Prerequisites for climate neutral energy storage in district heating

Purpose and goal

The project has analyzed seasonal thermal energy storages (TES) and in relation to Göteborg´s district heating system two alternatives show the largest potential. Skanska TES, which has been evaluated with a simulation model at Chalmers, as well as a combination solution of borehole TES (BTES) and rock cavity TES (CTES), which have not yet been simulated with Chalmers model. Both solutions indicate a yield of a magnitude that makes the alternatives interesting for continued analysis and the assessment is that there exists prerequisites for finding a suitable financing solution.

Expected results and effects

Chalmers has studied the district heating system in Gothenburg with the help of a computer-based optimization model based on two scenarios, without and with seasonal thermal energy storage Skanska TES in the system. Post-modelling calculations indicate that the carbon dioxide (CO2) emissions associated with the operation of the fossil fuel-fired HOBs reduced by 85% in the scenario with TES available in Gothenburg’s district heating system. The climate load can thus decrease considerably, while the annual system cost can decrease by 25%.

Planned approach and implementation

The project has been run according to plan with joint workshops, with complementary work carried out individually or in smaller groups in between workshops. Initially, the project was organized based on a number of identified work packages, but during the course of the work, these were divided into a red thread for the feasibility study with a number of related sub-areas. With the clarification of the connection to established performance targets, it became easier to navigate the project towards the main goal of selecting a storage solution/s with the greatest potential.