Research of Best Installation Angle of Off-Grid Photovoltaic Power System in Northern Shaanxi

Photovoltaic modules are used to convert solar energy to electricity in off-grid photovoltaic power system, which are usually fixed steady, and the installation angle of the system will directly affect the design of power generation capacity and economy. This research focused on the influences of installation angles of off-grid photovoltaic power system by theoretical investigation and calculation, based on the equivalent circuit model of photovoltaic modules and meteorological conditions in Northern Shaanxi. Results show that the optimal installation angles of Yulin City and Yan'an City are 40° and 30° respectively, and the minimum monthly generating capacities are 0.11kWh/Wp and 1.32kWh/Wp. Other installation angles to achieve the same performance will increase installed capacity of photovoltaic modules, and under some situations increased capacity can reach more than one times and reduce cost-effective of system greatly. Installed at the selected angle, annual generation electricity of photovoltaic modules are 1.44kWh/Wp and 1.32kWh/Wp, while some output power will be abandoned which are 0.17kWh/Wp and 0.19kWh/Wp and equal to 11.6% and 14.6% of annual generation electricity. This research will provide a theoretical reference to designing this type of renewable application in Northern Shaanxi.