Geothermal energy potential in Norway
Information and references are presented related to the potential of exploitation of geothermal energy in Norway. Mainland Norway consists of old lithology where there is no clear correlation between the local geology and the surface (vertical) heat flow, generally used for assessing the potential for geothermal energy exploitation, although larger areas, such as the Oslo graben, is well known to have higher potential. There is therefore a general need for local measurements of surface heat flow in Norway to develop an understanding for local potential. Such measurements may together with knowledge of the local geology provide a basis for assessing exploitation potential.
The Geological Survey of Norway maps and provides data related to Norway's geology.
The Geological Survey does not cover heat flow data. Sources for such information may be found in the published literature. Some relevant references are provided below. On a nationwide scale, the geology is relevant for the understanding of geothermal energy potential.
NVE provides information on how we use the electrical energy in Norway. In this link, they describe the consumption for heat and cooling in Norway was around 73 TWh/year in 2018. 67 % of this (49 TWh/year) is run by electrical energy. https://www.nve.no/energi/energisystem/termisk-energi/varme/
For a more thorough report on how we consume the electricity in Norway, see: https://publikasjoner.nve.no/rapport/2018/rapport2018_87.pdf
Can this be reduced? If heat is needed, the question is why using electricity at all? There are large gains by incorporating heat supply from the ground as described in this report from Asplan Viak, 2020: https://publikasjoner.nve.no/eksternrapport/2020/eksternrapport2020_08.pdf
Study performed for the Norwegian Water Resources and Energy Directorate (NVE) by Asplan Viak, supported by Xrgia AS and Statistics Norway (SSB).
The study shows the potential for geothermal heating, in Norway. Background is provided for assessing how much ground heat can be extracted.
Slagstad T, Balling N, Elvebakk H, Midttømme K, Olesen O, Olsen L, et al. Heat-flow measurements in Late Palaeoproterozoic to Permian geological provinces in south and central Norway and a new heat-flow map of Fennoscandia and the Norwegian-Greenland Sea. Tectonophysics. 2009 Aug;473(3-4):341-61.
The paper presents heat flow in 9 sites across Norway based on measurements of thermal gradients, thermal conductivity and heat generation, and corrected for palaeoclimatic and topographic effects. Data from 15 wells between 400m and 1000m deep has been used.
The paper further presents heat-flow maps of Fennoscandia and the Norwegian-Greenland Sea based on a compilation of nearly 1000 heat-flow measurements.
Results indicate heat flow between 50 and 60 mW / m^2 on mainland Norway. Hurdal and Fredrikstad have the highest heat-flow values. The measured data does not indicate a clear relation between heat-flow and geological parameters on the local geographic scale. On the continental-scale, for Fennoscandia and the Norwegian-Greenland Sea, such a relation is however apparent.
This article discusses the energy potential for geothermal heating in Norway, estimating a total potential of up to 23 TWh of energy savings per year through energy efficient buildings exploiting the full potential of heat pumps (i.e. using the ground as a heat reservoir). See also figure and paper reference below.
As a reference, the total energy consumption of Norway was in 2020, 304.2 TWh, according to Energi Norge.