Transient performance simulation and technoeconomic assessment of a smart building energy plant driven by solar energy coupled to a reversible heat pump

In developing building energy sector, employment of smart energy plants with advanced control strategies is essential to reduce energy consumption and to increase inhabitants' comfort. The solar Photovoltaic-Thermal (PVT) panels are considered as the key elements for smart building energy supply. In the present research, a combination of solar PVTs with a reversible heat pump is designed and analyzed to provide electricity, cooling, and heating energies of a case study building. The plant also includes control equipment and energy storage tank to insure smart operation under different climate conditions. The proposed plant can also be employed for a larger scale to provide energy demands of a district area. Thermal characteristics and economic features of the proposed plant are taken into account to assess its transient performance using TRNSYS software for a case study location in China with considering real climate conditions of ambient temperature and sun radiation. The produced electricity as well as cooling and heating duties are evaluated for different specifications of PVT panels and the storage tanks’ volumes. The plant performance is appraised in terms of total capital cost, CO₂ saving ratio, and the payback period. Finally a multi-objective optimization is carried out and the Pareto frontier for three objectives is represented. It has been concluded that, under optimal operation, the proposed building energy plant has a 5 year payback period with 1.93 CO₂ saving ratio and 513328 $. Also it is found that, the volume of storage tanks has a significant effect on economic indicators as well as the CO₂ saving ratio.