Save Money with Geothermal You already own the property - why not use the free energy source just beneath the surface of your yard? A WaterFurnace geothermal system can broadcast a staggering five units of energy for every one unit of electrical energy used. But what does that mean for you? It means you can condition your Central Minnesota home for far less than your neighbors and friends. The equipment we place in your home is the most efficient geothermal products available. Homeowners can realize savings up to 70% for heating, cooling, and hot water!