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MARINE BOARD
Chair: Michael S. Bruno, Stevens Institute of Technology, Hoboken, New Jersey
Vice Chair: Thomas M. Leschine, University of Washington, Seattle
Steven R. Barnum, Hydrographic Consultation Services, Suffolk, Virginia
Jerry A. Bridges, Virginia Port Authority, Norfolk
Mary R. Brooks, Dalhousie University, Halifax, Nova Scotia, Canada
James C. Card, Maritime Consultant, The Woodlands, Texas
Stephen M. Carmel, Maersk Line Limited, Norfolk, Virginia
Edward N. Comstock, Raytheon Company, Sudbury, Massachusetts
Stephan Toni Grilli, University of Rhode Island, Narragansett
Douglas J. Grubbs, Crescent River Port Pilots Association, Metairie, Louisiana
Frederick J. Harris, General Dynamics, San Diego, California
Judith Hill Harris, City of Portland, Maine
John R. Headland, Moffatt & Nichol Engineers, New York, New York
John M. Holmes, Port of Los Angeles, San Pedro, California
Ali Mosleh, University of Maryland, College Park
George Berryman Newton, QinetiQ North America, Marstons Mills, Massachusetts
Patrick Ernest O’Connor, BP America, Inc., Houston, Texas
Robert W. Portiss, Tulsa Port of Catoosa, Oklahoma
Peter K. Velez, Shell International Exploration and Production, Inc., Houston, Texas
John William Waggoner, HMS Global Maritime, New Albany, Indiana
TRANSPORTATION RESEARCH BOARD
2011 EXECUTIVE COMMITTEE OFFICERS
Chair: Neil J. Pedersen, Administrator, Maryland State Highway Administration,
Baltimore
Division Chair for NRC Oversight: C. Michael Walton, Ernest H. Cockrell Centennial
Chair in Engineering, University of Texas, Austin (Past Chair, 1991)
Vice Chair: Sandra Rosenbloom, Professor of Planning, University of Arizona, Tucson
Executive Director: Robert E. Skinner, Jr., Transportation Research Board
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SPECIAL REPORT 305
Structural Integrity
of Offshore Wind
Turbines
Oversight of Design,
Fabrication, and Installation
Committee on Offshore Wind Energy Turbine
Structural and Operating Safety
TRANSPORTATION RESEARCH BOARD
OF THE NATIONAL ACADEMIES
Transportation Research Board
Washington, D.C.
2011
www.TRB.org
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Transportation Research Board Special Report 305
Subscriber Categories:
Energy; bridges and other structures
Transportation Research Board publications are available by ordering individual publi-
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Office, 500 Fifth Street, NW, Washington, DC 20001 (telephone 202-334-3213; fax
202-334-2519; or e-mail TRBsales@nas.edu).
Copyright 2011 by the National Academy of Sciences. All rights reserved.
Printed in the United States of America.
NOTICE: The project that is the subject of this report was approved by the Governing
Board of the National Research Council, whose members are drawn from the councils
of the National Academy of Sciences, the National Academy of Engineering, and the
Institute of Medicine. The members of the committee responsible for the report were
chosen for their special competencies and with regard for appropriate balance.
This report has been reviewed by a group other than the authors according to the pro-
cedures approved by a Report Review Committee consisting of members of the National
Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.
This study was sponsored by the Bureau of Ocean Energy Management, Regulation,
and Enforcement, U.S. Department of the Interior.
Cover design by Debra Naylor, Naylor Design, Inc.
Cover photo: Middelgrunden offshore wind turbines in the strait of Øresund, outside
Copenhagen harbor, Denmark. (Photo by Tore Johannesen, iStockphoto.)
Typesetting by Circle Graphics.
Library of Congress Cataloging-in-Publication Data
National Research Council (U.S.). Committee on Offshore Wind Energy Turbine
Structural and Operating Safety.
Structural integrity of offshore wind turbines : oversight of design, fabrication, and
installation / Committee on Offshore Wind Energy Turbine Structural and Operating
Safety, Marine Board, Transportation Research Board of the National Academies.
p. cm. — (Transportation research board special report ; 305) 1. Offshore structures—
Design and construction—Safety measures—Government policy—United States.
2. Wind turbines—Design and construction—Safety measures—Government policy—
United States. 3. Wind power plants—United States—Safety measures. 4. Electric
power-plants, Offshore—United States—Safety measures. I. Title.
