WEST OF DUDDON SANDS AXYS FLIDAR-6M-ZEPHIR F080 PRE...

WEST OF DUDDON SANDS AXYS FLIDAR-6M-ZEPHIR F080 PRE-DEPLOYMENT VALIDATION

Validation of the AXYS

FLiDAR-6M Single ZephIR

Floating Lidar Device, S/N

F080 at West of Duddon Sands, UK AXYS Technologies Inc.

Report No.: GLGH-4257 15 13446-R-0002, Rev. B

Date: 2016-07-27

GL Garrad Hassan Deutschland GmbH

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GL Garrad Hassan Deutschland GmbH

Project name: West of Duddon Sands AXYS FLiDAR-6M-ZephIR

F080 Pre-Deployment Validation

DNV GL / GL Garrad Hassan

Deutschland GmbH

Section Offshore Germany

Brooktorkai 18

20457 Hamburg

Germany

Tel: +49 40 36149 8693

DE 118 606 038

Report title: Validation of the AXYS FLiDAR-6M Single ZephIR

Floating Lidar Device, S/N F080 at West of

Duddon Sands, UK

Customer: AXYS Technologies Inc., Sidney, Canada

Contact person: Breanne Gellatly

Date of issue: 2016-07-27

Project No.: 4257 15 13446

Report No.: GLGH-4257 15 13446-R-0002, Rev. B

Task and objective: 3rd Party Assessment of an Offshore Pre-Deployment Validation of the AXYS FLiDAR-

6M-ZephIR Floating Lidar Device, S/N F080 at West of Duddon Sands, UK

Prepared by: Verified by: Approved by:

D.Stein

Global Head of Practice Resource

Measurements

P. Schwenk

Project Engineer

Michael Lange

Head of Section Project Engineering

☐ Strictly Confidential Keywords:

LiDAR, Floating Lidar Device, Pre-deployment

Verification

☐ Private and Confidential

☐ Commercial in Confidence

☐ DNV GL only

☒ Client’s Discretion

☐ Published

Reference to part of this report which may lead to misinterpretation is not permissible.

Rev. No. Date Reason for Issue Prepared by Verified by Approved by

A

B

2016-04-05

2016-07-27

Original version (electronic only)

Minor edits

DeSte

DeSte

PaSch

PaSch

MicLan

MicLan

DNV GL – Report No. GLGH-4257 15 13446-R-0002, Rev. B – www.dnvgl.com Page 1

Table of contents

1 INTRODUCTION .............................................................................................................. 3

1.1 Clarification Note 4

2 SETUP OF THE FLIDAR 6M PRE-DEPLOYMENT VALIDATIONS ................................................ 5

2.1 Positions of Installed FLIDAR 6M and WRMM Units 5

2.2 Description of the WoDS Reference Met Mast 6

2.3 Settings and Specs of FLIDAR 6M and WRMM Units 6

3 VALIDATION RESULTS ..................................................................................................... 8

3.1 Data provision 8

3.2 Meteorological and sea state conditions during the trial 8

3.3 Accuracy 11

3.4 Summary of verification results 13

4 REMARKS AND LIMITATIONS ......................................................................................... 16

5 CONCLUSIONS ON FLIDAR-6M-ZEPHIR BUOY TECHNOLOGY IN CONTEXT OF COMMERCIAL ROADMAP ................................................................................................ 17

6 REFERENCES ................................................................................................................ 18

APPENDIX A – APPLIED KEY PERFORMANCE INDICATORS AND ACCEPTANCE CRITERIA AXYSR

FLD PRE-DEPLOYMENT VALIDATION ................................................................................ 19

APPENDIX B – CAMPAIGN METEOROLOGICAL CONDITIONS, TIME SERIES AND WS/WD CORRELATION PLOTS .................................................................................................... 21

APPENDIX C – WAVES ................................................................................................................ 25

APPENDIX D – MET MAST SKETCH ............................................................................................... 26

APPENDIX E – SYSTEM AND DATA AVAILABILITY ........................................................................... 27


List of abbreviations

Abbreviation Meaning

AC Acceptance Criterion

AXYS AXYS Technologies Inc.

