Geothermal can certainly be an important energy source. There are a lot of potential energy sources. However, one fact is constantly ignored. Oil, besides being a source of energy, is also the building block of our civilization as we know it today. Thus, we have to look beyond the BTUs an energy source can generate, but we must also look at the products that can be made from the energy source. The list of products that are made from oil is almost endless. To my knowledge, solar, wind, geothermal and other similar energy sources can only produce BTUs or heat which can be used to generate electricity, power electric cars, etc. Thus, we are going to need a mix of energy sources in the future, and oil will have to be part of that list.