Multi-criteria analysis of storages integration and operation solutions into the district heating network of Aarhus – A simulation case study

Highlights: • Control strategies impact differently centralised and decentralised storages. • Short-term storages slightly improve already well performing networks. • Economic key performance indicators must be related to a specific market context. • Price optimisation based centralised storages are the best option in Aarhus DHN. This paper assesses possibilities of integration of centralised and decentralised storages in the district heating network (DHN) of Aarhus, Denmark and their operation strategy, with the objective to smooth the heat demand during peak hours (Peak-based strategy) or to reduce the operational costs of the DHN (Price-based strategy). The analysis is carried out using a dynamic plant scheduling optimisation algorithm implemented in MATLAB to simulate and optimise the network behaviour. The results show that both strategies present similar costs reduction when applied to centralised storages. With the Peak-based strategy applied to the decentralised storages, the system runs with the cheapest costs. Additionally decentralised storages lead to different network performances depending on the scenario, from −2% to +1% of CO2 emissions and primary energy consumption. In this analysis where the performances indicators are very close, the investment costs and payback time are key criteria in order to choose the most convenient storage solution.