Hybrid solar photovoltaic system for self-consumption Bin-Juine Huang, Po-Chien Hsu, Tai-Chuan Wang, Guang-Yu Chen, Hsu-Yu Chang, Yu-Mi Lin, Kang Li, KY Lee + New Energy Center, Department of Mechanical Engineering, + Department of Engineering Science and Ocean Engineering National Taiwan University, Taipei, Taiwan Phone: +886-2-23636576, Fax: +886-2-23640549 E-Mail: bjhuang@seed.net.tw http://me.ntu.edu.tw/~nec ABSTRACT The present study develops a hybrid solar PV system (HyPV) which generates solar energy for local self-consumption without feed into the grid. The first system HyPV-1 was designed and installed in a residential house of NTU with 4 residents to run field test under different loads and battery storage capacity. The continuous long- term test in high season shows that two air conditioners (total power consumption 300-1500W) coupled with 1.38 kWp PV module and 1.4 kWh battery pack can be completed powered by solar PV in Taipei (low solar radiation area). HyPV-1 has been run for longer than 14 months. 1. INTRODUCTION Most grid-tied solar PV systems installed today feeds all the PV-generated power into the grid to make money from high government tariff. This will cause grid transmission problems due to the unbalance of grid power sources in clear weather when solar PV is widely disseminated. It will need additional cost for improving power transmission network or shut down solar PV plants in clear weather. A decentralized solar PV system can generate solar power for self consumption and with storage device to store excess energy without feed to the grid. Most of such kind of PV system is designed in grid-tied type with a grid-tied inverter (two-way inverter) which can import electricity from grid to make up the solar PV power supply when load is large and feed excess solar power back to grid. High quality of electricity syncronize between inverter AC output and grid AC power is required strictly. Some technical regulations and qualification procedures have to be exactly followed. This causes higher cost, especially for solar home system. In the present study, we have developed the isolated-type hybrid solar PV system (HyPV). Fig.1. A storage device is integrated with the system. The load power supply is divided in two modes: Grid Mode and PV Mode, through a switch control. When solar radiation is high or load demand is low, HyPV operates in PV Mode to supply load from battery and PV modules through an one-way inverter. When solar PV power and battery storate is not enough to supply the load, HyPV is switched to Grid Mode, with all the load power is supplied by grid. There is no feed-in grid operation. 7th International Conference on PV-Hybrid and Mini-Grids, BAD Hersfeld, Germany. APRIL 10-11, 2014