A Parametric Study of a Hybrid Photovoltaic Thermal (PVT) System Coupled with a Domestic Hot Water (DHW) Storage Tank

Abstract

Photovoltaic-thermal panels are hybrid systems that combine the two types of conventional solar energy technologies (photovoltaic and thermal panels) and simultaneously generate both thermal and electrical energy in a micro-cogeneration system. Like any co-generation system, there is an optimal balance that can be achieved between the thermal and electrical energy produced. For this reason, it is important to establish the relationship and inter-connection between the two. Limited research is available on the cogeneration interaction in a PVT system, so the novelty of this article lies in the consideration of the entire energy system connected to the PVT panel, including the storage tank and the consumer demand curve, and the investigation of the thermal parametric variation. This study analyses the impact of the variation of some thermal parameters of a domestic hot water tank on the electrical efficiency of a photovoltaic-thermal panel. A model of a system of photovoltaic-thermal panels is built in a transient systems simulation program (TRNSYS) and a one-factor-at-a-time analysis is carried out for the cold-water main temperature, tank size, tank outlet flow and consumer demand curve. The results show that the variation of the outlet flow to the consumer has the highest impact on the electrical efficiency, of about 6.8%. The next highest impact factor is the size of the tank with a variation of 4.7%. Matching the profile of the consumer is also an important aspect. It was observed that the peak electrical efficiency occurs during peak consumer demand. Finally, the instantaneous variation of the thermal and electrical power of the system was analysed as a function of the temperature at the inlet of the photovoltaic-thermal panel.

Design and performance evaluation of selective energy optimization of PV/T system

“…The effect of the PV/T cell temperature versus the electrical power generated by the PV/ T cell was plotted in Figure 17 for different values of R se . Similar results are found in a parametric study of a PVT system coupled DHW on the electrical power variation as a function of the cell temperature (Barbu et al, 2020).…”

“…The results indicated that the variation of JEDT 21,5 the output flow to the customer has the most significant impact on electrical efficiency. The second-highest impact factor is the tank size with a variation (Barbu et al, 2020).…”

Control of a PVT-Heat-Pump-System Based on Reinforcement Learning–Operating Cost Reduction through Flow Rate Variation

“…Possible improvements in electrical and/or thermal yield through adjustments in cooling structures [12][13][14][15][16] or by varying the cooling fluid [17,18] have also been investigated. Some studies also addressed the impact of the flow rate on the performance of PVT systems [1], through absorber type variation [19,20], the addition of phase change materials [21], the usage of nanofluids [2] or the combination with domestic hot water tanks [22] or hydrogen production [23]. Such a variable flow rate in PVT systems shows two possible effects: first, an increased electrical yield of the PVT system and second, a controllable temperature level of the cooling fluid [24].…”

Performance Analysis and Comparison of an Experimental Hybrid PV, PVT and Solar Thermal System Installed in a Preschool in Bucharest, Romania

“…Other studies [14,15] have examined the influences of various external parameters, such as geometrical, thermo-physical, and electrical properties, climate conditions, and the thermal parameters of the installation (i.e., tank size, consumer demand curve, temperature at the inlet of the cold water main and outlet flow of the tank) on the performance of PVT system, highlighting the significant impact of the consumer demand curve.…”