I'm planning to build a new house and have been researching the feasibility of using geothermal as the energy source.
May I suggest that you contact your local electric company for information on renewable energy heating & cooling. The Federal government is subsidizing residential geothermal installation through local electric utilities. In addition, some of the electric utilities themselves are guaranteeing a not-to-exceed monthly electric bill for a five year period.(The system is said to have paid for itself during that time.)