GH-D GL Garrad Hassan Deutschland GmbH, part of DNV GL group

HAT Highest Astronomical Tide

FLD Floating LiDAR Device

FLiDAR 6M AXYS FLiDAR 6M Buoy (formerly known as WindSentinel Buoy)

FLiDAR-6M-

Single-ZephIR

AXYS FLiDAR 6M Buoy employing a single ZephIR 300 type Lidar

MSL Mean Sea Level

RMM Reference Met Mast

SL Actual Sea Level

LAT Lowest Astronomical Tide

KPI Key Performance Indicator

OEM Original Equipment Manufacturer

WS Wind Speed

WD Wind Direction

WoDS West-of-Duddon-Sands

WRMM West-of-Duddon-Sands Reference Met Mast


1 INTRODUCTION

AXYS Technologies Inc. (“AXYS” the “Client”) has assigned GL Garrad Hassan Deutschland GmbH (“GH-D”), part of DNV GL Group (DNV GL) on 2015-10-12, to carry out an independent assessment of an AXYS FLiDAR 6M employing a single ZephIR (“FLiDAR-6M-Single-ZephIR” or “FLiDAR 6M”) Floating Lidar Device pre-deployment validation campaign at the West of Duddon Sands offshore met mast in UK waters in the Irish Sea. As part of this campaign DNV GL has witnessed a Site Acceptance Test (SAT) of the FLiDAR 6M carried out at the port of Barrow-In-Furness (UK) prior to deployment [2]. Furthermore

DNV GL has performed a desktop study with regards to Technical Conformance Check (TCC) of the West-of-Duddon-Sands (WoDS) meteorological mast (met mast) against applicable standards like IEC-61400-12-1 [6, 7].

The pre-deployment validation of this already “Roadmap-Pre-Commercial” staged [1] Floating Lidar Device (FLD) employing a single ZephIR 300 type Lidar was performed over a period of 183 days at the West-of-Duddon-Sands (“WoDS”) Reference Meteorological Mast (“WRMM”) which was used as the

validation reference for wind data comparisons. Data evaluation was performed for specific wind data quality related Key Performance Indicators (KPIs) and Acceptance Criteria (AC) as formulated in the Roadmap towards Commercial Acceptance [2]. DNV GL has not been involved in the data collection. Data from both the FLiDAR 6M and the WRMM were provided by or through AXYS. However, DNV GL was able to verify originality of the Lidar data, as part of it was provided in the Original Equipment Manufacturers (OEM’s) raw data format.

The Campaign started September 29th, 2015 with the deployment of the FLiDAR 6M at a position 256 m

to the West of WRMM in 24 m of water depth, compare Figure 1. The campaign lasted until March 28th,

2016.

Figure 1: Positions of FLiDAR 6M Buoy and WRMM in the Irish Sea next to the offshore wind farm West of Duddon Sands.


This report is aimed at documenting the results with respect to the pre-deployment validation trial of the AXYS FLiDAR 6M with S/N F080 against the 90 m Reference Met Mast at the West of Duddon Sands offshore wind farm in UK water in the Irish Sea.

1.1 Clarification Note It is important to note that the validation approach applied for this campaign focusses on the capabilities of floating LiDAR technology (namely in this case for the FLiDAR 6M with the buoy’s S/N F080 employing

a ZephIR Lidar with the S/N Z472) measuring primary wind data, namely wind speed and wind direction. Therefore, while the FLIDAR 6M currently features additional measures the scope of this document is limited to its primary wind data measurements.

It is further understood or has been verified that the following conditions are fulfilled in this validation

context:

The WRMM layout has been checked by DNV GL for compliance with relevant industry standards and with best practice [2]. From this DNV GL considers the layout of the F1RMM acceptable to serve as a reference for FLD validations.

The West of Duddon Sands offshore reference site provides a reasonable range of representative offshore conditions with regards to wave and meteorological properties, suitable for achieving a

representative wind speed (WS) data coverage and WS bin wise completeness according to the Roadmap [1].

The ZephIR Lidar with the S/N ZP472 mounted on the FLIDAR 6M buoy has successfully been validated against an IEC compliant onshore met mast. This validation has been performed at the ZephIR OEM’s test site in Pershore, UK, see [5].

The required wind speed data coverage and bin wise completeness for data used in this validation is in accordance with the Roadmap [1] criteria.

The wind speed and wind direction comparison results yielded according to relevant Roadmap KPIs and ACs meet at least the Roadmap minimum Acceptance Criteria.

The West of Duddon Sands offshore reference site provides a reasonable range of representative offshore conditions with regards to wave and meteorological properties.

All conclusions on the capabilities of the AXYS FLIDAR 6M drawn from this WoDS pre-deployment

validation campaign are valid under sea state and meteorological conditions similar to those experienced during the campaign duration, only.


2 SETUP OF THE FLIDAR 6M PRE-DEPLOYMENT VALIDATIONS On 2015-09-22 DNV GL witnessed a Site Acceptance Test (SAT) of the AXYS FLiDAR 6M Buoy with the S/N 413006 (Hull No. 6NB00080) sitting on the pear at the port of Barrow-in-Furness, UK. The witnessing of the SAT in terms of various relevant checks of technical setup and configurations was carried out by DNV GL together with AXYS employees).

