Abstract
The issue of efficiency decrease according to temperature increase is a pending problem in the PV market. Several active and passive technologies have been suggested but few quantitative studies on the estimation of the cooling effect have been carried out. In this study, a CFD (computational fluid dynamics) simulation model was developed to analyze a passive cooling technology using fins attached to the back of the PV module. Furthermore, a method to improve airflow at the back of the PV module by forming slits in the frame was analyzed. The simulation model reproduced the indoor test that uses a solar simulator and the cooling performance was analyzed according to the shape of the fins and the presence of slits. In the simulation results, the surface temperature and expected electrical efficiency without cooling were 62.78 °C and 13.24% respectively under nominal operating cell temperature conditions. Moreover, the temperature reduced by approximately 15.13 °C because the fins attached at the bottom of the PV module increased the heat transfer area with airflow. Thus, the electrical efficiency according to the PV module temperature was predicted as 14.39%. Furthermore, when slits were installed between the fins, they increased the airflow velocity and accelerated the formation of turbulence, thereby improving the cooling performance of the fins. The simulation results showed that the temperature could be further reduced by approximately 8.62 °C at a lower air velocity. As the fins and slits can also reduce the non-uniformity of the temperature, they are expected to supplement the efficiency and durability reduction of the PV modules caused by the hot spot phenomenon. In addition, it was shown that slits in the frame could further improve the cooling performance of the fins at a low-velocity airflow.
Highlights
Policy efforts and support to reduce carbon dioxide emissions worldwide have been recently made due to the problems of increasing energy demands and primary energy depletion [1]
The analysis model was made by means of the finite element method
Low temperatures were found in the corner because the convective heat transfer was structurally active, and turbulence was formed even though the velocity convective heat transfer was structurally active, and turbulence was formed even though the velocity was the the lowest lowest (Figures (Figures 66 and and 7)
Summary
Policy efforts and support to reduce carbon dioxide emissions worldwide have been recently made due to the problems of increasing energy demands and primary energy depletion [1]. The implementation of zero energy building (ZEB) for the energy independence of buildings is attracting attention to reduce energy demands in the building sector. The ZEB implementation requires an increase in the energy efficiency and energy production of the building itself [2]. The energy production of buildings using renewable energy facilities is an important element. Among the representative renewable energy facilities applied to buildings, PV systems are the sources of abundant energy. They are sources of renewable energy with ever increasing installation cases because they are highly applicable to buildings (Figure 1). It is Energies 2019, 12, 758; doi:10.3390/en12040758 www.mdpi.com/journal/energies
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
