Experimental Testbed for Solar PV-Battery Hybrid System

Abstract

Indonesia has a high potential of solar energy due to its location on the equator and in this paper, experimental testbed for PV-Battery hybrid system is developed and discussed. The hybrid system is designed to supply electricity during the night time with on-grid inverters. Practical and inexpensive solar PV-Battery hybrid system was developed and tested in Tangerang area with flexible AC electric production during the daytime as well as the night time. Practical issues for hybrid system were discovered such as limited range of inverter output voltage, sensitivity of solar panel electric production to its position and shading, accurate DC current sensor, cable and component overheating, lower inverter conversion efficiency than what specification states, safety on charging Lithium-Ion battery. Conclusions from this study are that wet battery seems to store more electric energy and more robust than the free maintenance battery, battery voltage is not a good indicator for battery level of charged, solar panel electric production is sensitive to its position and clearness from the shading, measurement of cable and component temperature is needed to justify enough cable size to deliver designed electric power, enough capacity of the component and quality of connections, care need to be taken when Lithium-ion batteries are used due to possible explosion for too high charging current.