Performance evaluation of a stand-alone photovoltaic hybrid power system for outdoor field conditions of Thailand

This paper presents a detailed description of a stand-alone hybrid power system (SAHPS) installed in the Wang Kwang ranger station at Phu Kradueng National Park, Loei Province in central north Thailand. The SAHPS was designed to supply 203.88 kWh/day with a 24.59 kW peak load demand. The system, which generated electricity into the local mini grid, consists of 24.78 kW PV system as the renewable energy sources, the battery subsystem with 240 kWh as the energy storage, and the 48 kW diesel generator for supplying auxiliary power during the high electricity demand period. A year before the Covid-19 crisis, performance parameters based on IEA PVPS Task 13 and IEC 61724 standard are evaluated. Some performance parameters of the plant such as load profile, the yields and the performance ratio has been monitored and analyzed. The performance ratio of the PV plant varied between 33% and 70.2%. The low values of this parameter are mainly attributed to the way the battery inverter manages the energy flow. Finally, various power losses are given through an energy flow diagram.