Designs and Testing of a 10 kWp Standalone PV Prototype for Future Community Grid Adapted for Remote Area in Thailand

Abstract

This paper describes the design and testing of a 10 kWp photovoltaic system and summarizes its performance results after the first eleven months of operation. This system functions as a stand-alone power system that is used to supply electricity for isolated buildings and is designed for integration with a Micro Grid System (MGS), which is the future concept for a renewable energy-based power network system for Thailand. The system is comprised of the following components. An array with three different types of PV modules consisting amorphous thin film 3,672 W, polycrystalline solar cell 3,600 W and hybrid solar cell 2,880 W, making up a total peak power of 10.152 kW. In addition, there are three grid connected inverters (GI) of 3.5 kW each, three bi-directional inverters (BI) of 3.5 kW each and an energy storage system of 100 kWh. After the first eleven months of system operation, it was found that all the components and the overall system had worked effectively. In total, the system had generated about 14,124 kWh and the average electricity production per day was 42.8 kWh. It ranged from 33.08 kWh to 48.73 kWh. The average efficiency of amorphous thin film panel, polycrystalline panel, hybrid solar cell panel and entire photovoltaic panel system was 6.26%, 10.48%, 13.78% and 8.82% respectively. The efficiency of GI1, GI2, GI3 and entire GI ranged from 86-89%, 90-92%, 88-90% and 89-91%. While the average efficiency of BI ranged from 85-90% for charger mode and 87-92% for inverter mode. The final yield (YF) ranged from 2.54 h/d to 3.62 h/d and the performance ratio ranged from 0.57 to 0.79. From the analysis of the daily energy production, daily energy consumption and energy storage, the results seem to indicate that there was some mismatching between energy supply and demand in the system. However, this can be overcome by integrating the system to a micro grid network whereby the energy from the system can be diverted to other loads when there is a surplus and additional energy can be drawn from external sources and fed to the system when the internal supply is insufficient.