Capturing Lightning

Funny, my son and I had this conversation yesterday. We were thinking we'd put a couple thousand high voltage supercapacitors in series, ground one end, and run a line from the other up a flag pole. Then we'd sell the charged capacitors like gasoline. Getting the charge to flow into the capacitors, rather than to the closest ground might be tricky.

We'd get a premium price for our electrons, because they'd be all natural, with minimal processing.

Alternatively, the "flagpole" could be a stack of super capacitors, keeping the high voltage end away from proximity to ground, with only the last few thousand volts being near ground.

Any possibilty of insulating a grounding conductor (say on a TV or radio tower) and running it directly to a capacitor?

Lightning strikes in and around Cape Canaveral are a particular concern to NASA when exposed launch vehicles are in transit to or on the pad. One approach NASA and others have taken is to launch a small rocket, about the size of an air-to-air missile, trailing a grounded wire. The rocket is launched straight up, with the timing determined by electric-field-measuring apparatus on the ground. The wire unwinds from a spool in the rocket much as it does in wire-guided missiles.

Although the wire itself cannot possibly carry the enormous current of a lightning bolt - on the order of 300,000 to 5,000,000 amps (at over a million volts) - the wire vaporizes, leaving a trail highly-conductive of metal ions. Electrically, the ion trail is as effective a conductor as a metal mast extending all the way into the cloud from the ground.

As the lightning discharge propagates down the trail, it ionizes the surrounding air, further increasing the trail's conductivity. Eventually, the discharge follows into the grounded point where the remains of the wire are anchored.

More recently, lasers have been used successfully to ionize the air directly without the use of or need for rockets and wire. After all, once the rocket's fuel is spent the rocket falls back to earth and represents a hazard of its own.

A series of mirrors, placed some distance away from a high-power, horizontal UV laser, are used to direct the beam vertically into the cloud base so that the resulting discharge doesn't strike the laser itself and surrounding facilities.

This technique could conceivably be used to direct a lightning discharge into a capacitor terminal, instead of dissipating a stroke's energy uselessly into the ground.

It seems to me that lightning would be a notoriously unreliable source of energy. In spite of its enormous energy (particularly that of positive strokes, which originate at the tops of thunderheads and can travel over twenty miles before striking an object), the energy of a lightning bolt can be dissipated in a matter of a few seconds by the load represented by a small city. But then what? Wait in darkness for the next bolt? And how long before the capital spent to build the device is recovered?

I say we invest in triangular solar collectors...

-e

Even if the lightning stroke termination could be controlled and directed to the capacitor terminal, the major problem is the capacitor charging time constant compared to the lightning stroke duration. Remember, capacitors resist instantaneous change in voltage and require approximately 5 RC time constants to fully charge. Lightning is an impulse voltage; either positive or negative with about 90% being of negative polarity. Although the mean discharge current of a high current, short duration stroke is around 35,000 amps, the total stroke duration is less than 100 microseconds. To put that in perspective, the time to the first half-cycle crest of a 60 Hz voltage waveform is 4,167 microseconds. Thus, lightning is not a practical source for charging a capacitor even when considering possible multiple strokes and restrikes.

Yup!

Bluestone,

Well put!

"Thus, lightning is not a practical source for charging a capacitor even when considering possible multiple strokes and restrikes."

I would also add that the vast majority of lightning is cloud to cloud, the earth is involved only in a minority of strikes. Even if you could store the energy, you wouldn't collect it that often.

Someday ..... who knows?

Regards, Greg

Can you chain a few capacitors arranged as a loop, each taking it's portion in turn? Would that make sense?

Did you ever consider how exactly the capicitors use the polarization of Diapoles in the Insulation material to store the energy between the plates?

Think that you have a chemical which can be sprayed up un the sky making similar insulating effect and then you stream rays of steel pins just below it- making a capacitor up in the sky.The energy gets trapped there and then. Can you now work out what will happen if you try to take this energy to ground or keep it trapped there for all the time to come?If you wish to take to the ground how exactly you think you can do it?

Did you know that some one in old soviet union had proposed an idea to propel rockets using similar techniques?

Dipoles and magnetization are something I believe not still well understood.What happens if a fast moving rocket is fixed with a cryogenic magnet and pushed thru a Giant steel tube of Iron?There is an instant energy of magnetization (diapole formation) which will produce furthur force to push the rocket ahead? Can you calculate at what speed this will happen? The steel tube will get very hot becuse the energy comes from magnetization. Where exactly it resides normally?

