geothermsim : Scalable semi-analytical heat transfer simulation of geothermal borehole fields

What is geothermsim?

geothermsim is an open-source semi-analytical transient heat transfer modeling tool for geothermal borehole fields. The method uses high-order piecewise polynomial approximations of heat extraction rates along line trajectories representing the boreholes and evaluates ground temperature changes from the spatial and temporal superposition of heat source solutions. Quasi-steady-state variations of heat carrier fluid temperatures inside boreholes are evaluated by leveraging the multipole method to build and solve a system of ordinary differential equations.

geothermsim is written in Python and based on JAX. Its main goal is to allow large-scale, hardware-accelerated, detailed simulations with support for automatic differentiation.

The paper introducing the modeling approach of geothermsim is currently under review. An arXiv link will follow soon.

Version 0

geothermsim is in its initial development stage. The API is subject to change as features are added. Version 1 will release when the API is stable and documentation and unit tests are implemented.

Documentation

Documentation is currently in development. Jupyter notebooks that reproduce the results of the introductory paper can be found here.

Installation

Quick start

Users - Install the latest release using pip:

pip install geothermsim

Alternatively, download the latest release and run the installation script:

pip install .

Developers - To get the latest version of the code, you can download the repository from github or clone the project in a local directory using git:

git clone https://github.com/MassimoCimmino/geothermsim.git

Install geothermsim in development mode (this requires pip >= 21.1):

pip install --editable .

Once geothermsim is copied to a local directory, you can verify that it is working properly by running the notebooks.

Requirements

geothermsim was developed using Python 3.12 and is compatible with Python versions <= 3.10. In addition, the following packages are needed to run geothermsim and its examples:

• interpax (>= 0.3.8)
• jax (>= 0.6.0)
• matplotlib (>= 3.10.0),
• numpy (>= 2.2.2)
• pandas (>= 2.2.3)
• scipy (>= 1.15.1)
• SecondaryCoolantProps (>= 1.3)
• typing_extensions (>= 4.14.0)

License

geothermsim is licensed under the terms of the 3-clause BSD-license. See geothermsim license.

BSD 3-Clause License

Copyright (c) 2025, Massimo Cimmino

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.