Technoeconomic optimisation of a residential energy system consisting of a PV-attached battery and heat pump

Abstract

This thesis assesses the technical and economic feasibility of an energy system renovation strategy for a typical 1970s multi-apartment building in Treviso (Italy) in order to increase its energy efficiency and reduce CO2 emissions. The strategy is as follows: by adding a heat pump and a battery to a solar PV system (rooftop and facade), the self-consumption of generated electricity is increased, resulting in a lower electricity bill and CO2 emissions. The goal of this thesis is to (1) to assess the self-consumption increase and (2) to determine the economic feasibility and optimum sizing of its components, particularly the battery. This was done by creating a DesignBuilder 3D building model to simulate the thermal performance of the building and by creating a MATLAB model to simulate the energy system. For PV generation with an PV-to-floor area ratio of 0.33, default self-consumption turned out to be 62%. Adding a heat pump increases the self-consumption significantly, to 87%. Further adding a 0.17kWh/m2f loor Li-ion battery increased the self consumption to 92%. All in all, the installation of a PV-attached battery and heat pump system is economically feasible and significantly increases the self-consumption of PV-generated electricity. The heat pump is most economically viable, then solar PV, while the battery barely breaks even. As battery prices dwindle, the business case for batteries is likely to gain traction in the future. By 2025, a PV-attached battery and heat pump systems have the potential to reduce EU carbon emissions significantly.