Currently, geothermal energy is increasingly becoming a ‘hot topic’ in political discussions on future energy supply. In the face of rising fossil fuel costs, geothermal energy offers secure, long-term availability along with the capacity to meet base load needs. Its flexible range of applications in heating, cooling and electricity generation is also leading to an increase in the number of plants installed worldwide. Heat pumps can be used with shallow geothermal energy systems as well as for heating and cooling, making them increasingly attractive for use in residential and commercial properties. An optimally configured heat pump can improve a building’s indoor climate and reduce heating and cooling costs.