Nasor isn't around at the moment, so I'll attempt the calculation myself. Please double check my figures. A Terawatt is 1,000,000,000,000 Watts. 1 microsecond is 1/1,000,000 of a second. There are 3600 seconds in an hour. So the number of kilowatt hours in 1millisecond of the lightning is (1,000,000,000,000)/ (3600 times 1,000,000) = 277.8 Kwh and in 30 milliseconds =8333 Kwh Even if you cut that down to allow for the Terawatt being peak wattage, say we half it, making 4150 Kwh, that's considerably more than was calculated before. Benny, your calculations would be right if the life of a lightning bolt wasn't so short. If it lasted for an hour, and you could capture the energy, you would have a tremendous store of power. But it doesn't. It lasts for 30 microseconds. If a lightning bolt contained as much energy as you think it does, it wouldn't just blow trees apart by turning their sap to steam, it would vaporise them. Also, look at a typical lightning conductor. Do you think that a half inch thick copper wire could carry the current you are talking about? Here's a table of wire gauges: http://www.powerstream.com/Wire_Size.htm Carry on if you wish, but I think that people are losing patience with you.