Techno-Economic Analysis of a Standalone Hybrid Energy System: a Case Study in Dobrogea

This paper aims to establish the optimal scenario for an off–grid hybrid energy system (HES) composed of photovoltaic panels (PVs), wind turbines (WTs) and a diesel generator (DG) as the energy sources used for powering a residential property from Dobrogea region, in Romania. HOMER Pro software was used here to analyze the sustainability and feasibility of four system scenarios: PV/WT/DG, WT/DG, PV/DG and DG – only, based on technical, economic and environmental evaluation criteria. Simulation results showed that PV/WT/DG HES with a renewable fraction of 98.3%, containing 1.97 kW PVs, 1 kW WT, 4 kW DG, 3.03 kW power converter and six units of batteries, stood out as the optimum and most preferable system, with the minimum Cost of Energy (COE) of $0.287/kWh and Net Present Cost (NPC) of $48,879. This optimum energy system is also environmentally friendly, presenting acceptable carbon dioxide emissions of 79.9 Kg/year and reducing by 3.5 times each type of pollutant emission from PV/DG system. The battery stack status and electrical power flow for PV, WT and DG were discussed in detail via the energy balance of the PV/WT/DG system.