Offshore Met Mast Planning, Risk and Design - … · Offshore Met Mast Planning, Risk and Design 12 December 2012 2 Offshore Wind Measurements Why Measure the wind? Met Mast/ Remote

Peter Flower12 December 2012

Offshore Met Mast Planning, Risk and Design


12 December 2012

2

Offshore Wind Measurements

� Why Measure the wind?� Met Mast/ Remote Sensing � Planning � Risk � Design


12 December 2012

WHY?

�Why do you need a met mast? .’’’’’’’’’’’’’’’’’’’’’’

�Do YOU need a met mast? .

�Can I use a Lidar?

�To provide IEC compliant wind measurements / Accurate AEP

�Yes, if you want to value your future asset.

�Yes, if you don’t need IEC compliant data

3


12 December 2012

4

Wind Measurement Central to Analysis

4

Turbine Design Turbine Design Parameters

Testing and Operations

Turbine Site Suitability

Energy Assessments

Forecasting

Layout and Site Turbine

Layout and Site Selection

WIND MEASUREMENTS


12 December 2012

What Makes a Good Measurement Campaign

5

II - Schematic view

on-site measurements

IEC quality amount of data

1

2 3

ON-site measurements: Similarity of the metmast location with the wind farm location, in termsof wind climate.IEC quality of the measurements. Accurate andprecise devices are not enough. Themeasurements have to be considered as "valid" bythe banks (i.e. equivalent to a IEC-compliant metmast)Large amount of data Best practice of 2 years ofmeasurements at the primary measurementlocation.

III- Concepts definition

1

2

3

IV - Standards and good practices

Industry Practice for distances between 1…2 km to the turbines for moderately complex terrain

IEC-61400-12 Power curve measurement

DNV Remote Sensing guidelines

DE LIDAR acceptance criteria

Siting

Devices&

Mounting

I - Why do we measure the wind on-site ?

The only way to prevent the risk of bias (accurate p50)To give estimates as precise as possible (p90)

minimizeuncertainty !

1 2 3+ +=

bankable estimate and robust

business case


12 December 2012

Example of Good Measurement Practice

6

Compliant with best practice� measurements on-site, measurements close to hub heights

Not Compliant with best practice� No measurements on-site, no measurements close to hub heights

Measurement period <2yr

Measurement period >2yrs

Wind farm B

out of all 2012 good practices

Wind farm A

• 3 years of IEC met mast data at 80-100 m

• Representative location

Wind farm C

maybe be suited for early stage or some internal analysis bankable projects + robust

business case p50


12 December 2012

7

Design Basis Wind Conditions� Assessment of Wind Conditions

- DNV-OS-J101:2007- IEC 61400-1 Ed. 3:2005- IEC 61400-3 Ed. 1:2009

� Normal wind conditions are also referred to as operational conditions.

- Input to fatigue analysis- Speed, distribution, direction, shear, turbulence

� Extreme wind conditions- Input into loads analysis

� Wake and wind farm turbulence- Input into fatigue analysis

7


12 December 2012

8




12 December 2012

9

Data collection technologies

� Offshore met mast

� Fixed platform remote sensing

� Remote sensing on floating platforms

� Buoys

Photo from NBDC - NOAA


12 December 2012

10

Data collection technologies

� Onshore met mast

� Mesoscale modeling

� Satellite observations

� Scanning lidar

� Aerial measurements

Photo courtesy ScanEagle


12 December 2012

Measuring the Wind Resource

� Meteorological (Met) Towers - Typically 80-120 m tall- Sensors at multiple heights- Data logger records data onsite- Met data well understood, “bankable”

� Remote Sensing- Ocean based- Can measure up to 200 m - New in wind industry- Used as supplement to towers…for now

11


12 December 2012

What issues need to be considered?

�Offshore measurement plans need to optimize for many criteria:- Low cost- Low power requirements- Low uncertainty at measurement point- Low uncertainty across entire project- High equipment reliability- High perceived “bankability”- Low public concerns

�No single technology provides all the answers

12


12 December 2012

13




12 December 2012

Typical offshore project – case study

14


12 December 2012

Typical Project Timeline

� 2011: Start wind measurements

� 2012: Initial site characterization

� 2013: Turbine selection and project layout

� 2014: Project design certification

� 2015: Prepare for Phase 1 construction

� 2016: Construct Phase 1

� 2017: Construct Phase 2, reassess Phase 3+4



15

Project D

evelopment Tim

eline


12 December 2012

Initial step

16


12 December 2012

Fixed Sodar/Lidar CFD results

17


12 December 2012

Case Study – Fixed sodar/lidar details

18


12 December 2012

19


12 December 2012

Additional information : Floating Lidars ?