TC1665.N38 2011
621.4′53—dc22
2011004767
ISBN 978-0-309-16082-7
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Committee on Offshore Wind Energy Turbine
Structural and Operating Safety
R. Keith Michel, Herbert Engineering Corporation, Alameda,
California, Chair
Bruce R. Ellingwood, Georgia Institute of Technology, Atlanta
George M. Hagerman, Jr., Virginia Coastal Energy Research Consortium,
Virginia Beach
Jan Behrendt Ibsoe, ABS Consulting, Inc., Houston, Texas
Lance Manuel, University of Texas at Austin
Walt Musial, National Renewable Energy Laboratory, Golden, Colorado
Robert E. Sheppard, Energo Engineering, Houston, Texas
Emil Simiu, National Institute of Standards and Technology,
Gaithersburg, Maryland
Susan W. Stewart, Pennsylvania State University, State College
David J. Wisch, Chevron Energy Technology Company, Houston, Texas
Staff
Madeline G. Woodruff, Study Director
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Preface
Although many of the world’s largest wind farms are located in the
United States, these installations are entirely land based. Land-based
wind resources are plentiful but are located principally in the central
regions of the country, remote from the major population centers where
electricity demand is growing but transmission line access and capacity
are limited. There are obstacles to installing an enhanced transmission
system capable of connecting land-based wind farms to the highly pop-
ulated areas, particularly with regard to permitting.
Costs related to installation and maintenance are significantly higher
for offshore wind farms than for those located on land. However, offshore
wind farms offer a number of advantages that could offset these higher
costs. Offshore installations can be located close to coastal metropolitan
areas, reducing transmission infrastructure requirements. The intensity
of offshore wind energy is also greater, allowing the offshore wind tur-
bine to operate at greater efficiencies than a comparable land-based
installation.
There are currently offshore wind projects planned along the U.S.
East Coast, the Gulf of Mexico, and the Great Lakes. To date, most off-
shore wind farms have been located in the waters of the European and
Scandinavian nations—Germany, Denmark, and the United Kingdom
being the most important. These countries have been the leaders in both
technological and regulatory development related to offshore wind power
generation. The international standards for offshore wind turbine design
and certification established by the International Electrotechnical Com-
mission (IEC) are formally recognized in European national regulations.
Some of these national regulations also recognize the guidelines and reg-
ulations developed by classification societies.
vii
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viii Structural Integrity of Offshore Wind Turbines
In the United States, where offshore wind energy has been much less
of a focus, regulatory development has lagged. As a result, permitting of
sites in U.S. waters is proceeding without a clear set of national regula-
tions for the design, fabrication, installation, and commissioning of off-
shore wind turbines. The Minerals Management Service (MMS), which
has been renamed the Bureau of Ocean Energy Management, Regula-
tion, and Enforcement (BOEMRE), is responsible for the orderly, safe,
and environmentally responsible development of offshore renewables on
the outer continental shelf. BOEMRE requested that the Transportation
Research Board’s (TRB’s) Marine Board conduct a study to guide the
agency in the regulation and technical oversight of the nascent offshore
wind energy industry in the United States.
A study committee consisting of 10 members from academia, national
research centers, and industry was appointed by the National Research
Council (NRC). Members have expertise in structural engineering, wind
energy, regulation, third-party verification in offshore platforms and
wind turbines, and oceanography. Biographical sketches of the committee
members appear at the end of this report. The report represents the con-
sensus opinion of the committee members and presents the committee’s
findings and recommendations on the standards and practices that could
be used in oversight of U.S. offshore wind installations, the role of third-
party reviewers and BOEMRE in overseeing of the design and construc-
tion of offshore wind turbines, the necessary qualifications of third-party
reviewers, and the selection process for identifying and approving third-
party reviewers.
The committee met three times over a 5-month period. These face-
to-face meetings were supplemented by numerous conference calls. The
committee listened to presentations from a wide range of stakeholders,
including state and federal regulators, standards development organi-
zations, wind farm developers, turbine manufacturers, and research
scientists and engineers with expertise in the wind energy industry. The
committee also reviewed various studies and workshop proceedings
sponsored by BOEMRE. These resources proved invaluable as the com-
mittee discussed alternative approaches to oversight processes and for-
mulated the ideas that are presented in this report.
