Techno-economic feasibility assessment of energy storage system configurations for grid-connected solar PV systems for Southern Province of Sri Lanka

Abstract

The discrepancy between peak solar energy generation and peak demand necessitates energy storage projects to effectively utilize this sustainable resource. This research conducts a techno-economic feasibility assessment of two energy storage systems: Lithium-ion Battery Energy Storage System (Li-ion BESS) and Pumped Hydro Power Plant (PHPP) integrated with grid-connected Solar PV. The aim is to store solar energy during off-peak hours and release electrical energy during peak demand in the southern province of Sri Lanka. Various configurations have been proposed for integrating the two energy storage systems with grid-connected solar PV. The required solar PV capacities for storage purposes in different regions of the southern province are analyzed using HOMER Pro. Present Cost (PC), Levelized Cost of Electricity (LCOE), Net Present Value (NPV) and Payback Period (PP) are determined by considering the construction, operation, and maintenance costs of both energy storage systems along with the relevant grid-connected solar PV costs. Both energy storage mechanisms demonstrate favourable Net Present Value (NPV) and possess Internal Rates of Return (IRR) that surpass the actual discount rate. Nevertheless, the Li-ion BESS distinguishes itself with its notably superior NPV and IRR, rendering it the more appealing financial choice. The outcomes reveal a higher initial capital cost associated with grid-connected Solar PV with PHPP. In contrast, grid-connected Solar PV with Li-ion BESS exhibits the lowest LCOE in the southern province. A shorter payback period is observed with grid-connected Solar PV integrated with Li-ion BESS. These research findings offer valuable insights for the prospective implementation of large- scale solar PV and energy storage projects in Sri Lanka