It seems like more and more homeowners are adding geothermal energy in our area. I also know of at least 1 winery that has taken advantage of the new technology. When considering something as important as your heat system, I always go to my "well" and get to the knowledge base. In Penn Yan, that "well", for me has been Moravec Geothermal. Any time I've called Rich he's been more that eager to help me understand the process, whether that's drilling for water or for a heat source. They're right here in town 315-536-3911. Tell them Stan sent you!
Here is a link to a calculator that you can play with and see what changes make a diferance.