Performance of an innovative configuration of three hybrid Darrieus–Savonius vertical-axis wind turbines incorporated with building water storage tanks

This paper investigates the difficulties of utilizing wind energy in urban environments, focusing on noise pollution and the scarcity of space for turbine installation. It presents an innovative approach by integrating vertical-axis wind turbines (VAWTs) with rooftop water storage tanks, using them as structural support. The study aims to enhance the energy output from a cluster of three hybrid Darrieus–Savonius VAWTs by optimizing five key factors: turbine spacing (S12 and S13), configuration angles (ϕ12 and ϕ13), and rotation direction (RD). A three-dimensional, unsteady, and incompressible flow model is developed, which is then numerically solved and validated against previous experimental data. The impact of these variables is assessed using a Taguchi orthogonal array L16 (45). The findings indicate that RD has the greatest influence on total performance, while the distance between the first and second rotors (S12) has the least effect. The optimized configuration results in a 26.06% boost in the cluster power coefficient at a shifted tip speed ratio (TSR) of 2.86 compared to the average power coefficient of the isolated rotor (Cpavg of 0.2475) at its rated TSR of 2.64, providing an effective solution for generating electricity in urban areas with restricted space. This strategy underscores the potential to efficiently use existing urban infrastructure, such as water storage tanks, to promote the adoption of renewable energy systems.