Onshore and Offshore Wind Resources and Operating Conditions in the Eastern U.S.

Abstract. A major issue in quantifying potential power generation from prospective wind energy sites is the lack of observations from heights relevant to modern wind turbines, particularly for offshore where tip heights are projected to increase beyond 250 m. We present analyses of uniquely detailed datasets from LiDAR (Light Detection And Ranging) deployments in New York State and on two buoys in the adjacent New York bight to examine the relative power generation potential and power quality at these on- and off- shore locations. Time series of 10-minute wind power production are computed from these wind speeds using the power curve from the International Energy Agency 15 MW reference wind turbine. Energy density at 150 m height at the offshore buoys is more than 40 % higher and the Weibull scale factor is 2 ms^-1 higher than at all but one of the land sites. Given the relatively close proximity of these LiDAR deployments, they share a common synoptic scale meteorology and hence the seasonal variability of wind speeds is similar with lower wind speeds in July and August. Accordingly, time series of power production from the on- and off- shore location are highly spatially correlated with the Spearman rank correlation coefficient dropping below 0.4 for separation distances of approximately 350 km, but careful planning of on- and off- shore wind farms can reduce the system-wide probability of lower wind energy power production. Analyses of the power production time series indicate AEP is almost double for the two offshore locations. Further, electrical power production quality is higher from the offshore sites that exhibit a lower amplitude of diurnal variability, plus a lower probability of wind speeds below the cut-in and of ramp events of any magnitude. Despite this and the higher resource, the estimated Levelized Cost of Energy (LCoE) is higher from the offshore sites mainly due to the higher infrastructure costs. Nonetheless, the projected LCoE is highly competitive from all sites considered.