Development and performance evaluation of solar photovoltaic module’s surface-to-rear temperature controlled valve for cooling application

Abstract

This study investigated the effectiveness of the developed solar photovoltaic (PV) module's surface-to-rear temperature-controlled solenoid valves for PV module cooling application. The cooling fluid is regulated by energizing normally closed (NC) solenoid valve with control parameters as modules rear and surface temperatures. ATmega32 microcontroller was utilized as central processing unit with two (2) LM35 as input sensors and solenoid valve as an output device. Each of 2-LM35 temperature sensors were dedicated to measure module's rear and surface temperatures respectively. The measured temperature values were coded as controlled parameters for regulating cooling fluid discharge by energizing a NC solenoid valve. The system was observed to discharge cooling fluid by energizing the solenoid valve under module's surface and rear temperature difference of less than or equal to 1.50C (Ts-Tr≤1.50C). The module's mean surface temperatures of 49.310C and 54.920C were recorded for temperature-controlled PV cooling applications and a standard solar photovoltaic/thermal (PV/T) system. The maximum recorded surface temperatures for temperature-controlled PV cooling and a standard PV/T systems were 54.00C and 57.60C respectively. The mean absorber temperatures of 45.510C and 40.870C were respectively recorded for temperature-controlled PV cooling and standard PV/T. The maximum absorber temperature recorded for temperature-controlled PV cooling and standard PV/T were 48.300C and 41.630C respectively. The solar cells temperature is reduced by 5.38% through solenoid valve temperature controlled solar module cooling application.