Correct me if I'm wrong, but I think geothermal works where the nature has done the work for us. Where there are underground springs that turn hot and the water comes up steaming.
If you plan to drill the holes yourself, you have a lot of work to do. Drilling is expensive, and a single hole will not get you a lot of heat after the initial honey moon period.
If you plan to drill the holes yourself, you have a lot of work to do. Drilling is expensive, and a single hole will not get you a lot of heat after the initial honey moon period.