Design of district heating networks
District heating and cooling networks are invaluable technologies to provide energy to urban areas in a cost- and environmental effective way. topotherm is an optimization suite for district heating network design, that is developed and maintained by our research group. It is a Python-based mixed-integer linear programming district heating network model that scales well into larger districts for single and multiple time steps, making it especially suited for renewable energy sources with weather-dependent behavior and variable heating loads. It has been benchmarked against multiple other open-source models [1].
topotherm features Sseveral optimization models, which share the same core but have differing capabilities and strength:
topotherm design: Network design case (that is, the peak demand case) topology and piping optimization for a single demand point of each potential consumer.
topotherm RES: developed for weather-dependent renewable energy supply and district heating operation with variable heating demands for a set of time steps.
topotherm storage: multiple time steps with daily storage included
topotherm robust: design case which is robust against the uncertainty of chosen parameters, such as demand uncertainty or variable electricity prices
topotherm nonlinear: non-linear optimization of the system for maximal precision
Additionally, topotherm supports quasi-dynamic district heating network simulations with the full thermo-hydraulic non-linear equation system to ensure the optimization outcomes are accurate.
Topotherm provides decision making support for multiple producer types and multiple possible locations with variable characteristics, including solar thermal, heat pumps, deep hydrological geothermal, waste heat recovery.
All optimization algorithms minimize the total annualized costs or maximize profits from sold heat. Optionally, different stakeholder targets, such as greenhouse gas emission refuctions can be included with custom constraints and objective functions.
Projects:
Contact:
Jerry Lambert, Amedeo Ceruti, Lennart Trentmann
References:
[1] Lambert, Jerry and Ceruti, Amedeo and Spliethoff, Hartmut, Benchmark of Mixed-Integer Linear Programming Formulations for District Heating Network Design. Energy, Volume 308, 2024, 132885, ISSN 0360-5442, https://doi.org/10.1016/j.energy.2024.132885
[2] Ceruti, Amedeo and Lambert, Jerry and Spliethoff, Hartmut, Integrating Renewable Energy and Thermal Storage in District Heating Networks: A Design Optimization Approach. Energy Conversion and Management, Volume 345, 2025, 120323, https://doi.org/10.1016/j.enconman.2025.120323
[3] Lambert, Jerry, and Hartmut Spliethoff, A two-phase nonlinear optimization method for routing and sizing district heating systems. Energy, Volume 302, 2024, 131843, https://doi.org/10.1016/j.energy.2024.131843
[4] Lambert, Jerry, Hermann Kraus, Markus Doepfert, Miaomiao He, David Gschossmann, Amedeo Ceruti, Isabell Nemeth, Oliver Brückl, Thomas Hamacher, and Hartmut Spliethoff, Assessing the techno-economic impact of district heating on electrical distribution grid reinforcements. Applied Energy, Volume 425, 2025, 100251, https://doi.org/10.1016/j.adapen.2025.100251