THERESA - Thermal Energy Storage Test Facility

THERESA is a Thermal Energy Storage Test Facility located in the Zittau Power Plant Laboratory. It reproduces thermal power plant processes and is feasible for experimental investigations where steam or saturated water under high pressure and temperature conditions is required. THERESA supports research on several topics:     

  • components of CARNOT-Batteries (Rankine cycle)
  • integration of thermal energy storages in existing power plant systems
  • experimental investigations under realistic parameters and workloads
  • analysis of dynamic operating behaviour
  • dynamic simulations and experimental validation
  • development of automation concepts for flexible operating of combined heat and power systems with thermal storages
  • safety related investigations of plant components for industries
  • intelligent gateways (digital twin)


media water-steam-loop
max. temperature 345 °C
max. pressure 60 bar
max. steady flow rates 0.1 kg/s steam [0.5 kg/s feed-water]
saturated water cycle up to 276 °C and 60 bar
steam cycle up to 345 °C and 60 bar
universal interface
  • freely selectable steam parameters (wet / saturated / superheated steam)
  • for analysis of integration of thermal energy storages in thermal processes with different nominal power
  • for analysis and tests of specific components (e.g. heat engines or heat pumps)


Power Plant Sub-Systems

preheater 1 60 bar, 150 °C, 370 kWth, steam operated
preheater 2 60 bar, 265 °C, 255 kWth, steam operated
steam generator 60 bar, 276 °C, 200 kWel, electrically operated
super heater 60 bar, 345 °C, 60 kWel, electrically operated
heat sink pressureless, 95 °C, 17 m³
cooling circuit 16 bar, 105 °C, 780 kWth


Heat Storage

thermal battery power 240 kWth, capacity 60 kWhth, 60 bar, 265 °C, 0,6 m³
steam accumulator / generator power 180 kWth, capacity 100 kWhth, 60 bar, 276 °C, 1 m³