With current technology, you can not use flash energy as an electrical energy source. Simply because lightning has a tremendous amount of energy and it is very difficult to collect that energy because when lightning strikes, it generates six times the heat on the sun’s surface. Also, the amount of energy contained in the flash is very large and therefore you would need a number of batteries to store that energy.
Also, flash is neither AC nor DC. It is a voltage spike and basically takes only t = π / 2 or a little more, ie it does not complete even half a cycle. That’s why you need devices with extreme power electronics designed for such high power ratings to handle the flash tip and convert it into storable energy. This is not possible with currently available technology.
Why can’t we harness lightning energy?
- Lightning is caused by the different electrical potential of sky (clouds) and ground. This potential rises to the point where it can ionize the air and provide a way to offset that difference.
- Trying to harness that power at this moment would be tantamount to trying to use nuclear energy the moment a bomb explodes.
- It is more rational to harness the electrical potential before a lightning strikes. Not only would this be safer and easier, it would also reduce the damage caused by lightning strikes.
With a high lightning rod with a sharp tip, a small current flows from the tip and a larger one during a storm. In the atmosphere there is a constant electric field of 100 volts per meter, which is maintained by the thunderstorms of the world. Since air is not a bad insulator when it does not have a power outage, it is difficult to create a complete circuit from which you can gain energy. A conductive object easily changes the electric field in its environment.
It has been proposed to use the energy contained in the flash to generate hydrogen from water, to use the energy from the rapid heating of water due to lightning, or to use a group of lightning rods to utilize a blow either directly or by conversion heat or to supply mechanical energy or use inductors that are so far apart that a safer part of the energy can be trapped.