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Preface ix
ACKNOWLEDGMENTS
The committee acknowledges John Cushing, Lori Medley, and the other
staff members of BOEMRE who provided the committee with insight into
the responsibilities and workings of BOEMRE and into the various studies
on offshore wind energy conducted under the auspices of BOEMRE and
its predecessor, MMS. The committee also acknowledges the government
and industry representatives, listed below, who took time from their busy
schedules to present background information and their own ideas and
opinions to the committee at its meetings, and to the others who assisted
the committee by providing relevant publications and answering questions
by telephone and e-mail.
The following individuals made presentations at the first committee
meeting, June 28–29, 2010:
• John Cushing, BOEMRE, U.S. Department of the Interior;
• Malcolm Sharples, President, Offshore Risk and Technology Consult-
ing, Inc.;
• Fara Courtney, Executive Director, U.S. Offshore Wind Energy
Collaborative;
• Grover Fugate, Executive Director, Rhode Island Coastal Resources
Management Council;
• Elmer “Bud” Danenberger, MMS (retired);
• Kenneth Richardson, Vice President for Energy Projects, American
Bureau of Shipping;
• Jan Behrendt Ibsoe, Vice President for Global Renewable Energy, ABS
Consulting (committee member);
• William Holley, Technical Advisor for the U.S. National Committee of
the IEC, Technical Committee 88, Chief Consulting Engineer, Wind
Systems, GE Energy; and
• John Dunlop, Senior Project Engineer, American Wind Energy
Association.
The following individuals made presentations at the second commit-
tee meeting, August 10–11, 2010:
• Thomas Laurendine, Assistant Vice President, Liberty International
Underwriters (formerly with MMS);
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x Structural Integrity of Offshore Wind Turbines
• Jeff Shikaze, Program Manager—Renewable Energy, Canadian Stan-
dards Association (CSA);
• Richard McNitt, Business Development Manager, CSA International;
• Peter Vickery, Principal Engineer, Applied Research Associates, Inc.,
IntraRisk Division; and
• Tom McNeilan, General Manager, Fugro Atlantic (on behalf of the
Offshore Wind Development Coalition).
The report has been reviewed in draft form by individuals chosen for
their diverse perspectives and technical expertise, in accordance with
procedures approved by NRC’s Report Review Committee. The pur-
pose of this independent review is to provide candid and critical com-
ments that will assist the institution in making the published report as
sound as possible and to ensure that the report meets institutional stan-
dards for objectivity, evidence, and responsiveness to the study charge.
The review comments and draft manuscript remain confidential to pro-
tect the integrity of the deliberative process.
The committee thanks the following individuals for their review
of the report: C. P. “Sandy” Butterfield, Boulder Wind Power Inc., Boulder,
Colorado; Vice Admiral James C. Card (retired), The Woodlands, Texas;
Kent Dangtran, Dangtran OTC, LLC, Cypress, Texas; John Headland, Mof-
fatt & Nichol Engineers, New York, New York; Mary Hallisey Hunt, Strate-
gic Energy Institute, Georgia Institute of Technology, Atlanta, Georgia;
Alberto Morandi, American Global Maritime Inc., Houston, Texas; John
Niedzwecki, Zachry Department of Civil Engineering, Texas A&M
University, College Station, Texas; James Schneider, Department of Civil
and Environmental Engineering, University of Wisconsin-Madison,
Madison, Wisconsin.
Although these reviewers provided many constructive comments and
suggestions, they were not asked to endorse the committee’s findings or
recommendations, nor did they see the final draft of the report before its
release. The review was overseen by Lawrence T. Papay, PQR, LLC, and
C. Michael Walton, University of Texas at Austin. Appointed by NRC,
they were responsible for making certain that an independent exami-
nation of this report was carried out in accordance with institutional
procedures and that all review comments were carefully considered.
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xvi Structural Integrity of Offshore Wind Turbines
Composite (tower or rotor). Engineered materials made from two or
more constituent materials with significantly different physical or
chemical properties that remain separate and distinct on a macroscopic
level within the finished structure.
Condition monitoring. A process that involves a system of sensors and
monitoring equipment used to remotely monitor specific proper-
ties of a mechanical or structural system (e.g., fluid temperatures or
material strain) for the purpose of determining its ability to operate
normally.
D
Deepwater. A water depth range for offshore facilities; typically beyond
500 feet (152 m) though there is no definitive water depth range.
Design basis. The extreme conditions under which the wind turbine is
designed to operate. E.g. 50- or 100-year extreme wind and wave load-
ing events. Also includes potential fault conditions of the turbine.
