Resources Geothermal is an excellent way to heat and cool your Defiance home or business. We are sure you have questions on how geothermal can work for you. Don't worry, we're here to help. You'll find a lot of valuable information and resources here... Geothermal Incentives F.A.Q.s Still have questions on how a geothermal system can help you here in Defiance? Just give us a call or email us and we'll be happy to help you on your path to a more energy efficient and cost saving way to heat and cool your home or business.