Optimal off-grid electricity supply for a residential complex using water-energy-economic-environmental nexus

• Designing the off-grid electricity supply for a residential complex. • Presenting detailed life cycle analysis of several different off-grid scenarios. • Combination of batteries and PV for electricity supply of a residential complex. • Using a sophisticated decision making to choose best scenario among nine. • Economic, energy, environmental, water footprint to choose best scenario. This study evaluates the performance of off-grid hybrid renewable energy systems for a residential building in Tehran, analyzing nine scenarios that combine photovoltaic (PV) panels, vanadium redox flow (VRF), lithium iron phosphate (LFP), and nickel–cadmium (Ni-Cd) batteries, with and without biodiesel generators. A multi-objective optimization framework was applied, using Genetic Algorithms alongside TOPSIS and AHP decision-making methods, considering the Water-Energy-Economic-Environmental (WEEE) Nexus. Scenario #7, which incorporates PV panels, VRF batteries, and a biodiesel generator, was identified as the optimal configuration. This system achieves a levelized cost of electricity (LCOE) of 0.16 $/kWh—95 % lower than the reference biodiesel-only scenario—while reducing carbon emissions by 6,858.35 tonnes, biodiesel consumption by 12,558.35 m 3 , and water footprint by 5,429,818 m 3 over its lifetime. The findings highlight the significant role of battery production in both the environmental and economic impacts of off-grid systems, emphasizing the need for sustainable battery manufacturing and recycling innovations. Additionally, the study underscores the potential of advanced decision-making frameworks to optimize hybrid energy systems for both economic and environmental sustainability, providing valuable insights for future off-grid electrification projects.