CM: Shallow Geothermal Potential
Introduction
This module calculates the potential of shallow geothermal energy to be used in ground source heat pumps for selected regions in the form of a raster file. The inputs are raster files with initial ground temperatures, depth-averaged ground thermal conductivity and depth-averaged ground thermal capacity.
The calculation module aims to compute the shallow geothermal potential based on r.green.gshp.theoretical according to the G.pot methodology. In this module, the output is the theoretical maximum energy that can be converted in the ideal case without considering the financial and spatial constraints.
Input
The input parameters and layers are as follows.
Input layers and parameters are:
- Vector with depth-averaged ground thermal conductivity [W m-1 K-1]
- Value with the Heating Season [0-365] days
- Raster with the initial ground temperature T0 [°C]
- Value with depth-averaged ground thermal capacity [MJ m-3 K-1]
The advanced input parameters are: * Borehole radius [m] * Borehole thermal resistance [m K W-1] * Borehole length [m] * Pipe radius [m] * Number of pipes in the borehole * Thermal conductivity of the borehole filling (geothermal grout) [W m-1 K-1] * Minimum or maximum fluid temperature [°C] * Simulated lifetime of the plant [years]
Output
Output layers and parameters are:
- a raster map with the geothermal energy potential [MWh/(ha*yr)]
- an indicator of average energy that can be extracted per GCHP system [MWh/yr]
A deeper explanation of the default input raster is available in the Hotmaps repository
It is also worth mentioning that, due to the fact that implementation of geothermal systems is not always possible, especially in very dense city areas, the input raster file does not provide information for several large cities. This is also visible in the output files and is NOT a mistake in the calculation.
Method
The method to define the energy potential is based on the G.pot. The potential of shallow geothermal energy is computed by means of an empirical relationship proposed by Casasso et al. (2016).
The methodology produces a map with the power and the energy that can be extracted, considering the main characteristics of the terrain (e.g. ground temperature/capacity/conductivity) and of the Borehole (e.g. length, diameter, etc).
GitHub repository of this calculation module
Here you get the bleeding-edge development for this calculation module.
Sample Run
Step 1: Select the region
The first step is choosing the area for the calculation. Please note that CMs will be deactivated and displayed in red if no region is selected.
Step 2: Enter the input parameters
After selecting the region, users should click on the "Calculation Modules" tab located in the left pane. Next, click on "CM - Shallow geothermal potential" to display the input options.
The inputs are organised into several levels, ranging from the most basic to the most advanced. The first level of input parameters is referred to as "INPUTS," which is the heating season given in number of days. The basic inputs consist of technical parameters characterising the borehole. Users can give different ground characteristics (e.g. ground temperature, ground conductivity and capacity), if available. It is also possible to define the different characteristics of the geothermal system, like the Borehole geometry. Finally, within the advanced input parameters, users can also define the thermal conductivity of the borehole filling.
Step 3: Run the CM and retrieve the results
Users can start the calculation by scrolling down to the bottom of the inputs section and clicking on the "RUN CM" button. A results tab will appear on the right-hand side of the screen once the run is completed. In this tab, the main indicators are displayed to offer a quick overview of the simulation results.
As previously mentioned, a raster layer is generated as output. This layer shows the potential in different areas. As it is difficult to estimate the potential in dense urban areas, the input raster layer does not provide information for such regions. As a result, these regions are also empty in the output layer.
How to cite
Ali Kök, in SAPHEA-Wiki, CM SAPHEA GEOPHRIES.
Authors and reviewers
This page is written by Ali Kök EEG-TU Wien.
This page is reviewed by Ardak Akhatova e-think.
License
Copyright © 2025: Ali Kök
Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons CC BY 4.0 International License.
SPDX-License-Identifier: CC-BY-4.0
License-Text: https://spdx.org/licenses/CC-BY-4.0.html
Acknowledgement
We would like to convey our deepest appreciation to the HORIZON Europe Actions SAPHEA Project (Grant Agreement number 101075510), which co-funded the present investigation.