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 deliver a staggering five units of energy for every one unit of electrical energy used. Still not convinced? Look at it this way. You condition your Knoxville home with free energy - for far less than your neighbors using traditional heating and cooling methods. We put in your home geothermal products that utilize that free, clean energy lying in your backyard. Grab a hold of savings up to 70% on heating and cooling your home - you can even heat your water for no cost during the summer!