| Title | Shallow Geothermal Energy – History, Development, Current Status, and Future Prospects |
|---|---|
| Authors | Sanner, B |
| Year | 2016 |
| Conference | European Geothermal Congress |
| Keywords | geothermal heat pumps, UTES, history, development |
| Abstract | The paper gives an account on the early steps towards use of heat pumps, and then focuses on the situation in Europe. Details are given on R&D-activities in Germany from the 1980s on, and on the related work in IEA-cooperation. Reports and findings from conferences of that time are highlighted, as well as steps towards guidelines and standards. Some examples of milestones in practical application are given. An assessment of the current status, both in technical development and market, and some cautious expectations for future development complete the picture. Taking advantage of the steady temperature inside the earth goes back into prehistoric times, when caves or holes were used for storing food and for living, both in cold and hot climates. However, active use of this thermal energy reservoir required a tool for changing temperature, the heat pump to increase it, and the chiller (or a heat pump in reversed mode) for decreasing temperature. Practical application of the heat pump process was already done in the 19th century, with the example of the steam generation in Ebensee salt works in Austria. The first claims on a heat pump extracting heat from the earth were made by Heinrich Zoelly in a Swiss patent of 1912. However, the first documented application in reality dates from 1945, in Indianapolis, USA, and in Europe the first reports on ground-source heat pumps are from the 1960s. R&D on geothermal heat pumps had a first boom in the 1950s in USA and Canada, and after the first oil price crisis in 1973, it started in Europe and Japan, and resumed in North America. Today, grounds source heat pumps and underground thermal energy storage are an accepted part of sustainable solutions for providing heat or cold, and the number of ground source heat pumps in Europe alone rose to over 1.7 Mio in 2015 (Antics et al., 2016). Furthermore, universities, research institutes, and private companies all over Europe are active in shallow geothermal R&D today. |