2.1 Positions of Installed FLIDAR 6M and WRMM Units Position of WoDS Reference Met Mast( WRMM), see Figure 2, right:

The location of the WRMM is some 500 m to the NW of the WoDS offshore wind farm.

The GPS position of the WRMM is Latitude 54° 0.135’ N Longitude 003° 33.382’ W

Position of the FLIDAR 6M Floating Lidar Device, see Figure 2, left:

The FLIDAR 6M is deployed at a position of Latitude 54° 0.164’ N

Longitude 003° 33.610’ W

It is moored in 24 m of water depth (MSL) and the mooring array allows a horizontal sway freedom of movement around the anchor at a watch circle radius of 73 m.

The mooring point is about 256 m to the West of WRMM. These positions were provided by AXYS from a [4].

Figure 2: Photo of FLiDAR 6M during deployment next to WRMM (with the mast in background

of the left)


2.2 Description of the WoDS Reference Met Mast The WoDS Reference Met Mast (WRMM) is located in the Irish Sea with the coordinates 54°0.135’ N 3°33.382’ W and consists in principle of a monopile foundation with transition piece, a working platform, a 3-leged lattice tower with booms for mounting of meteorological instrumentation and an electrical system including e.g. meteorological instrumentation, navigational aids, power supplies, data systems, communications and cabling.

The WRMM provides cup measurements at 6 heights, from 25 to 85 m above MSL (i.e. between 30 and 90 m above LAT), and wind vane measures at 5 levels, from 23 to 80 m MSL. The cup top mounting is realized in a “goal-post” configuration, providing 2 first class cup anemometers at 85 m MSL orientated towards 151 and 331°, relative to mast centre.

Below the top mounting all available measurement level WD and WS sensors are installed on horizontal booms pointing 331 and 151° (Boom A and B). Additionally instrumentation for temperature, pressure

and humidity is available at different heights. Appendix D provides an as-built drawing of the WRMM showing all instruments installed to the mast. Measurements were taken using Thies first class cup anemometers, Metek USA ultrasonic anemometers and Thies first class Wind Vanes. All cup anemometers have been pre-deployment calibrated at a MEASNET [8] approved facility.

2.3 Settings and Specs of FLIDAR 6M and WRMM Units

FLIDAR 6M Floating Lidar:

FLIDAR 6M S/N F080

ZephIR S/N ZP472

Height settings 25, 45, 55, 70, 85, 102, 122, 152, 182 and 202 m rel. actual sea level

WRMM:

Reference Heights 25, 45, 55, 70, 85 m above mean sea level

These specs and height settings as listed in Table 1 are confirmed from

original ZephIR product data (ZPH-files) provided by AXYS, and

during the SAT and from WRMM conformity desktop study by DNV GL [2].


Table 1: List of heights relevant for wind data comparisons between FLIDAR 6M and WRMM (green shading, targeted heights above MSL/SL

The assessment of the KPIs and their respective Acceptance Criteria regarding wind data accuracy was

performed at three height levels between 55 m and 85 m as highlighted by green shading in Table 1.

All data collected from the deployment 2015-09-28 of FLIDAR 6M until its decommissioning on 2016-03-

29 were taken into account in the overall data processing scheme, regardless of the environmental conditions.

Nominal Height

WRMM Cup Heights

(above MSL)

FLiDAR 6M

ZephIR RG Settings

(rounded to nearest m)

FLiDAR 6M

ZephIR RG Heights [m]

(above actual sea level)

25 m 25.47m RG1 = 23 m 25,35

45 m 45.47m RG2 = 43 m 45,35

55 m 55.47m RG3 = 53 m 55,35

70 m 70.47m RG4 = 68 m 70,35

85 m 85.77m RG5 = 83 m 85,35

RG6 = 100 m 102,35

RG7 = 120 m 122,35

RG8 = 150 m 152,35

RG7 = 180 m 182,35

RG8 = 200 m 202,35


3 VALIDATION RESULTS For the pre-deployment validation of AXYS’s FLIDAR 6M against the WRMM data from the employed FLD ZephIR 300 LiDAR with the serial number ZP472 and from the WRMM were provided by AXYS for a campaign period lasting from 2015-09-29 until 2016-03-28, yielding a duration of 183 days.

3.1 Data provision

The Following remarks and reservations with respect to data transfer, traceability and processing are

noted:

WRMM and FLIDAR 6M data were provided to DNV GL for the whole campaign period by AXYS, directly.

