Optimisation of district heating production by utilising the storage capacity of a district heating network on the basis of weather forecasts

Seasons cause large variations in heating demand for buildings, and the heat is produced for district heating (DH) with several heat production plants. The network itself can be assimilated to a thermal energy storage unit and used effectively for peak reduction purposes. The heat storage balances the operation of the system, which allows smoother running of the entire energy production process. Short- and long-term storage enables the transition of current energy systems towards the next generation of low-temperature DH and sustainable multi-energy networks. In this study, an example district heating system with two 4 MW boilers, located in Kymenlaakso, Finland was studied. The use of DH production was optimised by charging the network via adjusting the DH supply water temperature instead of using the reserve power. The savings potential depends on the variations in heat demand at the interface where the reserve power would have to be introduced, the size of the network volume, and the increase in the DH supply water temperature. On the basis of weather forecasts with an increase in the water temperature of 15 K, the received savings potential of reserve power could have been 185 MWh and the reduction of emissions 40 tCO2 with renewable recycling-based wood fuels during the years 2018–2020 in the environmentally friendly case network