Photovoltaic-Battery-Supercapacitor Water Pumping System and Its Reliability Under Fluctuating Environmental Conditions
Madhumita Das
Abstract
A photovoltaic water pumping system with hybrid energy storage improves system performance and reliability under highly fluctuating radiations on cloudy or partly cloudy days.The main objective of this study is to find the reliability and effectiveness of adding dual energy storage, battery and supercapacitor, in a solar water pumping system.In this study, the cumulative pump efficiency, system efficiency, and water pumping cost have been analyzed on the test system consisting of a 12 V, 9 A hr battery, 210 F supercapacitor bank, and 12 V, 14.4 W submersible centrifugal water pump with a dynamic head of 2m to estimate the optimal PV module size for the system.It is found that the rate of change of flow rate of the system per unit change in solar radiation ranges from 0.051 to 0.092 L/hr per W/m 2 .There is a considerable improvement in the change in flow rate than a direct-coupled water pumping system which proves its potential under fluctuating radiations.The cost of water pumping is found between Indian Rupees.1.51to Rs.1.59per m 3 .The PV-Battery-Supercapacitor water pumping system is recommended to be used for partly and cloudy days for agricultural applications.