Power density capacity of tidal stream turbine arrays with horizontal and vertical axis turbines

Abstract Tidal and wind energy projects almost exclusively adopt horizontal axis turbines (HATs) due to their maturity. In contrast, vertical (VATs) have received limited consideration for large-scale deployment, partly because of earlier technology readiness level. This paper analyses the power density turbine arrays comprising aligned staggered configurations with decreasing spacing HATs VATs height-to-diameter aspect ratios from one four at three real tidal sites. The VAT rotor has blades extending over a portion water depth on circular frame. Equivalent diameter is defined as $$D_0$$ D 0 = $$\sqrt{A}$$ A based projected area both HATs. three-dimensional velocity field computed using analytical wake models that capture cumulative effects. At highly energetic sites, e.g. Ramsey Sound (UK), are most suitable attaining densities beyond 100 W m $$^{-2}$$ - 2 , whilst provide higher than those sites low-to-medium velocities, Ría de Vigo (Spain) Kobe Strait (Japan). latter site, provided up 35% larger yield 14-day cycle. Our results show notably reduce effects even when deployed normalised two reaching an average capacity 40.7 compared attain 49.3 . study outlines efficiency stream other renewable resources, offshore farms, least order magnitude larger, counterbalance smaller individual performance improved array synergy limited.