Alok Misra

Huh?

Hi guys,

There's another thread on the same subject just recently.

http://cr4.globalspec.com/thread/5599#newcomments

I was talking to our land and building maintenance supervisor about this thread and he told me something interesting.

Our factory buildings have lightning rods on the roof. One time, a forklift got too close to the wall and severed the ground connection on one of them. As they were inspecting it, he noticed that there were sparks flying off the gap (which was about 1/16"). This was on a clear day, without a thundercloud in sight. The rod is at the top of a 70 meter high building.

So, I guess it might be possible to store some electricity off from the sky and store it for future use.

Try this experiment: string a long wire between two very good, very clean insulators and connect one end of the wire to ground through a neon bulb. The kind without a series resistor works best. (Radio Shack used to carry them - and green ones, too - but if not, cannibalize a neon night light.) The higher the wire is off the ground, the better it will work. If electrical storms are nearby, the bulb should fire quite rapidly. Sometimes the rep rate will begin to increase well before it is obvious a storm is on its way.

Alternatively, connect a large metal plate to ground the same way. The plate must be well-insulated from the ground to minimize leakage. Use three insulators rather than four. Elevate the plate above ground as much as possible. A plate often works better than a wire because of its large surface area.

The electric field between the Earth's surface and the ionosphere can become quite large, up to several hundred volts per meter. The breakdown voltage of a neon bulb is around 65-80 volts, depending on construction and additives (including the addition of a minute amount of radioactive material in some bulbs to lower the ionization potential - a treatment also applied to the tips of lightning rods).

-e

I failed to mention that when using a plate, it is best to smooth the edges and radius the corners. A metal sphere is good, a torus (donut) is better.

Hi there europium, I did this experiment 40 years ago. I have always been interested in Wimshurst and Van der Graaf machines, of which I have one of both. Early in my youth I had come to realise that there was an electical differential between the earth and the sky above, so I conducted a number of experiments to satisfy my curiosity. I lived four stories up in a block of flats at the time so I used a large fireworks rocket to shoot the heavy guage copper wire over to a cluster of tree's that were 50 meter's away. I then climed the tree nearest the wire and wrapped it round a ceramic insulator screwed to the tree. The next thing was to pull the wire taught and wrap it round an insulator near my bedroom window. From there i ran an earth wire of the same guage to earth via my bedroom and a neon tube, the results were spectacular. Even with a clear sky the tube would flicker, so I attached it to a Leyden jar that I had constructed, this was constructed from a 25 liter plastic paint bucket, lined both inside and out with aluminium foil. The results from this experiment were even more spectacular, a large disharge would fly accross the room to an earth placed 1 meter from the ground terminal.

I'm glad you're still here to tell the tale!

Actually, playing with static electricity can be both fun and at least moderately safe. I suppose the naysayers would say, "But wait... isn't all electricity stored in capacitors just static electricity? Isn't there a warning on the back of my TV set that mentions dangerous voltages lurking within, even when the set is off?"

To them I say: "Phooey! What's life without sparks?" (OK, no I don't really say that -- don't read this and then discharge the capacitor in your TV though your body!)

My great uncle had a huge house in an old posh neighborhood outside Detroit. This Tudor house had a full basement with several rooms, and the supports for the first floor were all built into arches that separated the rooms (instead of the typical steel posts used these days). So the place had the feel of a cathedral, or Frankenstein's lab, depending upon perspective. Tilting perspective toward that latter was that fact that my great uncle had several Van der Graaf generators, Tesla coils, some Jacobs ladders, etc. and other cool electrical stuff to play with. I was probably only 5 - 8 when I last visited him, but still remember the thrill of having a fluorescent tube held in my hand mysteriously light up.

That was INSANE! I've got goosebumps all over me!

If Benjamin Franklin had any idea of how powerful lightning was, he might have thought differently doing his kite experiment the way he did. You, on the other hand, already knew and you still did this?! It's was crazy!...loved your story though .

Hi Vulcan. Of course I knew, but if nobody dares to experiment with dangerous things then we will have no advancement in the world. Think of all the other dangerous experiments what have been undertaken by scientists and other people who have ever lived to tell the tale, most of them survived. I have since executed more dangerous experiments with static electricity and I am now 62 years old, if I die trying then at least I did something other than sit on the sofa at home doing nothing. Two years ago I bought 100 capacitors as used in flourecent strip lighting, I then connected them in series and earthed them. Next, I charged them from a small Van der Graaf generator I had constructed, The results were spectacular, I had a lightning bolt jump 3ft from one terminal to the earthed terminal. Of course, I made sure that I took all possible steps to ensure that I would not be harmed in any way, and soon I am going to make my own large scale capactors to see how far I can stretch this phenomonen.