20


12 December 2012

Case study – Floating lidar

21


12 December 2012

Floating Lidar Measurement Corrections

-10

-5

0

5

10

15

20

0 60 120 180 240 300Seconds

Win

d S

peed

(m/s

), H

eave

(m),

Pitc

h (d

egre

es)

Pitch Heave Actual Wind SpeedMeasured Wind Speed Actual Avg Speed Measured Avg Speed22


12 December 2012

Met tower installation

23


12 December 2012

Case study – Tower details

24


12 December 2012

Wake impacts

25


12 December 2012

Summary

� Representative, long term measurements are essential but can be supplemented with other data

� Combination of approaches may offer best results (lowest uncertainty) at lowest costs

� Each project is unique - Guidance on equipment and collection methods is

available- Minimum requirements are clear- But measurement campaigns must be designed for

individual projects with full consideration of objectives, risk tolerances, and impacts on uncertainty

26


12 December 2012

27


� Why Measure the wind?� Met Mast/ Remote Sensing � Planning � Risk� Design


12 December 2012

Risk: Case study example

� Project 1 is planned for construction in approximately three years and will be approximately 400 MW in size. The project will be located 20 km from the coastline, in a water depth of approximately 20 m.

� Project 2 is planned for construction starting in six years. The total project size will be approximately 4 GW, constructed in four phases of 1 GW each over four years. The project will be located approximately 40 km from the coast at its closest point, in water depths between 30 m and 40 m.

28


12 December 2012

Case Study Project 1 – Configuration A

25 KM

10 KM

LAND SEA

Offshore Buoy

Onshore weather station

SITE

Hindcast(virtual mast)


12 December 2012

Case Study Project 1 – Configuration B

25 KM

10 KM

LAND SEA

Offshore Buoy


SITE


Fixed Offshore met mast


12 December 2012

Case Study Project 1 – Configuration C

25 KM

10 KM

LAND SEA

Offshore Buoy


SITE


Fixed Offshore met mast

Floating Lidar


12 December 2012

Case Study Project 1 - Results

32

Config. A11.1%

Config. B9.0%

Config. C7.2%

0,0%

2,0%

4,0%

6,0%

8,0%

10,0%

12,0%

0 1 000 000 2 000 000 3 000 000 4 000 000 5 000 000 6 000 000 7 000 000 8 000 000 9 000 000

Com

bine

d un

cert

aint

y

Cost (GBP)

Configuration A Configuration B Configuration C

Cost of measurement (GBP) 276,358 6,484,416 8,304,575

Combined uncertainty 11.1% 9.0% 7.2%

P95/P50 Ratio 67.1% 73.4% 78.8%


12 December 2012

Case Study Project 2 – Configuration A

5 KM

3 KM

LAND SEA

Offshore Buoy

Oil platform

SITE

Regional wind map (low resolution)


12 December 2012

Case Study Project 2 – Configuration B

5 KM

3 KM

LAND SEA

Offshore Buoy

Lidar on Oil platform

SITE

Regional wind map (low resolution)


12 December 2012

Case Study Project 2 – Configuration C

5 KM

3 KM

LAND SEA

Offshore Buoy


SITE

Regional wind map (low resolution) 2 x Floating Lidar


12 December 2012

Case Study Project 2 – Configuration D

5 KM

3 KM

LAND SEA

Offshore Buoy


SITEFixed Offshore met mast

2 x Floating LidarRegional wind map (low resolution)


12 December 2012

Case Study Project 2 - Results

37

Configuration A Configuration B Configuration C Configuration D

Cost of measurement (GBP) 161,858 481,716 4,096,932 10,309,190

Combined uncertainty 20.5% 14.7% 10.9% 8.9%

P95/P50 Ratio 39.2% 56.5% 67.6% 73.8%

Config A20.5%

Config. B14.7%

Config C10.9%

Config. D8.9%

0,0%

5,0%

10,0%

15,0%

20,0%

25,0%

0 2 000 000 4 000 000 6 000 000 8 000 000 10 000 000 12 000 000

Com

bine

d un

cert

aint

y

Cost (GBP)


12 December 2012

Summary/Results� Compare ROI for various technology options, including equipment

operations costs

� Align measurement (and associated cost) with project “certainty” at various stages of project development

� Uncertainty-based cost-benefit decision making that considers project specifics can help to optimise measurement campaign expenditures

38


12 December 2012

39


� Who are DNV KEMA?� Why Measure the wind?� Met Mast/ Remote Sensing � Planning� Risk � Design


12 December 2012

Offshore Met Mast Services

� Structural verification

� Instrumentation verification- Design review- Onshore survey- Offshore survey- To ensure “bankable” data

