Drill-Well LLC offers both "closed loop" and "open loop" geothermal well systems. Closed loop geothermal systems recirculate water through HDPE (high destiny polyethylene) pipe placed vertically in the ground to extract energy from the earth. Open loop geothermal systems pump well water to extract energy from the earth. While open loop systems have less up front cost, they can only be utilized in areas with sufficient ground water available. Both types of systems are generally 30% to 70% more efficient than conventional systems. Geothermal is also a great way to reduce your carbon footprint and the payback period is much faster than solar.