Grid-connected and off-grid solar photovoltaic system

PV systems are widely operated in grid-connected and a stand-alone mode of operations. Power fluctuation is the nature phenomena in the solar PV based energy generation system. When solar PV system operates in off-grid to meet remote load demand alternate energy sources can be identified, such as hybrid grid-tied or battery storage system for stable power supply. In the grid-connected condition when solar radiation is insufficient and unable to meet load demand, the energy is accessed from grid via net meter which makes more reliability in the consumer ends. 

Power quality is a major concern, while injecting PV to the grid and mitigating the effects of load harmonics and reactive power in the distribution system is the challenging area. Off-grid solar PV system is independent of the grid and provides freedom from power quality issues and electricity billing. The excess energy can be accumulated in the battery storage units through superior control. The main research challenges in off-grid are to provide support to load when sudden changes happened in a closed network of the load.