Treffer: Renewable Energy Based Systems with Heat Pumps for Supplying Heating and Cooling in Residential Buildings

An innovative configuration of an energy system for residential buildings is examined, with the use of a numerical tool that has been developed for simulating renewable energy-based systems based on geothermal and solar energy. The main components are the PV-Thermal (PVT) collectors and a multi-source heat pump supplied by heat from either the ambient air or water, with the option to include a borehole thermal energy storage (BTES) field to increase the system’s overall efficiency. In addition, there are three water tanks for short-term thermal energy storage; a main water tank for domestic hot water (DHW) production, and two buffer tanks, with one connected to the PVT, which supplies the heat pump (solar-assisted mode), and a second one that is charged by the heat pump and from which space heating/cooling is delivered to the building. The developed code in Python solves the non-linear system of equations derived by the mathematical description of these components and their connections for the temporal variations of the temperature in the tanks and the inlet/outlet of each component. The numerical tool is used for detailed investigation of the system performance over time, as well as for analysing various layouts. In the current work, focus is given on the positive effect of the BTES component in the energy system of a building in a warm climate (Athens, Greece) and in a cold one (Copenhagen, Denmark). As expected, PVT collectors contribute heat for DHW production mostly during summer in both locations, whereas during winter they mostly charge the solar buffer tank. Moreover, the improvement of COP for cooling production with BTES is especially prominent during summer in Athens, whereas the effect of the BTES becomes more important during winter in Copenhagen, where the heating demand is high. ; This work has been performed within the RES4BUILD project (Renewables for clean energy buildings in a future power system) – Horizon 2020 program, Grant Agreement no. 814865, and was presented at ECOS 2021 – The 34th ...