightning is unpredictable the science of predicting when it happens is still in its infancy let alone predicting how strong that strike will be to prepare the storage system and water reservoir for the influx of power.
But there are some indicators seconds before lightning strikes that it will strike. There is a strong positive charge in the soon to be struck area could help predict the strength of the discharge depending on the strength of the positive charge. If the lightning rods that are connected to the power generating infrastructure also had a sensor on them to detect this positive charge the system would have a precious few seconds to prep for the level of power it is about to receive. just a second or two warning would be plenty of time for the valves and electronic controls to be ready for the strike and to optimize the power production from it.
Without the ability to predict the strength of the bolt the electricity would be set at a maximum. If it did not meet that maximum it would be highly inefficient and if it went over that maximum all the power that could not be converted would be wasted, put in the ground. An early warning system would make something like this viable in places where lightning is as common as rain.