FACT #36

Since the late 1980s, there have been several attempts to investigate the possibility of harvesting lightning energy. A single bolt of lightning carries a relatively large amount of energy (approximately 5 billion joules or about the energy stored in 145 litres of petrol). However, this energy is concentrated in a small location and is passed during an extremely short period of time (microseconds); therefore, extremely high electrical power is involved. 5 billion joules over 10 microseconds is equal to 5×1014 (or 500 trillion) watts. Because lightning bolts vary in voltage and current, a more average calculation would be 1×1010 (or 10 billion) watts. It has been proposed that the energy contained in lightning be used to generate hydrogen from water, to harness the energy from rapid heating of water due to lightning, or to use a group of lightning arresters to harness a strike, either directly or by converting it to heat or mechanical energy, or to use inductors spaced far enough away so that a safe fraction of the energy might be captured.