� Instrumentation specification/supply

� Data management

� Leveraging experience instrumenting and managing 500+ tall lattice masts

� Currently providing services to several Round 3 projects

� Ensuring value and acceptance

40

Keystone Engineering's 'twisted jacket‘ DNV certified


12 December 2012

Floating Lidar Verification

� Design review

� Structural verification

� Licencing

� Geotechnical Management

� Turn Key Project Management covering Tendering/Contracts/Negotiation/ Installation, Operation and Maintenance and Recovery

� Data Management/review/monitor

41


12 December 2012

Vessel Assessment and Due Diligence

� Many new vessels planned or under construction

� Vessel achievable performance is a major influence on construction schedule/cost risk

� DNV KEMA services:- Parametric modelling of capabilities and

impact on schedule/cost- Chartering and commissioning due

diligence- Evaluate new installation concepts- Commercial support

(procurement/chartering process)- Sea trials assessment/specification

42


12 December 2012

Due Diligence

43

� Project financing

� Installation vessels

� Mergers and acquisitions

� Portfolios

� Insurers


12 December 2012

Our heritage

44

Offshore electrical engineering World-renowned in shipping

Trusted onshore wind partnerGlobal offshore experts


12 December 2012

Safeguarding life, property and the environment

www.dnv.com

45


12 December 2012

46

Example projects


12 December 2012

47

Key Atmospheric Characteristics� Wind speed

- Maximum, minimum, standard deviation- Wind speed distribution

� Barometric pressure

� Temperature

� Wind direction

� Wind shear - How wind speed changes with height

� Turbulence Intensity - Fluctuation of the wind speed

� Temporal variation- Diurnal- Seasonal- Year to year

47

Air Density


12 December 2012

DNV - Offshore Wind Project Lifetime Extension

Client La Compagnie du Vent, France

Project Les Deux Côtes lifetime extension

French regulations require that offshore wind farms should be designed for a 30 year (instead of 20 year) life

Site conditions are not known in detail

Variety of options, e.g. turbine types, are considered

Obtaining wind information independently and estimating offshore resource / extremes / turbulence

Predicting life of turbines, structures, infrastructure

Recommendations for client focus

Independent technical advice

Ability to focus on most important issues

48

Challenge

DNV’s approach

Value to the client


12 December 2012

DNV - Due Diligence for Four German Offshore Wind Projects

Client Iberdrola Erneuerbare Energien GmbH

Project Trophy (2008)

Due diligence for four offshore wind projects in the German Baltic and North Sea which are at various stages of development

Tight schedule to carry out work

Review of information available in an e-room

Independent review of wind resource, site conditions, contract conditions, costing and schedule

Independent technical advice on project feasibility

49

Challenge

DNV’s approach

Value to the client


12 December 2012

DNV - Robin Rigg Installation / Commissioning Review

Client Utility company

Project Robin Rigg Offshore Wind Farm Project Certification

Multiple party installation and commissioning of wind farm

Weather and tidal related uncertainties for any activity on site

Independent assessment of installation and commissioning methods

On-site checks and identification of non-conformities

Clarification and close-out

Independent installation and commissioning review

Full project certification

50

Challenge

DNV’s approach

Value to the client


12 December 2012

Joint Industry Project “CableRisk”

Client12 European companies: Subsea power cable manufacturers / installers and wind farm developers

ProjectDevelop a Recommended Practice for whole lifecycle of subsea power cables used in renewable and inter-connector applications (2011/12)

Persisting subsea power cable problems, frequently installation related

Threat of insurance companies to withdraw from the business

No suitable guidance for many stakeholders involved

Bring together key stakeholders in the form of a Joint Industry Project (JIP)

Investigate the issues and develop industry guidance

Review guidance with further stakeholders for endorsement

Disseminate information through free DNV-RP

First comprehensive guidance document on the subject

Reassurance of wider stakeholder community

51

Challenge

DNV’s approach

Value to the client


12 December 2012

Statoil Access System Sea Trials Support

Client Statoil (indirectly Siemens)

ProjectAssist with Sea Trials of the Maxccess Wind Turbine Access System and Bayard 3 service vessel at Hywind Demo.

Determine the performance of a new wind farm service vessel and how this may be enhanced through the installation of a personnel access system.

Develop and apply trial procedures which will determine:

1. The operational performance ability of a new access system;

2. The operational performance of a new wind-farm service vessel

3. The potential combined performance of the access system and vessel.

Improved confidence in the operational capability of the vessel and its further enhancement through the installation of a compensated and dampened access system, will lead to improved turbine availability, technician safety and reduced cost.

52

Challenge

DNV’s approach

Value to the client


12 December 2012

Installation Risk Modelling

53

Documents

Offshore Met Mast Planning, Risk and Design - … · Offshore Met Mast Planning, Risk and Design 12 December 2012 2 Offshore Wind Measurements Why Measure the wind? Met Mast/ Remote