Developer. The entity in a wind project that designates and arranges for
the building of an infrastructure on land or an offshore site in order
to productively exploit wind energy. Analysis of the land–sea and wind
resource characteristics are crucial in the development process.
Direct drive. A mechanism that takes the power coming from a motor
without any reductions (such as a gearbox).
Distribution system. The part of the electrical grid infrastructure that
moves electricity between local destinations either on the power gener-
ation side or the demand side (transmission systems transfer electricity
over longer distances). The wind farm electric power distribution sys-
tem consists of each turbine’s power electronics, the turbine step-up
transformer and distribution wires, the electric service platform (ESP),
cables to shore, and the shore-based interconnection system.
Downwind turbine. Refers to a horizontal axis wind turbine in which
the hub and blades point away from the wind direction, the opposite
of an upwind turbine.
Drivetrain. The transmission system of the wind turbine that converts
the low speed shaft rotational power from the rotor to electrical
power via either a gearbox and generator assembly or a direct drive
mechanism.
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Glossary xvii
E
Electric service platform (ESP). An offshore platform serving as a col-
lection and service point for a wind farm, also called a transformer
platform.
Environmental Impact Statement (EIS). A document required by the
National Environmental Policy Act (NEPA) for certain actions “sig-
nificantly affecting the quality of the human environment.” It is a tool
for decision making, describing the positive and negative environ-
mental effects of a proposed action and listing one or more alternative
actions that may be chosen instead of the action described in the EIS.
Exploratory leases. Acting under the authority granted to MMS through
the Energy Policy Act of 2005, the agency initiated the Interim Policy,
which allows for exploratory leases in November 2007 in advance of
the final regulatory framework in order to jumpstart the review and
potential authorization of the renewable energy development process.
The limited leases authorize a term of 5 years for activities on the OCS
associated with renewable energy resource data collection and tech-
nology testing.
F
Federal waters. Refers to U.S. territorial waters regulated by the U.S. fed-
eral government, as opposed to areas regulated by state authorities.
Typically this is the region beyond 3 nautical miles from shore, with
the exception of parts of the gulf coast.
G
Gear-driven. Using a mechanical system of gears or belts and pulleys to
increase or decrease shaft speed.
Goal-based standards (also known as performance-based standards).
A hierarchical standard in which the starting point is a set of high-level
performance objectives supported by a series of minimum perfor-
mance criteria that are necessary to support this objective and, finally,
a choice of methods by which satisfaction of these criteria can be
demonstrated. These methods may be prescriptive in nature; rational
alternative means and methods are permitted, provided that their
acceptability can be verified by either analysis or tests.
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xviii Structural Integrity of Offshore Wind Turbines
Guidelines. See Box 3.1.
Gravity base (or gravity-based) foundation. A type of foundation that
relies on mass and a larger base dimension to provide stability and
resist overturning.
H
Helical stage. A cylindrical gear wheel that has slanted teeth that follow
the pitch surface in a helical manner.
Horizontal axis turbine. A “normal” wind turbine design, in which
the shaft is parallel to the ground and the blades are perpendicular
to the ground
Hydrokinetic. Referring to devices that extract energy from moving
water such as rivers, ocean currents, and waves.
I
Interconnection system. The electrical system of cabling, typically oper-
ating at medium voltage, that connects the turbines to one another as
well as to the facility substation.
J
Jacket. A type of offshore structure consisting of a vertical framing system
with multiple legs and a piled foundation.
Jackup rig. A floating barge fitted with supporting legs that can be
lowered to the seabed.
L
Limit states design. A method of proportioning structural members, com-
ponents, and systems such that the design strength, defined as the prod-
uct of a nominal strength and a resistance factor, equals or exceeds the
required strength under the action of factored load combinations (also
denoted load and resistance factor design, or LRFD, in the United States).
Load and resistance factor design (LRFD). See limit states design.
M
Marine spatial planning. A tool that brings together multiple users of
the ocean, including energy, industry, government, conservation, and
recreation, to make informed and coordinated decisions about how
to use marine resources sustainably.
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Glossary xix
Memorandum of understanding (MOU). A document that defines an
agreement between two governmental agencies regarding how they will
interact in an area of shared oversight. For example, there is an MOU
between the former MMS and the Federal Energy Regulatory Com-
mission (FERC) that clarifies the roles each organization has in the
oversight of energy projects in the OCS.
