Harnessing the Power of Lightning

One of my favorite things to do (when it happens) is sit out on the porch during a thunderstorm at night. It is a magnificent spectacle to watch the flashes of lightning light up the sky; much cooler than a fireworks display.

(<--Credit: Xweather.org)

But beyond its visual beauty, lightning is a massive form of energy: millions of volts discharged within a very brief period (milliseconds). At, It kills an average of 55 people a year and injures hundreds more, except for some old guy in The Curious Case of Benjamin Button:

"Did I ever tell ya I was struck by lightning seven times? Once when I was in the fields just tending to my cows... once when I was sitting in my truck just minding my own business…" (Credit: FreeRepublic.org -->)

Such concentrated energy (over 1 gigajoule) begs to question whether we could harness it into a usable form. Could we use lightning to power our lights, refrigerators, and time-travelling cars (1.21 Gigawatts!?!)?

(Credit: Wiremod)

Electricity from lightning has been discussed on CR4 in the past, and it is certainly an intriguing idea. But as a practical energy solution, it is little more than that due to a number of factors.

Capture

In order to harness energy from lightning effectively, it must first be captured. But predicting and attracting a lightning strike is no easy task. Even with the most ideally placed metal rods, lightning will more often strike randomly. The range of lightning formation can be more than three miles from the actual thunderstorm. What's more, storms are almost always moving, so any capture device would probably have to be portable.

Storage

So assuming we can find a way to effectively and predictably capture lightning - how then do we store it? This is probably the most daunting of tasks. The temperature spike from a lightning strike is massive - peak temperatures reach near 55000°F (30000 K). These temperatures will effectively vaporize any metals that would make up the semiconductors used to collect and handle the charge, unless they were made unreasonably thick. Stepping down the power to a manageable form would also be incredibly difficult and incredibly inefficient. Taking a concentrated, nearly instantaneous surge and storing/distributing it over a long time would require extremely large capacitors and batteries. Considering the gross output of lightning is not very high on a gross scale (accounting for the frequency of strikes in a year in a given area), there would be no payback for this type of technology. And unless something incredible happens in the world of energy storage research, I doubt the devices would be very portable either.

(Credit: Britannica kids -->)

Other Difficulties

Once the storage is dealt with, there's also the shockwave to consider. These waves come as a result of the rapid expansion of air from the extreme heat of the lightning channel, and are the origin of the sound waves (thunder) we hear during a storm. Any capture technology would have to be durable enough to withstand the force of repeated shock waves, which are more than enough to knock a grown man off his feet.

A number of unique ideas could potentially provide solutions for some of these difficulties. Ideas to improve the predictability and consistency of lightning strikes would include methods to further induce charge to an already highly charged cloud; similar to the idea of seeding clouds to encourage rain. Shooting high intensity lasers (which form plasma) into the atmosphere could also be used to precisely channel lightning to a storage device. Other proposals such as charge collection farms would aim to capture and utilize the charges from clouds before they form lightning.

On the surface, lightning seems like a very attractive source of energy - it's highly concentrated, natural, renewable, and in some regions (e.g. Florida) it is readily available. The reality of electricity from lightning, however, is not currently very feasible or safe with current technology. Perhaps in the future technology will open the doors to more possibilities surrounding this incredible natural phenomenon. For now, though, I'll just enjoy watching it from my porch.