Investigating the Performance of a Solar PV Driven VRF System Using Cold PCM Thermal Storage

The current paper investigates the performance of a photovoltaic solar electrical-driven variable refrigerant flow unit with cold phase change material thermal storage to reach a near-zero cooling energy building. A residential villa with a total occupied area of 300m$^{2}$ in Adana - Türkiye - was taken as a case study. Using the “Design Builder” simulation program, the baseline conventional building energy model was created, and the hourly cooling energy rate year-round was computed. The various components of the mathematical model were coded using “Visual Basic”. The main purpose of this research is to determine the optimal combination between the area of the PV panels and the thermal storage volume using the thermo-economic “Hooke and Jeeves” optimization technique. Results show that 70 PV solar panels, 73 kW VRF unit, and 10.376 m3 of cold PCM thermal storage were capable of supplying cooling energy throughout the year without the usage of any auxiliary energy sources. The amount of electrical energy consumption was then reduced by up to 98%. Unfortunately, since the electricity tariff is highly subsidized in Türkiye, the feasibility study reveals that the payback period of this system is 9 years and 7 months. However, in line with the country’s energy policy tendency toward removing these subsidies and using the real production cost, the payback period turns out to be 4 years and 3 months, triggering shareholders to make further investments in similar systems.