Adjusting the Sails: Science and Policy Opportunities to Improve Offshore Wind Project Performance Efficiency
Abstract
The time has come for the United States to harness the headwinds facing its nascent offshore wind industry given the significant offshore wind resource potential coupled with growing coastal electricity demand. In this work, I explore interrelated atmospheric science, turbine technology, and offshore wind policy challenges with the objective to elucidate opportunities to overcome the reoccurring industry challenge of wind farm underperformance bias (WFUB). Rotor-layer wind shear and turbine available power uncertainties prior to wind farm construction may contribute to high pre-construction energy yield uncertainty, thus WFUB. To help understand this uncertainty, I introduce a novel wind profile classification algorithm to account for non-standard profiles that deviate from near power law conditions, and a method to comprehensively assess rotor-layer stability. I use these methods to characterize offshore Doppler wind lidar measurements in the Mid-Atlantic Bight and in front of a 2 MW turbine in coastal Delaware. Results demonstrate the limitation of using power law extrapolation methods to approximate average wind profile shape/shear conditions, as most wind profiles consist of atypical wind shear. Furthermore, offshore power law profiles mostly persist during unstable conditions and relatively weaker northeasterly flow from water (large fetch), whereas non-standard classified profiles are most prevalent during stable conditions and stronger southwesterly flow from land (small fetch). Interestingly, both a significant overprediction and underprediction of hub-height wind available power is possible during non-standard classified profiles, illustrating the importance of accounting for site-specific rotor-layer wind shear when predicting available power. Results from the turbine analysis corroborate offshore results, demonstrating that the highest power prediction uncertainty exists during non-standard classified wind profiles and stable conditions. Finally, given the significant role of public policy in offshore wind development, I review key science-policy obstacles impeding the reduction of wind resource and power prediction uncertainties. I provide science informed policy recommendations to better incentivize the industry to achieve the desired outcome of WFUB mitigation. Collectively, the novel methods and recommendations developed in this work support better prediction of a single turbine's power generation, which is necessary to achieve optimized project designs and ultimately improve offshore wind project performance efficiency in the burgeoning U.S. market.
- Publication:
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Ph.D. Thesis
- Pub Date:
- 2017
- Bibcode:
- 2017PhDT.......376S
- Keywords:
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- Atmospheric sciences;Public policy;Alternative Energy