Solar Thermal Energy for the City of Freiberg am Neckar

Concept and simulation of solar thermal energy production including a thermal energy storage for the new Oscar-Paret-School and the surrounding quarter in the German city Freiberg am Neckar


  • Solar thermal energy
  • Thermal energy storage
  • Buildings
  • District heating
  • Energy concept
  • Energy supply


  • Study
  • Consulting


  • Public funds


09/2017 – 08/2018 (1 year)




The thermal energy supply of the new Oscar-Paret-School and the surrounding quarter in Freiberg a. N. shall be transformed to a future-oriented local heating system. Therefore, a mixture of  many diverse renewable energy sources shall be included into the district heating system which is currently not economic in decentralized systems.

Besides geothermal energy, waste heat, cogeneration of heat and power, biomass and renewable surplus electricity, there shall be integrated a solar thermal plant with an area about 2,000 m² and a thermal energy storage with about 3,000 m³ water volume.


  • German Federal Environment Foundation (DBU)
  • Transsolar Energietechnik GmbH


Steinbeis Research Institute Solites


The purpose of the subcontracting by the Transsolar Energietechnik GmbH is to support those and the city of Freiberg a. N. in performing a feasibility study funded by the German Environmental Foundation (DBU) for the redesign of a future-oriented local district heating network in Freiberg a. N. with regard to the investigation of a solar thermal system feeding into the disrict heating network and a heat storage.


During the study following aspects are analysed:

  • Determination of the expected future energy demand in the city center of Freiberg a. N. for various retrofitting scenarios.
  • Examination of various energy supply options based on thermal simulation, economic analysis and assessment of primary energy demand and CO2 emissions. In addition to the technical, energetic and ecological parameters, the local boundary conditions are included in the evaluations.
  • Detailed investigation for the determined target variant and a sensitivity analysis for the main influencing factors for the solar thermal part of the energy supply system.

Solites carries out the thermal simulations of the solar thermal system including heat storage taking into account different scenarios for the heat distribution in the district heating network and contributes the characteristics for the consideration of economic efficiency and the ecological parameters for these parts of the plant.


As a result of the feasibility study the realization of a solar thermal system with 1,300 m² and a heat storage tank with 1,000 m³ in connection with a heat pump, CHP units and gas peak load boilers was recommended to the city of Freiberg am Neckar.

This project has received funding from

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