Save Money with Geothermal Free energy is waiting to be used and it's only several feet underneath the surface of your backyard. What are you waiting for? A WaterFurnace geothermal system extracts an astounding five units of energy for each electrical unit of energy used. But what does that mean for you? It means you can condition your Wilmington home for far less than your neighbors and friends. The equipment we place in your home is the most efficient geothermal products on the market today. Homeowners can actually get savings up to 70% for heating, cooling, and hot water!