Longevity and power density of intermediate-to-deep geothermal wells in district heating applications

This paper assesses the potential of intermediate-to-deep geothermal wells for district heating purposes in non-hot spot regions as a means for replacing carbon-intensive heat sources. In analysing the problem of heat transfer from the bedrock to a flowing coolant in the well, we perform parameter scans to assess the longevity and power density of different-size wells and derive analytical estimates to explain salient characteristics of the well behaviour. The results are then utilized to illustrate how intermediate-to-deep geothermal wells would compare with the requirements of typical large-scale district heating systems, by using the city of Helsinki in Finland as an example.