Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: waytogo on 23/10/2012 09:08:57
-
If yes: HOW? // If not: WHY?
Tnx.
-
It might just about possible in a technical sense but the energy in a lightning stroke is in a very inconvenient form a hi voltage and power for a very short time.
It would be hopelessly uneconomical to build and operate equipment to do it
-
How about tapping it before it 'explodes'? Don't really see how to do it but still?
-
Storing electricity is quite hard to do under normal circumstances - and lightning is at the rather extreme end of "normal"!
You lose a lot of power on charging and discharging a chemical battery.
- There are limits on how quickly you can charge them (a real problem when a lightning bolt typically lasts for only 5 to 30 microseconds).
- Battery technology is said to be progressing at about 5% per year, well behind the 40% compound growth experienced by electronics.
- This is why many solar farms are trying overnight heat storage rather than use chemical batteries.
Capacitors offer a more rapid charge/discharge cycle than batteries, and some people are looking to team capacitors and batteries. However, capacitors tend to explode when you apply too much voltage, which breaks down the dielectric. This is a problem with lightning, in that it has a potential difference just before the strike of roughly 1 million volts per meter.
Another challenge is that lightning is seeking the shortest, lowest-impedance path to earth. To absorb the most energy from the lightning, you want something that has a moderate impedance. If that impedance is higher than air, the lightning will just go around your energy-collection device.
There are also some problems with getting lightning to strike just where you want it. A tall tower on a high hill will help - but it is just as likely to strike another hill. One rule of thumb is that a lightning rod will only attract lightning that was going to strike within a 50 meter radius.
To extend the collection range, there have been experiments trying to attract lightning to a tower using high-powered lasers to ionise a path through the air.
I am not sure that I would want to be standing near a device that has just generated an electrically conductive path to a cloud at hundreds of millions of volts! I wouldn't want any expensive electronics near it either, as lightning tends to "fry" electronic devices that it touches.