Project supported within the

Ocean of Tomorrow call of the

European Commission Seventh

Framework Programme

Leanwind: Needs for reliability data

O&M Workshop – IEA Task 33

23th September 2015

John Dalsgaard Sørensen Aalborg University

• Introduction - LEANWIND

• O&M objectives and O&M strategy

• Reliability implications and reliability modelling

• Risk-based O&M

• Summary - Reliability data needed

Outline

Logistic Efficiencies And Naval architecture for Wind

Installations with Novel Developments

• Beaufort Research, UCC is coordinator

• 31 partner organisations

– 52% industry partners

– Representing 11 countries;

• €14.9m total funding; €10m EC funding

• 4 year duration

– Start date: December 2013

Project summary

LEANWIND

OBJECTIVE: to provide cost reductions across the offshore wind farm

lifecycle and supply chain through the application of lean principles and

the development of state of the art technologies and tools.

Dr. Jimmy Murphy (Beaufort Research, UCC), Máire Geoghegan-Quinn (EU

Commissioner for Research, Innovation & Science), and Ørnulf Jan Rødseth

(Norwegian Marine Technology Research Institute) © Gary O'Neill

Project Summary

LEANWIND Consortium

52% Industry Partners

Aims to be industry relevant and not simply an academic project

• Construction, Deployment &

Decommissioning

• Novel Vessels & Equipment

• Operation & Maintenance

• Integrated Logistics

• System Integration

• Testing & validation of tools & technologies

• Economic & Market Assessment

LEANWIND

Work Structure

Operation and maintenance strategies

Leading work : University of Aalborg

- optimise existing O&M strategies

- develop & test condition monitoring and remote presence systems

- Use of flotels, launch and recovery, centralised offshore hubs, helicopter access, etc.

- Adapt O&G knowledge for offshore wind

LEANWIND

Work Structure

0%

20%

40%

60%

80%

100%

120%

140%

160%

2 CTV 3 CTV 2 CTV +1 SES

1 CTV +1 SES

2 SES 3 SES 1 SAV +1 CTV

1 SAV 1 MM 1 CTV +2 SES

Tota

l O&

M c

ost

s re

lati

ve t

o o

pti

mal

so

luti

on

Personnel cost

Vessel cost

Spare part cost

Lost income dueto downtime

O&M vessel fleet optimisation

Maintenance at Sheringham Shoal Offshore Wind: Image – Statkraft, www.offshorewind.biz/2014/06/06/photo-of-the-day-maintenance-at-sheringham-shoal-offshore-wind-farm/

Goal: minimize the total expected life-cycle costs

→ minimize LCOE

Initial costs: dependent on reliability level

O&M costs: dependent on O&M strategy,

availability and reliability

Failure costs: dependent on reliability

Introduction

Increasing maintenance efforts

Decreasing risk (expected failure cost)

Minimum reliability (codes, authorities ...)

Maintenance &

repair cost Optimal

strategy

Maintenance effort

Co

st,

ris

k

Expected failure

cost

Introduction

O&M objectives

• Optimize O&M strategies, procedures and scheduling for far-shore/deep water/more exposed locations.

• Reduce OPEX costs by improving condition monitoring and remote presence systems to minimize the need for on-site and corrective maintenance.

• Consider the impact of Structural Health Monitoring on life-cycle performance though minimizing O&M costs.

• Examine the influence of weather conditions, access criteria and access systems, including floating hotels, centralized offshore hubs, etc.

• Consider adaptation of Oil & Gas knowledge for the wind energy sector.

O&M Objectives – O&M strategy

• Produce a modelling tool to determine the optimal O&M

strategy of a farm given site location, distance to port,

weather window analysis etc.

• Analysis the most effective O&M strategy for different

scenarios (shore based, mothership etc.)

• Optimal maintenance strategies will be developed using

different approaches incl. risk-based techniques.

O&M strategies

• Long-term planning:

– Corrective / Preventive strategies

– Risk-based strategy

• Short-term planning

– Dynamics scheduling

– Risk-based strategy

Dependent on:

o Weather conditions

o Transport / vessels available / Logistics for spare parts,…

o Access systems

o Reliability, damage development, …

o Condition monitoring, inspections, …

Optimization of O&M strategies

Optimization of O&M strategies

Reliability implications

• Development of reliability-based design tools for off-shore

wind turbines

• Reliability, Availability, Maintainability and Safety/Security

(RAMS) methodologies for critical components

• Software tools for the simulation and optimization

Analysis of failure probabilities based on different types of information: - Observed failure rates – Classical reliability theory - Probabilistic models for failure probabilities – Structural Reliability Theory:

Limit state modeling & FORM / SORM / simulation

Mechanical / electrical

components

Structural components

Reliability modelling

Failure Rates and Downtimes (examples)

Source: ISET: 2006

Reliability modelling

• Corrective (unplanned): exchange / repair of failed

components

• Preventive (planned):

– Timetabled: inspections, and evt. repair after predefined

scheme

– Conditioned: monitor condition of system and decide next on

evt. repair based on degree of deterioration

→ risk-based using pre-posterior Bayesian decision models

Risk-based Operation & Maintenance

How can risk-based methods be used to optimal planning of

• future inspections / monitoring (time / type)

• decisions on maintenance/repair

on basis of (unknown) observations from future inspections /

monitoring

taking into account uncertainty and costs?

Risk-based Operation & Maintenance

Application of Bayesian Networks

D0 D1

FC1

Ins1

R1

RC1

D2

FC2

Ins2

R2

RC2

F1 F2

A1 A2

MU MU1 MU2

Risk-based Operation & Maintenance

Deterioration – damage accumulation:

• Deterioration processes are connected with significant uncertainty

• Observations of the actual deterioration by monitoring or inspections can

be introduced in the models and significantly improve the precision of

forecasts

•Corrosion

•Erosion

•Fatigue

•Wear

•Etc.

Risk-based Operation & Maintenance

Corrective maintenance

Data needed:

• Failure rate (and stochastic model for failure events)

• Cost model for repair

– Availability and cost of personnel, spare parts, transport possibilities

(ship, helicopter, …)

– Weather conditions

Operation & Maintenance

Condition-based / risk-based maintenance

Data needed:

• Failure rate

• Damage model, incl. uncertainty

• Cost model for repair

• Cost model for monitoring / inspection

Operation & Maintenance

• Failure rates for critical components and subsystems

• Detectability of failures

• Damage development with time

• Probabilistic models

Summary - Reliability data needed

Project supported within the

Ocean of Tomorrow call of the

European Commission Seventh

Framework Programme

Leanwind: needs for reliability data

O&M Workshop

22th September 2015

John Dalsgaard Sørensen Aalborg University

Thank You For Your Attention