Characterizing the Influence of Turbulence Intensity on Energy Production at the Vineyard Wind 1 Farm

Abstract

Turbulence in the atmospheric boundary layer mitigates wake losses between turbines and is critical to power generation by wind farms. As offshore wind energy development increases in the United States, it is necessary to understand the impact turbulence intensity uncertainty has on predicting the annual energy production (AEP) of a wind farm. In numerical models used to calculate farm power, turbulence intensity is treated as a constant input, though it has variability in the physical atmosphere. Wind conditions, such as turbulence intensity, can be modeled with numerical weather prediction (NWP), or measured with in situ instruments that may not be available offshore in the exact location of interest. For the Vineyard Wind 1 offshore farm off the coast of Massachusetts, this uncertainty between data sources led to an overprediction of 4.4% by the NWP data compared to that of the in situ data. We found that assuming a median turbulence intensity, instead of the full turbulence intensity distribution, resulted in an AEP prediction difference of less than a third of a percent. While the quantitative results presented in this thesis are site-specific to the Vineyard Wind 1 farm, the results suggest that wind condition uncertainty has a significant impact on AEP uncertainty. The results motivate further in situ measurement campaigns to assess the wind conditions that offshore wind farms will encounter.