Monopole. A turbine foundation structure composed of a large steel
tube driven into the seabed.
Multi-pile. See jacket.
N
Nacelle. The portion of a wind turbine that sits atop the tower protect-
ing the mechanical and electrical components (i.e., the drivetrain,
controller, and brake) from the elements.
O
Outer Continental Shelf (OCS). Refers to all submerged lands, its
subsoil, and seabed that belong to the United States and are lying
seaward and outside of the states’ jurisdiction, the latter defined as
the “lands beneath navigable waters” in Title 43, Chapter 29, Sub-
chapter I, Section 1301 of the U.S. code, The United States OCS has
been divided into four leasing regions: Gulf of Mexico, Atlantic,
Pacific, and Alaska.
P
Performance-based design. A design approach that identifies an
appropriate structural system and design parameters based on the
desired levels of performance (or performance targets) of the facil-
ity of which the structure is part; often used in seismic and blast-
resistant design.
Pitch. The angle between the edge of the blade and the plane of the
blade’s rotation. Blades are turned, or pitched, out of the wind to con-
trol the rotor speed.
Planetary stage. An outer gear that revolves about a central sun gear of
an epicyclic train.
Power electronics. The application of solid-state electronics for the con-
trol and conversion of electric power.
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xx Structural Integrity of Offshore Wind Turbines
Prescriptive. A regulatory environment in which particular activities and
schedules and parameters are prescribed a priori rather than derived
from performance targets.
Prevailing wind. The predominant direction from which the wind
blows.
Production tax credit (PTC). A federal incentive program that is designed
to help level the playing field of energy production where other forms
of energy are subsidized. At the time of press, the PTC is currently
offered to wind projects in service by December 31, 2012, over the first
10 years of operation, at a value of 2.2 cents/kWh (which increases
with inflation).
Project certification. A process to verify that the wind turbine and its
support structures meet the site-specific conditions. Use of a type-
certified wind turbine is a prerequisite.
R
Recommended practices. A type of standard or guideline developed by
a standards-development body.
Regulations. See Box 3.1.
Return period. The average interval of time between recurrences of
an event such as an earthquake or storm of a certain size or intensity,
used in risk analysis. A storm of a given intensity that has a return
period of 10 years would have a 1-in-10 probability of being exceeded
(in intensity) in any given year.
Risk-informed basis. An integrated decision paradigm in which tradi-
tional deterministic engineering evaluations are supported by insights
derived from probabilistic risk assessment (PRA) methods that take
into account uncertainties due to randomness, modeling, and com-
pleteness. Decisions may be based on both qualitative and quantita-
tive factors and consider traditional engineering information and the
risk significance of the decision.
Rotor. A complete system of blades that supplies all the force driving a
wind generator. The rotor has three blades manufactured from
fiberglass-reinforced epoxy, mounted on a hub. The blades are
pitch-regulated to continually control their angle to the wind and are
designed to optimize energy production and to generate minimal noise.
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Glossary xxi
S
SCADA (supervisory control and data acquisition). The wind farm
monitoring system that allows the owner or the turbine manufacturer,
or both, to be notified of faults or alarms, remotely control turbines,
and review operational data.
Scour. The effect of ocean waves and currents displacing seabed material
around the base of fixed structures
Shallow water. A water depth range for offshore facilities; typically
less than 200 feet (61 m), although there is no definitive water depth
range.
Siting. The process of determining a suitable location for a wind project
development.
Standards. See Box 3.1.
State waters. U.S. territorial waters regulated by state authority’s gov-
ernment, as opposed to areas regulated by the federal government,
typically within 3 nautical miles of shore.
Stationkeeping (nautical). Maintaining a fixed position in the water rel-
ative to other vessels or to a stationary object or given location.
Step-up transformer. Equipment designed to increase the voltage of an
electric power system.
Substation. A part of an electric system in which transformers are used
to step up or step down the voltage in utility power lines for transition
between long-distance transmission and local production or distri-
bution lines.
Switchgear. A device within an electric system used to control the flow
of electricity from one part of the system to another.
T
Transformer. An electrical device used to transfer power from one cir-
cuit to another using magnetic induction, usually to step voltage up
or down.
Transition piece. The connector between the foundation and the tower,
e.g., fitted around the section of the monopole that protrudes above
the waterline.
Tripod. An offshore jacket structure with three legs.
