Techno-economic and life cycle analysis of renewable energy storage systems in buildings: The effect of uncertainty

Uncertainties in the design process of renewable energy systems (RES) in zero and net-zero energy buildings pose a significant challenge. This study introduces an innovative uncertainty-based techno-economic assessment coupled with life cycle analysis (LCA) for RES. The methodology consists of three primary stages: assessing uncertainties in energy demand, performing multi-objective optimisation to determine optimal capacity and electricity usage distribution from the grid at different self-sufficiency ratios, and conducting extensive Monte Carlo-based LCA simulations to identify environmentally optimal system designs. The results reveal substantial variations in building load analysis due to uncertainties, with peak load showing a relative deviation of approximately 24 % and average load up to 75 %. 18 deterministic and 18 uncertainty-based RESs are evaluated against 1040 scenarios to confirm that uncertainty-based systems generally surpassed deterministic ones, particularly in fully renewable scenarios, achieving higher net present values and self-sufficiency ratios. Furthermore, the LCA and Monte Carlo simulations show that there are significant variations for smaller systems but more predictable environmental impacts for larger systems. Thus, this study highlights the importance of integrating uncertainties into the design and assessment of renewable energy systems in future zero energy buildings, offering insights for sustainable building design and decision-making in addressing climate change challenges.