A SINGLE bolt of lightning contains around 5 billion joules of energy. That's 5,000,000,000 watts dumped into the earth in the fraction of a second. There are roughly an average of 8.6 million lightning strikes a DAY on the Earth. That's ALMOST 100 lightning strikes a SECOND, so 500bn watts a SECOND are discharging into the earth. In 2004 16,424 billion kilowatthours so 16,424 x 3.6 megajoules so 59,126,400,000 joules of energy FOR AN ENTIRE YEAR. So 11 bolts of lightning dump more energy into the earth than the entire electricity generated in 2004