You may think that finding geothermal potential in the subsurface would be easy. But if it were that easy, we’d all be drilling by now! Maps are powerful visual tools — they are where geological understanding begins and where uncertainties become visible.
Geothermal energy is an important component of the energy transition. Much effort is put into exploration for geothermal heat due to lower CO2 emissions and sustainability. For example, municipalities want to know if geothermal can be used as a source of sustainable heat, replacing traditional natural gas heating in their regions. However, geothermal energy production is not possible everywhere: it relies on a favourable subsurface, which in turn requires a variety of specialist expertise. To reduce complex decision-making, PanTerra’s geothermal power maps provide a powerful visualisation of geothermal potential.
Success Factors and Challenges
There are three key subsurface factors that determine whether geothermal potential can be successfully realised. The best geothermal locations require:
All three components are needed to generate high thermal power. This means that finding suitable locations for geothermal development is challenging, as it requires the integration of multiple sources of geological information. We need to know which rock layers are potential reservoirs, where they are, and what their properties are. In order to determine these properties, we need to interpret where the layers occur in the available seismic data, and perform a petrophysical analysis on any wells, to study their properties. From these two analyses, we can meet the requirements of all three success factors.
Visualising Power
Once the necessary data for the success factors have been obtained, these factors can be visualised to show how they vary across the study area. PanTerra uses a proven workflow to integrate all these varied subsurface constituents. The workflow calculates how much geothermal power could be achieved, given the subsurface conditions and a pre-set and constant well design and is then visualised in our geothermal power map. The power calculations used follow a similar method as the standardised tools used by regulators in the Netherlands.
The figure below shows an example of a geothermal power map:
Key Insights Provided by the Power Map
The geothermal power map illustrates the estimated power potential across a study area based on integrated subsurface data. Variations in colour indicate differences in expected power output, while mapped structural features highlight geological controls that influence geothermal performance. We see, for example, a fault block that shows minor geothermal power (blue and purple colours), compared to the neighbouring fault blocks. This low power zone gives a clear answer on the (lack of) feasibility of geothermal in that zone and the reasons behind this can be investigated through individual property maps. Fault blocks further to the west show far more favourable conditions for geothermal development; not only is the power output higher, the area contains less faults – an important factor for safety in geothermal energy production.
Added Value of the Power Maps
PanTerra’s geothermal power maps support informed early-stage decision-making. In doing so, the maps help reduce development risk and contribute to the responsible deployment of geothermal energy. In addition, the maps can be integrated with a broader dataset, for example the surface heat demand. This enables us to make a match between heat demand and supply, making a clear link between surface and the subsurface. This is crucial information for regional planners of provinces or municipalities, geothermal licence holders, and other decision-makers, needing to make informed decisions on geothermal feasibility.