On the behavior of renewable energy systems in buildings of three Saudi cities: Winter variabilities and extremes are critical

Integration of renewable energy systems emerges as a key enabler for future low-carbon electricity supply. To maintain a secure and effective supply, the design and operation of these systems must carefully account for the influence of weather variability on the availability of renewable energy resources and on energy demand. This study examines the impact of weather variability on the optimal design and operation of renewable energy systems for office buildings in Saudi Arabia. The building electricity demand is supplied by a photovoltaic/wind/battery storage system, with an additional connection to the grid. The optimization process then aims at finding the optimal capacities of the renewable energy system components, so as to strike a trade-off between life cycle cost and CO2 emissions by considering weather datasets with different levels of variability. The results show that accounting for the full weather variability, particularly the extreme weather events, leads to higher investment costs in fully renewable energy system, namely due to increased battery storage (up to 288%). Neglecting extreme events at the design stage, however, leads to a significant performance gap that could be compensated by grid integration, which adds to the overall CO2 emissions, for a negligible change in the system cost. Such extreme weather events are then associated with cloudy and high temperatures days, the impact of which drives down the photovoltaic power output and increases the demand for energy from the grid or from the storage. The study further examines the electricity price impacts on renewable energy system design and operation. With global weather variability challenges at the forefront, the paper findings draw insightful recommendations related to energy policy.