ThermoSysPro is an open-source component library that engineers can use to build the digital twin of their installation from an energy perspective. The goal? Thermal-hydraulic modeling of energy production and conversion plants (electricity, heat, hydrogen, etc.).

Screen capture of the video entitled "Model today and tomorrow's energy systems"

ThermoSysPro is a set of component models, developed in Modelica, that enables the realistic modeling of all types of production plants (nuclear, combined cycle, cogeneration, solar, biomass, etc.) and their interactions with their environment. By simply modeling the physical behavior of centralized production plants and new multi-energy systems, ThermoSysPro is a major vector of innovation for designing and better operating the energy systems of today and tomorrow.

The ThermosysPro library can be freely downloaded from and can be used with the OpenModelica free software. A documentation of the library is also available here:

ThermoSysPro is a single-phase and two-phase thermal-hydraulics, control-command, 0D neutronics, and electromechanics code.

Two types of applications are possible with this modeling library:

  • For design: make the best sizing choices according to environmental priorities, current regulations, physical, technological and economic constraints, etc.
  • In operation: monitor the performance of installations, quantify losses or deviations from expectations, diagnose the causes of malfunctions, evaluate the life span of components, anticipate maintenance and help to operate power plants.

For example, it has been used to carry out studies to monitor the energy performance of EDF nuclear power plants (Metroscope). ThermoSysPro has also been used, as a digital twin of a co-generation plant, to develop and optimize algorithms to control heat production in an urban network (Barkantine). Moreover, the open and scalable character of ThermoSysPro allows to quickly adapt it to the modeling of new components of the energy system, such as hydrogen or other innovative ways of producing electricity and/or heat.

Modeling is a process aiming at reproducing on a computer the behavior of an object of study, here a system (e.g., power plant, electrical network, urban energy system). This approach involves the development of a numerical model, which constitutes a mathematical and/or physical translation of the system to be studied. The model obtained is then parameterized (input data) and solved by numerical simulation to provide results on the state of the system.

The ThermoSysPro library is used in modeling and simulation environments that support the Modelica open-source language. Typically ThermoSysPro is used with the open source software OpenModelica, or the commercial software Dymola.

They use it

  • Dalkia
  • CEA
  • Naval Group
  • And also universities and high schools.

Technical characteristics

  • Open-source code under the terms of the Modelica License 2.
  • Runs on Windows or Linux operating systems.
  • Library coding in the Modelica language, compatible with the FMI interfacing standard.

For more information

> Book published by Springer Editions is available on

> website

> ThermoSysPro ITECH training Introduction to Modelica modeling of energy processes (code ARN4890)