A Risk-Informed Approach to Performance Assurance - Structural Integrity of Offshore Wind Turbines - page 75

oil and gas facilities, marine vessels, and civil infrastructure essentially limit
their focus to life safety under rare events. The approach represented by
Figure 4-2 is a more mature method for managing risk, but one that
requires careful communication and mutual understanding among mem-
bers of the design team rather than a simple reliance on prescriptive code
provisions. Whereas the consequence of an event is often quantified in
terms of loss of life and environmental damage, the implications for the
success or failure of government policy are also a concern. Figure 4-3 illus-
trates potential policy consequences of various failure types and how
regulations can be used to mitigate this risk.

Policy Consequence: Low High

Scale of Impact: Small Large

Routine Inspection,
Maintenance and Repair
No Policy Consequence
• Lightning strike damaging
rotor blade tip
• Small vessel collision damaging
boat access landing

Fleetwide
Component Failure
Consequence: 1-2 year delay
• Monopile-transition piece grout
(serial design defect)
• Gearbox bearings
(serial manufacturing defect)

Fleetwide
Turbine Failure
Consequence: 5-10 year delay
• Structural collapse in single
first-of-a-kind project (Cape Wind)
• Structural collapse across multiple
n th-of-a-kind projects

Isolated
Turbine Failure
Low Policy Consequence
(few months delay)
• Blade strike collapsing turbine
(waterspout during grid outage)
• Ship collision collapsing turbine

Mitigate by Standards and
Certified Third-Party Reviews

FIGURE 4-3 Example risk matrix driven by policy consequences of failures.
Policy consequences represent the implications for success or failure of gov-
ernment policy—in this case, a policy of supporting the development of the
offshore wind resource. Not shown is the consequence of normal but subpar
performance—low plant availability or higher costs than projected. These
could also delay the development of the industry by making financing
and public approval more difficult to obtain. (S OURCE : Generated by the
committee.)