Status of the ClaRa Library: Detailed Transient Simulation of Complex Energy Systems


  • Ales Vojacek
  • Johannes Brunnemann
  • Tim Hanke
  • Thomas Marx-Schubach
  • Jörg Eiden



Energy system, ClaRa library, TransiEnt library, Thernmal Separation library, Artificial Intelligence, Waste heat, Concentrating solar, Refrigeration cycle, Heat Pump


This paper presents the current state of the open-source Modelica library ClaRa, which provides its users with the capability to proficiently tackle tasks in the disciplines of thermal hydraulics, instrumentation and control pertaining to power plants and other kind of energy systems. We provide a comprehensive overview of how the library has successfully broadened its scope over the years of its development, transcending the original focus on conventional power plants to encompass renewable power plants, waste heat utilization, general process plants, refrigeration cycles, heat pumps and beyond. The new version, ClaRa 1.8.1, brings an exciting addition to the already impressive suite of features - support for the utilization of various artificial intelligence models in Modelica simulation tools. Furthermore, the authors unveil ClaRa's ambition to serve as a potential publication platform for third-party models from a steadily growing community of ClaRa users. This is underscored by several application models. Finally, we also describe the funding scheme for maintenance of open source ClaRa by an extended commercial version, ClaRaPlus.