Geothermal heat pumps are an efficient alternative to traditional HVAC systems. They work by exchanging heat with the more stable underground temperatures via a buried heat exchange system, allowing them to heat and cool homes using less energy. This can reduce heating and cooling costs by 30-40% compared to HVAC. Geothermal heat pumps are also quieter, more durable, and do not emit toxic gases like traditional HVAC systems. However, some people report that the savings are not as high as expected or have issues with maintenance.