Proof and verification of the feasibility of a large solar thermal plant in combination with a seasonal storage facility for the DH-System Salzburg with the aim of decarbonizing the energy supply mix and reducing the dependence on energy imports; use of a seasonal storage facility for the integration of further heat sources such as waste heat.

Highlights and innovative elements:

• New largest solar thermal plant in Central Europe with 45,000 m2
  o Currently: Senftenberg 8,300 m2
• World’s first large seasonal storage of 65,000 m3 in a dense urban area.
  o Total heat supply: ~ 20 GWh/a
• Seasonal storage tanks in combination with absorption heat pumps are used for the integration of heat sources in addition to solar thermal energy and enable new operating and system commitment strategies.
• Combined operation with gas cogeneration and daily storage of 30,000 m³.

Implementation steps:

• Construction of a solar collector field of 45,000 m2
• Construction of a large seasonal warehouse of 65,000 m3
• Structural feeding into the DH network
• Testing of different operating modes for large storage tanks