Turbine spacing. The distance between wind turbines within an array.
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xxii Structural Integrity of Offshore Wind Turbines
Turbine-to-turbine interference. The aerodynamic losses experienced
in a wind turbine array as the upstream turbines affect the energy cap-
ture of the turbines downstream within the array.
Type certification. Obtained by the wind turbine manufacturer (from
an independent body) to demonstrate that a wind turbine generator
system or installation (facility) meets specified standards for key ele-
ments such as identification and labeling, design, power performance,
noise emissions, and structural integrity.
U
Upwind turbine. A horizontal axis wind turbine in which the hub and
blades are in front of the tower in the direction of the incoming wind
(the opposite of a downwind turbine). Yaw control is required to main-
tain the upwind orientation.
V
Verification. See Box 1.3.
W
Wind farm. A set of wind turbines or one or more turbines, when con-
sidered together with the rest of the equipment involved in transfer-
ring electricity from the turbines to shore.
Wind resource. The average wind speed and direction at a range of
heights on a site; required to determine the viability of a wind turbine.
Wind shear. Changes in wind velocity with elevation.
Wind turbine generator. A rotating machine that produces electricity
from the wind.
Working stress design. A method of design in which structures or mem-
bers are proportioned for prescribed working loads at stresses that are
well below their ultimate values. The allowable stresses are determined
by applying safety factors to the ultimate values.
Y
Yaw. To rotate around a vertical axis, such a turbine tower. The yaw
drive is used to keep an upwind turbine rotor facing into the wind as
the wind direction changes.
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Contents
Executive Summary 1
1 Introduction 5
Study Charge and Scope 10
Committee Approach 12
Organization of the Report 14
2 Offshore Wind Technology and Status 17
Wind Technology 17
Status of Offshore Wind Installations 28
Offshore Wind Energy for the United States 32
3 Standards and Practices 38
Interactions Between Nonstructural Failures and
Wind Turbine Structural Integrity 38
International Electrotechnical Commission 41
API Standards 45
IEC and API Differences 46
ISO Standards 48
Classification Society Guidelines 49
Det Norske Veritas 49
Germanischer Lloyd 50
American Bureau of Shipping 51
German Standards and Project Certification Scheme 52
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Ongoing Standards Development and Related Research:
National and International 53
Areas of Limited Experience and Major Deficiencies
in Standards 56
Findings for Task I: Chapter 3 58
4 A Risk-Informed Approach to Performance Assurance 62
Risks to Human Life and the Environment Posed
by Structural Failure of Offshore Facilities 63
Regulatory Options and Policy Considerations 66
Seeking the Right Regulatory Balance 68
Regulatory Evolution in the Oil and Gas, Marine,
and Civil Infrastructure Industries 68
Transition from Prescriptive to
Performance-Based Regulations 76
Risk Mitigation Through Performance-Based Engineering 77
Alternative Approaches to Regulating the U.S. Offshore
Wind Industry 80
Goal-Based Standards for Offshore Wind Turbines 82
Overview of Projected BOEMRE Role 89
Implementation: Capacity and Expertise 91
Findings for Task I: Chapter 4 92
Recommendations for Task I: Chapters 3 and 4 92
5 Role of Third-Party Oversight and Certified
Verification Agents 96
Background 96
Offshore Oil and Gas: History of Use of CVAs 97
Current BOEMRE Regulatory Proposals for Offshore
Wind Turbines and Use of CVAs 102
Scope of Reviews 102
CVAs and Goal-Based Standards 104
Summary 106
Findings and Recommendations for Task II 106
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6 Qualifications Needed by Certified Verification Agents 109
Survey of Qualifications for Other Third-Party Reviews 109
U.S. Regulations for Offshore Wind Turbine
CVA Qualifications 114
Evaluation of Accreditation Approaches 115
Offshore Wind Turbine CVA Qualifications 117
Filling the Experience Gap 121
Findings and Recommendations for Task III 123
7 Summary of Key Findings and Recommendations 127
Finding: Safety and the Environment 127
Findings and Recommendations: Standards
and Practices (Task I) 128
Findings and Recommendations: Role of the CVA (Task II) 131
Findings and Recommendations:
CVA Qualifications (Task III) 133
Findings and Recommendations: Implementation 135
Appendices
A Risk-Informed Approaches to Safety Regulation 137
B Text of Pertinent Regulations 148
Study Committee Biographical Information 160
OCR for page R27
