What if we could harvest the energy of lightning?
Among the regions with the most thunderstorms each year are listed: the northwestern Venezuela and the far east of the Democratic Republic of Congo. The Guinness Book of World Records lists Venezuela’s Lake Maracaibo as having 28 lightning flashes each minute.
One single bolt of lightning dissipates around a colossal 5 billion joules of energy. To put that in perspective, the same energy would be produced if you could burn 145 liters of petrol in a few microseconds.
Ever since late 1980s has been proposed different methods of capturing lightning energy. One of which was to use the heat energy of lightning hitting the water in order to produce hydrogen which could be stored for later use.
Another proposed method was to use an array of lightning arresters to harness the lightning strike, either directly capturing the electrical with an array of high voltage capacitor bank or indirectly by converting it to heat or mechanical energy.
The third proposed idea was to use large inductors spaced far apart which could capture a small portion of electrical energy by inducing of magnetic field generated by the lightning strike.
But due to unpredictable nature of lightning, none of the proposed methods were practicable. It carries to much energy in a too short amount of time which would damage the harnessing equipment. Also with the current technology it is impossible to predict the exact location of the next strike.
This doesn’t stop us of doing a little thought experiment, for the sake of science and fun.
The average lightning bolt has a voltage of roughly 100 million volts and carries a current of about 20 thousand amperes.
That would give us 100 x 106 x 20 x 103 = 2 x 1012 Watts (or 2 terawatts of energy)
If we assume the lightning would release all this energy in one second, those are 2 terawatts second. Let’s convert them in kilowatt hour so we can use the value in our thought experiment.
212 / 3600 = 556,000 kilowatt hour
The average house uses a daily average of 2 kilowatt hour. Which means a single lightning strike could cover the necessary energy for 31.7 years, assuming we can manage a 100% conversion and 0% loss storage.