Geothermal well. View of a worker opening a valve of a geothermal well in Larderello, Italy, causing steam to spout. This region has high geothermal activity, that is there is an abundance of underground heat in the form of steam which can be exploited. The steam can be used for directly heating homes or buildings. Larderello is one of two locations in the world where geothermal steam can be directly used to turn electricity turbines.