Integration of decentralized energy systems in neighbourhoods using the energy hub approach

This paper describes a method of integrating decentralized energy systems at neighbourhood scale. The method is based on the energy hub concept, which describes and manages the relation between input and output energy flows and thus can be used to optimise energy consumption. The original energy hub concept is further developed to include decentralized and local energy technologies such as photovoltaics, biomass, or small hydro power, together with district heating systems, building and district conversion and storage technologies at neighbourhood level. Additionally, input from a building simulation tool for evaluating time-dependent buildings energy demand is included in the method. The proposed approach can be used to evaluate and size urban energy systems according to their energy-autonomy, economic and ecological performance. The advantage is that the energy supply systems and local energy storage systems can be evaluated in a combined way at district scale. The suggested method allows to lower peaks in energy demands of neighbourhoods on the electrical grid and to reduce the overall consumption. The developed method is finally applied on a case study for which future energy scenarios of different implementation scale are suggested. The area is located in a village in the mountains and contains 29 buildings. Suggested scenarios include decentralized and local renewable energy sources and district and small heating networks. Results show a variation of 52-98 tons of CO2 emissions, and an energy autonomy between 64% and 92%. In case of CO2 emissions, the best solution is given for a combination of multiple supply technologies and small networks which shows 46% lower emissions than for a scenario with only PV and biomass based systems.