The study will provided guidance to BOEMRE on the direction and intent of its proposed approach to overseeing the development and safe operation of offshore wind turbines.
The study will provided findings regarding:
Task 1 - Standards and Practices: The applicability and adequacy of existing standards and practices for the design, fabrication, and installation of offshore wind turbines.
This study will focus on the gaps or overlapping areas in the current regulations for worker safety in renewable energy operations on the OCS.
The research will develop and apply methodologies to create a storm event climatology that characterizes standards-based design parameters for extreme winds, waves, currents, and water levels at event return periods appropriate to the acceptable risk for safe operation and survival of the various different components of offshore wind projects, including the turbine, rotor-nacelle-assembly, the turbine support tower, turbine and tower foundation structures, and accessory platforms.
The scope of work is broken up into the following tasks:
The research focused on establishing guidance on the burial of offshore electrical cables used to transport electricity from offshore wind farms. It addressed the current state of the art and existing standards, as well as determined acceptable burial depths, separation distances for crossings, and examined sand wave effects, and concerns for seismically active areas.
The three main objectives of this project were to:
Study the governing load cases and load effects for wind turbines subjected to tropical revolving storms on the US OCS.
Review and evaluate the existing methods of calculating the breaking wave slamming loads inflicted on offshore wind turbine support structures.
Provide recommendations to support future enhancements to the relevant design criteria for offshore wind turbines. The scope of work was broken up into the following tasks:
The research will focus on the technical feasibility of floating wind turbines with respect to the strong interactions among the wind turbine rotor, control system, floating platform, and mooring/cable system, and how different loading events will impact these systems.
The research focused on how differences in seabed conditions can affect scour in the undeveloped offshore environment and how the introduction of structures and cable-installation disturbance can further modify (increase) the scour susceptibility of the seafloor.
This was accomplished via four phases:
This effort was primarily an analytical study of resonance coincidence and its impact on the structural design characteristics of offshore wind turbines. It tapped classical methods of fluid dynamics, structural dynamics, and mechanics of materials to assess methods of preventing resonance coincidence and minimizing its consequences. It also assessed the accelerated fatigue that would result from resonance coincidence, using first order estimates of the load encountered by the wind turbine. It used data and information on offshore turbines available in the open literature.
The purpose of this project was to establish a methodological framework for estimating the installation cost of offshore wind energy devices in the US OCS and providing removal cost estimates.
The scope of work was broken up into the following tasks:
Task 1. Review and synthesize the installation methods and costs of current and proposed offshore wind energy projects, internationally and domestically, using both primary and secondary data sources including interviews with project personnel;
The efforts in this project are focused specifically on analyzing the pertinent noise transmission and radiation mechanisms associated with driving large monopile foundations. Further, the project will identify specific mitigation concepts appropriate to those mechanisms and assess the potential performance of those approaches with the context of achievable engineering design.
