| Title | Country Update Report for Denmark |
|---|---|
| Authors | Allan Mahler and Jesper Magtengaard |
| Year | 2010 |
| Conference | World Geothermal Congress |
| Keywords | Thisted, Copenhagen, Sønderborg, geothermal, direct-use, district heating, low enthalpy, absorption heat pumps, sandstone, injection, power storage, Denmark |
| Abstract | The first geothermal plant in Denmark based on deep wells was established in 1984 and later expanded to produce up to 7 MW heat from 200 m3/h of 44 °C, 15 % saline geothermal water with production from and reinjection in a sandstone aquifer at 1,250 m depth. The second plant situated in Copenhagen started production in 2005 designed to produce up to 14 MW heat from 235 m3/h of 73 °C, 19 % saline geothermal water from a sandstone aquifer at 2,560 m depth. DONG Energy has taken out licenses and has erected and operates plants together with local partners. New contacts have been established with a number of towns to look into the options there. A seismic survey has been carried out in Sønderborg to prepare the drilling of a geothermal doublet late in 2009 planned to produce 15 MW heat from 250 m3/h of around 68 °C, 21 % saline geothermal water from a sandstone aquifer at 2.1 km depth. Negotiations have been initiated to prepare the establishment of a geothermal plant in Hjørring producing up to 17 MW heat from 300 m3/h of around 65 °C, 20 % saline geothermal water from a sandstone aquifer at 2 km depth and other towns are interested. The geothermal plant in Thisted may also be expanded further. Preliminary plans exist to erect a geothermal plant in Copenhagen with 11 wells of which some of the production wells can be used for long term heat storage. The heating plan for Copenhagen includes an option to install 400 MW geothermal heating capacity. Danish aquifers are normally not suitable for power production as sufficiently permeable layers are too cold. They may, however, be used for power production based on stored heat from the sun, excess incineration plant heat etc. or heat pumps driven by excess wind turbine power. The number of smaller heat pumps extracting heat from ground water and topsoil has been assessed to around 20,000 with an average COP of approx. 3 and a total heat production at 2 PJ/year. |