A Ducted Photovoltaic Façade Unit with Forced Convection Cooling

Abstract

This paper explores the potential of forced convection cooling in a ducted photovoltaic façade unit. Where a photovoltaic panel is backed by a 5 cm thick insulated duct at a depth of 50 cm. The potential of heat removal from the photovoltaic unit due to forced convection is investigated with a range of fan speeds from 1 m/s to 6 m/s. It is found that the ΔT between the inlet and outlet of the duct ranged from 2.6–24.6 °C. A fan speed of 4 m/s yielded the highest cooling potential by removing 550 W with a cooling efficiency of 51%. Whereas a fan speed of 6 m/s yielded the lowest mean PV cell temperature of 62.7 °C. This would improve the cell’s efficiency by 17.53%. This very experimental setup has been tested previously with natural convection cooling, which removed 529 W with a maximum efficiency of 48.98% This improves PV panel efficiency by 12.69%. The addition of heat removed and power recovered by the ducted system was 68.53% of the former (i.e., forced convection), while it was 61.67% for the latter. A 12 V DC fan with a variable speed electric circuit powered by a fraction of the PV generated power (i.e., 0.75 W) yielded better cooling that translated into nearly 19 W of further energy generation.