Experimental investigations of spray flow rate and angle in enhancing the performance of PV panels by steady and pulsating water spray system

Mojtaba Nateqi,Roohollah Rafee,Mehran Rajabi Zargarabadi

doi:10.1007/s42452-021-04169-4

Abstract

In this study, a spray cooling system is experimentally investigated to increase the photovoltaic panel efficiency. Cooling of photovoltaic panels is one of the important parameters that affects the PV panel performance. In this experiment the effects of spray angle, nozzles to PV panel distance, number of nozzles, and pulsating water spray on the PV panel performance are investigated. For this purpose, an experimental setup was made. The spray angles varied from 15° to 50°. The comparison between the spray angles shows that by decreasing the spray angle to 15° increases the electrical efficiency of PV panel to 19.78% and simultaneously the average PV panel temperature decreases from 64 (for non-cooled PV) to 24 °C. Also, nozzle to PV panel distance was changed from 10 to 50 cm. The best result was obtained for the lowest distance by 25.86% increase in power output. Study of various frequency also show that due to the surface evaporation and the intensity of the radiation, increasing the water spraying frequency can increase or decrease the electrical efficiency. The On–Off water spray system results show that the maximum increase in efficiency was obtained with frequency of 0.2 Hz which it was 16.84%. Water consumption also decreased to half.

Highlights

Among renewable energy resources, solar energy is one of the most accessible resources
When the short circuit current (I sc ) increases slightly with increasing temperature, in [3] showed that the open circuit voltage ( Voc ) decreases significantly about − 2.3 mV/°C with increasing temperature. This results in a reduction of electrical power output and electrical yield of − 0.4%/°C to 0.5%/°C for mono- and multi crystalline silicon solar cells, respectively
The purpose of this study is to increase the electrical efficiency of the photovoltaic system by using the optimal water spray cooling technique

Summary

Introduction

Solar energy is one of the most accessible resources. As far as the efficiency of photovoltaic solar cells decreases with an increase in temperature [2], cooling them becomes essential to obtain better performance. When the short circuit current (I sc ) increases slightly with increasing temperature, in [3] showed that the open circuit voltage ( Voc ) decreases significantly about − 2.3 mV/°C with increasing temperature. This results in a reduction of electrical power output and electrical yield of − 0.4%/°C to 0.5%/°C for mono- and multi crystalline silicon solar cells, respectively. It is common that electrical efficiency in photovoltaic systems can be improved if module temperature is decreased

Objectives

Methods

Results