i am sure there is a fortune in this proposal but how do we go about harvesting the energy released from lightning i’ll split the profits
The trouble is in storing the electricity. In fact, that’s a big part of the energy problem we have now. For example, California with its big energy crisis likely produces enough electricity in a 24 hour cycle to deal with all its needs. The problem is, late at night, nobody is using the electricity, and it doesn’t just sit in the lines waiting.
Currently, there is research being done on what is called Superconducting magnetic energy storage (SMES). This technology is essentially a gigantic superconducting electromagnet in a cryogenic bath. It pulls electricity out of the system during low use hours and stores it by letting it circulate in a virtually zero resistance coil until it is needed (say, during peak use hours). Just a bit of trivia here, the magnet is so powerful, that the system has to be enclosed in like a 1 mile radius fence, because the magnetic field could be very dangerous within that area. Anyway, the Japanese are very interested in this technology, and it seems like a pretty cool idea.
I realize I’ve drifted way off topic, but an essential problem in harvesting lightning is the inability to store it for later use, and really, in terms of how much power is used in this country, it is unlikely that harvesting lightning would have a great impact on the supply even if we could store it.
Collecting it in the first place could be a problem too; you see lightning strike, go and set up your collecting conductor, but lightning never strikes twice*, so you’re stumped.
*Yes, I know this isn’t true, but the fact remains that it will be difficult to collect.
Plus, isn’t there something about the high voltage/frequency of lightning that’s going to make it hard to convert to useful current?
As regards storing it (Assuming you can collect it and convert it to useful current, you could use it to pump water from a lake to an elevated reservoir (i.e. convert it to potential energy), then run the water back through a hydroelectric turbine when you wanted to get the energy out.
There’s an electricity generating station that uses this principle in the UK; it buys cheap electricity from the grid off peak, uses it to pump water as above, then generates electricity from it at peak times and sells it back to the grid for a fat profit. Nice.
Another problem with collecting lightning’s power would be for the equipment to go from off to 300 kilovolts of power back to off in a few seconds. I can’t picture much equipment handling that kind of loading.
Wouldn’t it be easier to store the electrical charge before the lightning dissipates it?
Such power stations are in use. But why build a lightning collector plus power storage system, when just the power storage system itself would be equally useful? That is, if we build a storage system, we have plenty of surplus power to store in it without having to build lightning collectors.
Besides, how long does a lightning last? Less than a second, definitely. Can you imagine a pump that works that fast? And please don’t say “build another power storage system to power the pumps.”
You can get lightning to stike the same place more than once and when you want it to very easily, scientists do it all the time to study lightning.
You fire a rocket carrying a very thin wire up into an cloud displaying electrical activity. Once up there the lightning discarges through the wire until it reaches earth.
If you could get the storing thing happening, and with the frequencey that electrical storms occur I am sure that you could run a small village, Don’t even think large scale.
PerfectDark
I think you guys are missing the point.
From NASA:
1012 Watts over 30 microseconds??? Do you realize how insignificant that is? One captured lightning stroke, captured and converted at 100% efficiency, would barely power a standard 3-bedroom US house for 45 microseconds. When you consider the time, effort, expense, danger etc. in trying to catch and use the lightning, it really just doesn’t seem worth it.
So this is what I wrote. Then, I did some other web searches:
From Canadian Geographic
OK, this agrees in general with the NASA link. But then I found this link, from ABCNEWS.com, which is clearly at odds with the scientific links above (how unusual is that :rolleyes: ):
From ABCNEWS.com
OK…we jump from 1000 W to 1,000,000,000,000 W in ABCNEWS land, and also from 20,000-30,000 C to 270,900 F exactly for its temperature. I can’t tell where their information comes from, as this science column (like most) is completely uncredited and unreferenced. Of course, there are a couple long-time posters here who will jump on me if I try to point out possible scientific ignorance among journalists, so I won’t comment on that, and will instead look further.
So then, I find from this little site, an uncredited claim of:
OK…maybe this clears things up. Maybe people are confusing POWER with ENERGY here.
POWER is essentially the flow rate of ENERGY. A common measure of power is in Watts, whereas a common measure of energy is in Joules. You can also get from power to energy by multiplying (integrating, if you will) power by time. So if you have X power delivered over Y time, that is an energy.
If we take the NASA website as being the most accurate, and take 30 microseconds as the duration of a lightning flash, and assume 100 million volts and 10,000 amps we get a POWER of 1 trillion Watts, but over 30 microseconds we get an ENERGY of 30 million Whr, or 30,000 kWhr of energy. Well, that’s not so bad - one bolt could power about 25,000 standard US homes for one hour.
Note though that NASA says that the average peak power is 1012 Watts, over the 30 micoseconds. So it is possible that the peak of 100 millions volts and 10,000 amps only occurs over a few nanoseconds, thus bringing the energy released way down.
And then, here’s another site that gives some very specific details about lightning, including electron densities and power conversion factors, but its numbers disagree with all of the ones above.
FTR, according to NOAA, there are about an average of of 21,746,000 cloud-to-ground flashes per year.
So overall, damned if I know which is the right answer.
It seems very fishy that they’d quote 4 significant figures on such a fuzzy topic. I think it’s supposed to be 10^12 watts, which would be consistent with your other quotes. The formatting must have gotten lost on the way somewhere.
I’ll bet you’re right, scr4!
“I’ll bet you’re right, scr4!” says Anthracite, pointing out the possible scientific ignorance among editors.
Given that the URL http://www.ghcc.msfc.nasa.gov/lisotd_old.html for that NASA link contains the word “old”, that page is probably obsolete. This is supported by the presence of another NASA page with the same text formatted correctly:
If you’re going to collect the energy in thunderstorms, you’d be way better off to just figure out a way to use the stored energy before it’s released as lightning. After all, the storm is basically a giant battery, with the atmosphere acting as a dielectric. When the potential gets so high that it breaks down the dielectric, you get lightning.
Any time you move through the air, you generate electricity. When Dirigibles would come in for landing, they had to discharge their built-up electrostatic energy with a big lightning rod before touching down. When fueling aircraft, you learn to always attach a grounding strap first, because an airplane that just landed can be carrying enough electrical potential to cause a bolt of electricity to jump from the skin to the fuel nozzle, causing a fire. So you ground it first.
Personally, I’d ignore that ABC story entirely…
The figure that they give there is twenty-six times the temperature of the Sun’s surface. Somebody’s pulling numbers out of various bodily orifices, here.