How was geothermal energy discovered?
I guess people would have just seen hot water coming from natural springs. This was known to the ancient Romans and probably well before that.The people who lived around Vesuvius in southern Italy were used to finding hot springs and steam outlets in that area, but in those ancient days nobody knew about electricity. Much later when Icelanders colonised Iceland they would have found hot springs and geysers. It was a matter of developing power generation before people with these assets decided they could use them. There is a sizeable installation at Larderello in Italy.The US has about 3000 MWe from geothermal, though this is only 0.3 percent of the total in the country.
