Evaluation of the PV design based on minimum percentage of energy saving

Abstract

In Thailand, the use of photovoltaic (PV) energy technology is growing in popularity in the industrial sector to reduce the amount of electricity drawn from the grid. Before the system is installed, the owner must make investment decisions by evaluating the production potential of the PV system. PV sizing is designed using a simplified method under energy-saving circumstances. With the aid of this technique, the engineer can easily design the PV capacity installation and specify PV sizing in the design program. As a case study, power flow assessment was applied to a wastewater treatment system in Sakon Nakhon, Thailand. The results showed that it consumed an average of 3,643 kWh of energy per day and the plant needed to save 10% of this amount of energy annually. Consequently, the optimal capacity for the system was 101 kWp, while the approximate PV sizing was 103.8 kW, depending on factory conditions. The combined energy output of the grid and the PV system was injected into the 950.86 MWh/year electric load. The entire annual energy output from the PV system was 108.24 MWh, with the energy flow from the grid being 842.62 MWh. Based on current (2023) PV market prices, the typical installation cost was THB 27.44/W, with a payback period of 5.3 years. The developed PV system should assist the wastewater treatment plant with predicted yearly energy savings of 11.4%.