Wake-Turbulence Interaction, Array Efficiency, and Levelized Cost of Energy Optimization for Floating Offshore Wind Farms in the U.S. Atlantic Outer Continental Shelf

This study investigates wake turbulence interactions, array efficiency, and LCOE optimization for floating offshore wind farms on the U.S. Atlantic Outer Continental Shelf using high-fidelity LES and farm-scale layout optimization within the context of offshore wind energy engineering and resource assessment, an area of growing scientific importance given its implications for U.S. OCS floating wind lease area layout design, BOEM LCOE-based project approval criteria, and wake steering control system specification for floating wind. Using large-eddy simulation (SOWFA v2.4) for turbine-wake interaction at 7 turbine-diameter spacing, OpenFAST structural dynamics, farm layout optimization via gradient-free optimization (CMA-ES) over 40-year ERA5 wind climate, and financial LCOE model with floating-specific CAPEX/OPEX assumptions, we examine wake velocity deficit and added turbulence from upstream turbines reducing downstream power generation 8-18% per row in regular grid layout; CMA-ES optimization repositioning turbines to exploit directional wind rose asymmetry and minimize wake overlap at predominant wind directions in 6 farm layout configurations (regular grid, staggered grid, offset row, random, wake-steering, CMA-ES optimized) x 3 turbine spacings (5D, 7D, 10D) simulated at 12 wind directions x 5 wind speed bins; LCOE compared for 500 MW nameplate capacity drawn from New England OCS sites: 41.5 N, 70.0 W (Vineyard Wind area) and 40.0 N, 73.0 W (Atlantic Shores area); ERA5 10-m wind data 1980-2022 downscaled to hub height 150 m using WRF mesoscale; water depth 90-180 m. Results indicate that CMA-ES optimized layout achieves 94.2% array efficiency vs. 84.2% regular grid at 7D spacing; LCOE $84/MWh optimized layout vs. $98/MWh regular grid (14.3% reduction); wake steering (yaw control) adds 2.4% array efficiency without layout change (p < 0.001), with 94.2% vs. 84.2% array efficiency; LCOE $84 vs. $98/MWh; wake steering +2.4% as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to offshore wind energy engineering and resource assessment and carry actionable implications for the design of programs and policies targeting U.S. OCS floating wind lease area layout design, BOEM LCOE-based project approval criteria, and wake steering control system specification for floating wind.