While I agree that people from long ago did dangerous things on the road to discovery. They, on the other hand, had no idea of the dangers.

I once read of one scientist, I think it was Newton, who took to tasting his chemicals to identify them! And several scientists reportedly lost their lives duplicating Franklin's experiments!

Of course, if you know what you're doing and take every precaution then have at it. You've been lucky too because, sometimes, even the most careful people get hurt because:

• they still make mistakes
• other people make the mistakes for them
• mother nature or lady luck suddenly decides to throw a curve ball

What's the point about all these experiments you've been doing on high voltages anyway?

When I was in the Boy Scouts, I hooked a smal DC motor to ground (earth) and connected the other terminal in series with a selenium rectifier which was connected in series to a 150 foot long antenna (the same antenna for my crystal set radio). The motor spun a small propeller which provided a cooling breeze. My Scout Leader was suitably impressed and recommended me for the Electrical Merit badge. Later experiments with a longer antenna connected to a flourescent light and a homemade galvanometer provided me a primitive way to "grade " thunderstorms by their electrical activity. I was often abel to detect a storm long before the lightning and rain announced its arrival and could "measure" the residual electrical activity after the storm had passed.

Well, I guess what all this says is that there is a possibility of harnessing electricity from the sky. It won't be constant, I'm sure. More like wind power in characteristic.

I'm not so keen on using the same setup (DC motor to ground with a 150 foot antenna) in my house. I'm not knowledgeable enough to install safety gadgets to the system that would prevent a lightning strike from damaging not only the equipment but from jumping from the system to me or one of my household.

Maybe I could put everything in a separate shed, with the DC motor driving a generator.

Nature Captures most of Lightning strikes' energy and puts the net product to good use for all of us to survive.

By converting N2 &O2 to NO₂ >NO₃ >HNO₃>NH_3.

These are Free fertilizers for Agriculture and plant life.

So no individual profit--maybe--but common Good is already being done.

Seems there might be a little water vapor (H₂O) involved too.

Ozone is another natural product of lightning.

Practical use: accumulate the ozone sell it to the hole in the ozone layer people and buy some batteries.

About 50 year back, I was 9 years old, Gyro Gearloose (the inventor in the Donald Duck magazine), proposed already to capture the energy of a lightning strike by using a kite. Since that time this idea has been in the back of my mind. I think the idea is great, but the currents involved are too huge to handle. However, it is not necessary to capture the full strike. It might be an idea to divide the current in two paths of which one is limited to a level we can handle. The latter current can be used to charge a capacitor. It is not difficult to do some small experiments. To make it easy, as a start, you can try to capture the energy from the voltage induced by a strike on a large coil (you need a coil, a diode and a capacitor). However, one must be aware that most of the energy is emitted during only a few micro seconds.

It might be also very instructive to read back the magazine ....;-))

Even centuries after Ben Franklin's experiments, the jury is still out re the effectiveness of lightning rods, as well as their mode of operation. About 50% of the people argue that they dissipate charge before a strike -- making a strike less likely. The other half argues that they redirect the energy of the strike itself to ground and away from the protected structure. (When one considers that lightning strikes on beaches can melt sand into tubes, then the wires often used to ground lighting rods and antennas seem pretty feeble: the wires should be routinely vaporizing, one would think.)

In the sailing world, those in the majority believe that the mast and standing rigging should be bonded together and grounded to a plate on the outside of the hull (under water). But those in a large minority believe that doing so increases the likelihood of your getting hit (the lightning rod "attracts like a lightning rod") and also increases the likelihood that you will be dis-masted when hit, because the large currents will melt the standing rigging (this has, in fact, occurred as the result of lightning strikes).

Cloud base altitude can be fairly low for some thunderheads. It seems reasonable that if one put a plate at cloud base height (how on earth would you keep this moving with the cloud? balloons? airship? hmmm -- the updrafts and downdrafts are pretty hard to contend with) that you could collect the static electricity as it is generated in a long group of series-connected capacitors, with the (very long) ground wire on the end of that series.

just passing by and read this thread, Fascinating! :)

all the best each, YT2095.

Here's the closest thing I've seen to capturing lightning:

http://205.243.100.155/frames/interesting.html

Capturing, as in "eye-candy" captive ?

It can also be a practical demo for fractals, if you really stretch it