Economic analysis of solar power plant and battery energy storage: Case study of Binh Phuoc province, Vietnam

Batteries energy storage systems (BESS) are becoming a common trend worldwide supporting an increase in the power system's renewable energy (RE). Storing energy is not applied and has been in the research process in Vietnam. This study aims to evaluate the economic performance of a solar power plant (SPP) in Vietnam both before and after integrating a BESS through key metrics including the levelized cost of electricity (LCOE), net present value (NPV), and electrical productivity. Furthermore, this study incorporates sensitivity analysis to the metrics under variations in transmission line limitation (TLL), capital expenditure (CAPEX), and subsidies in this project. The results show that the solar photovoltaic (PV) system in the chosen SPP has an LCOE of 6.13 cents/kWh and an NPV of 7.52 million USD. The NPV will decrease to zero in the TLL from 22.2 MW. If this SPP is installed with a BESS of 2 MW 2 MWh, the LCOE increases to 6.38 cents/kWh, the NPV decreases to 5.5 million USD, and the levelized storage cost (LCOS) of 126.61 cents/kWh. The PV-BESS system is no longer economically efficient when the BESS reaches 12 MWh or larger. When TLL falls below 24 MW, BESS holds a significant role in improving the system's output. CAPEX's reductions of BESS have a negligible impact on LCOE, but a significant on LCOS. Investment-based incentives (IBI) starting at 7 %, or Capital-based incentives (CBI) starting at 4 cents/W can enhance the financial attractiveness of the PV-BESS system.