Weather Down Time in Offshore Wind Installation Works: Assessment and Potential R&D Work Lines

Transcription

1 Alberto Avila Armella Studi di Aggiornamento sull'ingegneria Off-Shore e Marina AIOM "Tecniche e tecnologie nelle costruzioni marittime e offshore" Weather Down Time in Offshore Wind Installation Works: Assessment and Potential R&D Work Lines 1

2 Content 1. Introduction 2. Operational limits 3. Potential work lines a) WDT assessment b) Monitoring c) Improved operational limits 4. Conclusions 2

3 ScottishPower/Iberdrola Portfolio West of Duddon Sands (JV with Dong) Operating (108x3.6=389 MW) Wikinger Under construction (70x5=350 MW) East Anglia Three Development St. Brieuc Development East Anglia One CfD secured (102x7=714 MW) 3

4 1. Introduction Offshore O&G Onshore Wind Offshore Wind Key differences Technology under development. Multiple elements: long periods, repetitive. Complex O&M Logistics due to dispersion. More stable wind resource, and less turbulent. More expensive components. Challenging O&M Transmission 4

5 1. Introduction Offshore Wind founding and financial decision Process: 1. Development rights 2. Consent, feasibility studies 3. Basic engineering and tenders 4. Preferred suppliers and contractors selected 5. Final Investment Decision 6. Fabrication 7. Installation 8. Operations 9. Decommissioning 5

6 1. Introduction Uncertainties The final investment decision requires certainty (reduced margins) Weather conditions Certainty Energy yield: Long term mean regime Installation costs (due to WDT) Short term risk management, statistical analysis 6

7 2. Operational Limits Definition of offshore operations Marine operations must be engineered to guarantee: Safety of people Environment protection Integrity of elements to install Integrity of installation means 7

8 2. Operational Limits Movements Movements are the ultimately factor that determines operability. But metocean agents are used to define limits (difficult standardization). 8

9 2. Operational Limits Definition of offshore operations Offshore operations are planed contractually regulated executed based on a breakdown of activities, with limits and durations defined. 9

10 2. Operational Limits Definition of offshore operations Critical path ACTIVITIES Hs (m) Tp (s) u 10 u hub Current Visibility Duration (m/s) (m/s) (m/s) (m) (hours) 7 Jack-up and preload x x x 8 Release sea fastening crane x x 9 Tower installation x x 10 Nacelle + hub installation x x 11 Blades set installation x x 12 Crane in safe position x x 13 Jack-down, move to next position x x x 14 Positioning x x x 10

11 2. Operational Limits Sensitivity Programme Example Weather window [hr] Net time Cost of Spread 120 days 0.2 M /day Hs limit [m] Hs limit [m] Hs limit [m] % 59% % 74% % 84% % 86% Availability Total time [days] E.g. budget M 11

12 2. Operational Limits Sensitivity Budget Example: indicative day rate of installation spread: 200,000 /day Weather window [hr] Net time Cost of Spread Cost of S 120 days 0.2 M /day 0.5 Hs limit [m] Hs limit [m] Hs limit [m] Hs lim % 59% % 74% % 84% % 86% Availability Total time [days] E.g. budget M E.g. bu 12

13 3. Potential R&D Work Lines a) WDT assessment Objective of WDT assessment: Reliable information for risk management and investment decision Methods: Based on rates: for early development phases, average Based on simulation: for detailed planning, budget allocation (process simulated for historical records). 13

14 Non exceedance probability Weather Down Time in Offshore Wind Installation Works: Assessment and Potential R&D Work Lines 3. Potential R&D Work Lines a) WDT assessment 100% 50% Strategy B Strategy A Duration, Cost 14

15 3. Potential R&D Work Lines a) WDT assessment Work lines (simulation models): Improved usage and results post-processing Sensitivity analysis Presentation of results Simulation of other risks. Accuracy estimations, based on the quality of the input data. Influence of the quality of the weather forecasts expected. Customization to specific vessels. 15

16 3. Potential R&D Work Lines b) Monitoring Movement = f ( Metocean agents Characteristics of vessels and equipment Interaction between them- movements ) Work lines: Systems to monitor metocean conditions and movements during execution. Methodologies to define operational limits based on monitoring. 16

17 3. Potential R&D Work Lines b) Monitoring Subjectivity: Captain Marine Warranty Surveyor New systems need an implementation process, with the involvement of the different stakeholders (consensus, certification, experience, confidence). 17

18 3. Potential R&D Work Lines c) Improved operational limits Proprietary, for example.: Onshore Pre-commissioning. Dimensions and weight optimization. Blades installation tools. Widely applicable Equipment manufacturers. New vessels. Joint initiatives (e.g. ORE Catapult, CT OWA) 18

19 4. Conclusions There is still margin for improve WDT assessment and to optimize operations. Innovation must be inclusive for the different stakeholders. The applicability due to manufacturer-specific conditions should be taken into account. 19