Technical, Financial, and Environmental Feasibility Analysis of a Hybrid Diesel-Solar Power-BESS System in the Isolated Merasa Grid

Abstract

The reliance on diesel power plants (PLTD) in isolated electrical systems results in high fuel consumption, increased operational costs, and substantial greenhouse gas emissions. This study aims to evaluate the technical, financial, and environmental feasibility of integrating solar photovoltaic (PV) systems and battery energy storage into the existing PLTD-based Merasa grid in Berau Regency, East Kalimantan. Four alternative hybrid configurations—varying PV capacities from 300 to 700 kWp and battery storage capacities from 1,200 to 1,500 kWh—were modeled and simulated using HOMER Pro based on the 2025 load profile, solar radiation data, component specifications, and cost parameters. The performance of each scenario was assessed in terms of fuel consumption, renewable fraction, capacity shortage, net present cost (NPC), levelized cost of energy (LCOE), net present value (NPV), internal rate of return (IRR), payback period, and greenhouse gas (GHG) emission reductions. The results indicate that the optimal configuration consists of a 600 kWp solar PV system and a 1,500 kWh battery storage system (utilizing Gen. 1 and Gen. 5 generators), achieving annual fuel consumption of 4,847 L/year, a renewable fraction of 96.7%, zero capacity shortage, an NPC of IDR 26.64 billion, an LCOE of IDR 2,852.97/kWh, an NPV of IDR 21.34 billion, an IRR of 15.3%, a payback period of 6.17 years, and a 96.51% reduction in GHG emissions compared with the existing PLTD-only system. This configuration is recommended as the most feasible alternative based on its combined technical, financial, and environmental performance; however, final implementation should consider land availability for solar PV installation.