Structural Integrity of Offshore Wind Turbines: Oversight of Design, Fabrication, and Installation

TRB Special Report explores the U.S. Department of the Interior's Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) approach to overseeing the development and safe operation of wind turbines on the outer continental shelf, with a focus on structural safety. The report recommends that BOEMRE develop a set of requirements that establish goals and objectives with regard to structural integrity, environmental performance, and energy generation. The committee found that the risks to human life and the environment associated with offshore wind farms are substantially lower than for other industries such as offshore oil and gas, because offshore wind farms are primarily unmanned and contain minimal quantities of hazardous substances.


The domestic industry can build on standards, guidelines, and practices developed in Europe, where the offshore wind energy is further developed, but will have to fill gaps such as the need to address wave and wind loadings encountered in hurricanes.
The report also includes findings and recommendations about the role that certified verification agents (third party evaluators) can play in reviewing packages of standards and project-specific proposals.

Contents
Executive Summary
1 Introduction
Study Charge and Scope
Committee Approach
Organization of the Report
2 Offshore Wind Technology and Status
Wind Technology
Status of Offshore Wind Installations
Offshore Wind Energy for the United States
3 Standards and Practices
Interactions Between Nonstructural Failures and Wind Turbine Structural Integrity
International Electrotechnical Commission
API Standards
IEC and API Differences
ISO Standards
Classification Society Guidelines
Det Norske Veritas
Germanischer Lloyd
American Bureau of Shipping
German Standards and Project Certification Scheme
Ongoing Standards Development and Related Research: National and International
Areas of Limited Experience and Major Deficiencies in Standards
Findings for Task I: Chapter 3
4 A Risk-Informed Approach to Performance Assurance
Risks to Human Life and the Environment Posed by Structural Failure of Offshore Facilities
Regulatory Options and Policy Considerations
Seeking the Right Regulatory Balance
Regulatory Evolution in the Oil and Gas, Marine, and Civil Infrastructure Industries
Transition from Prescriptive to Performance-Based Regulations
Risk Mitigation Through Performance-Based Engineering
Alternative Approaches to Regulating the U.S. Offshore Wind Industry
Goal-Based Standards for Offshore Wind Turbines
Overview of Projected BOEMRE Role
Implementation: Capacity and Expertise
Findings for Task I: Chapter 4
Recommendations for Task I: Chapters 3 and 4
5 Role of Third-Party Oversight and Certified
Verification Agents
Background
Offshore Oil and Gas: History of Use of CVAs
Current BOEMRE Regulatory Proposals for Offshore Wind Turbines and Use of CVAs
Scope of Reviews
CVAs and Goal-Based Standards
Summary
Findings and Recommendations for Task II
6 Qualifications Needed by Certified Verification Agents
Survey of Qualifications for Other Third-Party Reviews
U.S. Regulations for Offshore Wind Turbine CVA Qualifications
Evaluation of Accreditation Approaches
Offshore Wind Turbine CVA Qualifications
Filling the Experience Gap
Findings and Recommendations for Task III
7 Summary of Key Findings and Recommendations
Finding: Safety and the Environment
Findings and Recommendations: Standards and Practices (Task I)
Findings and Recommendations: Role of the CVA (Task II)
Findings and Recommendations: CVA Qualifications (Task III)
Findings and Recommendations: Implementation
Appendices
A Risk-Informed Approaches to Safety Regulation
B Text of Pertinent Regulations
Study Committee Biographical Information