Why Geothermal Use what's already there - free & renewable supply of energy It's hard to get much greener than WaterFurnace. The best alternative to heat and cool your home or business, geothermal is... Efficient - With the U.S. National Renewable Energy Laboratory confirming that geothermal heating and cooling is more efficient than conventional residential systems, it only makes sense. Eco-friendly - The EPA determined that geothermal energy is the most Earth friendly heating and cooling system in the industry today. Cost-effective - State, Federal and local government and utilities offer many tax incentives and reductions that makes your investment in geothermal a wise choice. Still not satisfied? You can talk to your neighbors - more and more people are switching to geothermal and love it! Energy and cost savings will vary by region and the type of system geothermal is replacing, but geothermal will always save you more money, smarter, and greener. By using our savings calculator, you can find out how much a geothermal system in the East Tennessee, TN will reduce your energy costs.