Study on technical, economic, environmental efficiency of self-consumption rooftop solar power using lithium-ion battery for households in Vietnam

Abstract

Rooftop solar power (RSP) systems are important to ensure electrical system safety and reduce investment pressure on the national power grid. The Vietnamese Government stopped the FIT price mechanism for solar power and determined that the development solution of RSP in the near future is seft-consumption. In addition, the world is currently developing many RSP projects using lithium batteries to serve self-consumption needs and use the most of excess solar power during the day. However, Vietnam does not have in-depth technical and economic analysis for grid-tied solar power projects using lithium batteries for households, so these projects receive little investment attention, especially in areas with low solar radiation. In this paper, the technical and economic efficiency of a self-consumption RSP system using lithium batteries is specifically analyzed according to different sensitivity ranges to clarify investment possibilities in 3 locations with different climate characteristics in Vietnam. The study results show that the project in Vung Tau city (Southern region) has the highest amount of solar electricity output and the net present value (NPV) is 2669$ while the projects in Hai Phong city (Northern region) and Binh Dinh (Central region) only reach $129 and $1661, respectively. The payback period of the project at the locations in Hai Phong, Binh Dinh, Vung Tau is 12.4 years, 10.7 years, and 9.9 years, respectively. Finally, the actual operating results of a typical RSP system using lithium battery present that the storage system can increase self-consumption and reduce the use of grid electricity for household loads.