Investigating the benefits of vertical staggering and optimizing turbine layout*

The growing population is placing increased stress on both energy and land resources making strategic wind farm development a necessity. Power output optimization requires understanding wake effects caused by preceding turbines within a wind farm. Alternating large and small turbines could be advantageous by mitigating wake effects and by potentially increasing the turbulent vertical kinetic energy flux, which would facilitate wake recovery. However, the use of vertical staggering is still relatively unexplored. We have improved upon a ‘top-down’ analytical model (Xie et al. Wind Energy 20, 45–62 (2017)) which is applied to periodic, vertically staggered wind farms. The model predictions are compared to large eddy simulations results. The analytical model is used to investigate the optimal spacing and profitability of vertically staggered wind farms to determine in which cases such a layout is beneficial. This work is applicable to retro-fitting present wind farms as available land area becomes increasingly limited. We discuss the effect of the main wind farm design parameters such as the turbine diameter, height, and spacing on the potential effectiveness of using vertical staggering with large and small turbines.