offshore wind engineering: constraints and opportunities

Offshore Wind Engineering:Constraints and Opportunities

Tania MoreiraOctober 2020

Topics

Projects Introduction: Key Facts01

Design: Constraints and Opportunities02

Manufacturing: Local Supply Chain Considerations 03

Construction: “Bumps on the Roads”04

Lessons Learned05Taiwan, a place of abundant offshore wind!

Offshore Wind Engineering: Constraints and OpportunitiesProjects Introduction - Key Facts: CFXD

CFXD

FEEDDetailed Design

Manufacturing

Transportation Installation

& Commissioning

Operation and Maintenance

Offshore Wind Engineering: Constraints and OpportunitiesProjects Introduction - Key Facts: ZNWF

FEEDDetailed Design

Manufacturing


& Commissioning


ZNWF

Offshore Wind Engineering: Constraints and OpportunitiesIs it complex or interesting?

Is Offshore Wind Farms Development in Taiwan Complex or Interesting?

OpportunitiesRobust Design

InterfacesLearning from

ExperienceQuality

Technology developmentAny others?

Constraints

Offshore Wind Engineering: Constraints and OpportunitiesChallenges of developing offshore wind farms in Taiwan?

FEEDDetailed Design

Manufacturing


& Commissioning


Ø Site Conditions

Ø Technology Maturity / WTG size

Ø Extreme events – earthquakes (liquefaction) & typhoons

Ø Supply Chain Challenges

Ø Construction methodology

Ø Availability/capacity of installation vessels (harsh weather conditions)

Ø Offshore / Onshore Cables Bottlenecks

Ø Any others?

Offshore Wind Engineering: Constraints and OpportunitiesSite Conditions – Seabed Mobility, the famous “bumps on the roads”

The sites are located just offshore of the Zhuoshui river which discharge huge

amounts of sediments into the area. The project conducted a detailed study of the

seabed mobility to predict the future seabed level changes in the wind farm area

before layout selection.

Offshore Wind Engineering: Constraints and OpportunitiesDesign for the unknown!

CFXD has joined the ACE JIP and it is currently working

with other developers to set up best practice guidance for

an optimized cost effective design for areas prone to

typhoon and earthquakes.

The work is scheduled to be completed in 4Q 2020 – we have the risks of performing the design whilst the JIP is

still on-going.

FEEDDetailed Design

Manufacturing


& Commissioning


Offshore Wind Engineering: Constraints and OpportunitiesSeismic – a Teamwork exercise!

FEEDDetailed Design

Manufacturing


& Commissioning


Offshore Wind Engineering: Constraints and OpportunitiesDesign for the unknown!

FEEDDetailed Design

Manufacturing


& Commissioning


ØConsensus reached with DNVGL and external advisory Professor on optimized pin pile design

based on the pile testing. Rambøll has incorporated above conclusions in the pin pile design with

resulting pin pile lengths varying.

ØPile tests have led to significantly shorter piles which optimized manufacturing and installation.

Offshore Wind Engineering: Constraints and OpportunitiesDesign for the unknown, R&D exercise!

Offshore Wind Engineering: Constraints and OpportunitiesManufacturing: Local Supply Chain Considerations

Ø Steel Grades

Ø Plates lengths (rolling capabilities)

Ø Plates thickness

Ø Section Properties – European vs. Asian

Ø Manufacturing tolerances

Ø Overall Manufacturing/Painting

Capabilities

FEEDDetailed Design

Manufacturing


& Commissioning


Offshore Wind Engineering: Constraints and OpportunitiesConstruction: “Bumps on the Roads”

FEEDDetailed Design

Manufacturing


& Commissioning


ü Early Age Cyclic (EAC): The time-depending grout

strength while hardening during installation is affected by Early Age Cycling (EAC) which may reduce the

fatigue capacity of the grouted connection and hence

only very limited relative movement is allowed during

installation (±0.5mm, total 1mm).

ü Current design does not meet DNV GL requirements

and hence tests are required for relaxation.

DNV GL Tests:

ü The test duration is approximately 7 months.

ü The box specimen to be tested is similar to the used in

the JIP for grouted connections which is representative

of a jacket connection.

ü Horizontal and Vertical testing is carried out.


FEEDDetailed Design

Manufacturing


& Commissioning


Ø Only one installation vessel can be used at a time for Changfang and Xidao for piling operation. No simultaneous piling is allowed.

Ø For Changfang Offshore Wind Farm, piling operation for a new foundation must not begin one (1) hour prior to sunset until sunrise the next day. For Xidao Offshore Wind Farm, piling operation for a new foundation must not begin two (2) hours prior to sunset until sunrise the next day.

Ø Piling noise takes over a crucial role regarding installation execution planning.


FEEDDetailed Design

Manufacturing


& Commissioning


Ø Complex crossing arrangements on the

onshore cables route.

Ø Changhua developers (CIP, Ørsted, NPI-

Yushan, CSC, and TPC renewable dept.)

agreed to coordinate common technical issues

or liaising with relevant stakeholders (TPC

IDB, and BoE) through the platform of joint

developers’ forum (JDF).

Offshore Wind Engineering: Constraints and OpportunitiesDesign for the unknown – make sure it is robust to reduce OPEX costs.

FEEDDetailed Design

Manufacturing


& Commissioning


.O&M base conceptual design

Ø The project will employ contractors to carry out the operation and maintenance tasks on the BoPassets.

Ø An advanced in-house developed numerical model has been established to determine the project accessibility.

Offshore Wind Engineering: Constraints and OpportunitiesLessons Learned – top 3

1. Invest in Research and Development, the DEVEX costs will be

paid off!

2. Adopt a positive constructive pragmatic co-operative

approach to problem solving. Bring the experts together!

3. Accept the limitations of the contractors in new development

markets. Having some empathy with the local supply chain

being relatively inexperienced and having English as a second

language and accepting that some early assistance in

preparing technical documentation may be a good investment

in the project outcome.

Thank you!

Tania Moreira, Engineering Manager

Email: [email protected]

Phone: +886 925 229 366

offshore wind engineering: constraints and opportunities

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