FLIDAR 6M LiDAR wind statistics were returned by the central controller unit (called WM 500) installed on the FLIDAR 6M. This unit collected the 1-sec raw data from the ZephIR 300 to calculate the 10 minute wind data statistics.

3.2 Meteorological and sea state conditions during the trial During the validation period of the FLIDAR 6M the device encountered a wide range of wind conditions facing 10 minute average wind speeds at the WRMM of up to 28,1 m/s at the lowest comparison level (55 m) and 29.8 m/s at the upper most level (85 m) – see Table 2. The air temperatures covered during the campaign at the WRMM location and on the FLIDAR 6M buoy range from +7°C to +27°C, related

time series are displayed in Appendix B.

The significant wave heights observed during the trial period at WoDS reached heights above 5 m, with experienced maximum wave heights of up to 9.4 m. Compare Appendix C for wave statistics as provided by AXYS. The wave measurements were recorded by the FLIDAR 6M under trial itself using a 30 min data acquisition and processing interval.

The WoDS offshore area has tidal difference of 10.2 m, i.e. between 33.8 m HAT and 23.8 m LAT over 28.5 m MSL. Table 2: Maximum 10 min averaged wind speeds measure at the WRMM and by the FLIDAR 6M across the total campaign period.

WS Max WRMM FliDAR

Level / [m]

55 28,05 28,10

70 28,85 28,99

85 29,78 30,02

WS [m/s]


3.3 Availability and Reliability DNV GL has reviewed KPIs and Acceptance Criteria related to system and data availability of the FLIDAR- 6M-Single-ZephIR. An overview of the findings for each KPI is displayed in Table 3 below. System availability: Table 3 below summarizes the availability assessments for Overall System Availability (OSACA) across the

complete 6 months validation campaign and the Monthly System Availabilities (MSA1M, Month 1 to Month 6). It clearly shows that the acceptance criteria for MSA1M (to exceed 90 %) and OSACA (to exceed 95 %) as given in [2] are met for all instances. Table 3: Overall System Availability and Monthly System Availabilities across 6 months of

FLIDAR- 6M-Single-ZephIR

Data availability:

No post-processing quality filters were applied to the Lidar data for this trial, so the data availabilities after system internal filtering and after post-processed quality filtering are the same. Any external filters like those based on met mast instrumentation, sector filtering or precipitation are irrelevant when assessing the reliability of the Lidar, so the filtered data availability has not been considered here.


Table 4 below shows the Overall Post-processed Data Availability (OPDACA) across the FLIDAR- 6M-Single-ZephIR verification campaign and the Monthly Post-processed Data Availability (MPDA1M) in accordance to the Roadmap [1]. The Roadmap states that the assessment of the KPIs and their Acceptance Criteria should be performed at each selected reference level, in this case at each of the three (3) met mast’s reference anemometry levels as used in this comparison and highlighted in shading.

As a result it is shown that the acceptance criteria for Data Availability to be > 85 % across the complete campaign duration and > 80 % for each month individually are exceeded at each of the three (3) reference levels.


Table 4: Overall and Monthly Post-processed data availability. Shading indicates wind value relevant comparison levels of the FLIDAR- 6M-Single-ZephIR verification.

3.4 Accuracy DNV GL has analysed the wind data against the relevant KPIs and Acceptance Criteria given in [1] and in

Appendix A which are related to the WS and WD accuracy of the FLIDAR 6M unit. The comparisons in this section are based on ten-minute average values at both the floating LiDAR unit and the WRMM. For the analysis conducted in this section, a low wind speed cut-off of 2 m/s has been applied for the wind speed comparisons and for the wind direction comparisons.

A wind direction sector filtering needed to be applied for an easterly to South-easterly sector due to a

risk of wind flow distortion from the nearby wind farm. I.e. wind speed and direction data from a 80° wide sector between 100° and 180° were omitted from the comparison analysis.

3.4.1 Data coverage requirements for accuracy assessment

In accordance with the data coverage requirements outlined in the Roadmap A, DNV GL has assessed the data coverage of the floating LiDAR system at the four measurement heights considered. This has been conducted according to the following requirements:

a) Minimum number of 40 data points required in each 1 m/s bin wide reference wind speed bin centred between 2.5 m/s and 11.5 m/s, i.e. covering a range between 2 and 12 m/s.

b) Minimum number of 40 data points required in each 2 m/s bin wide reference wind speed bin

centred on 13 m/s and 15 m/s, i.e. covering a range 12 m/s to 16 m/s.

c) Minimum number of 40 data points in each 2 m/s bin wide reference wind speed bin centred on 17 m/s and above, i.e. covering a range above 16 m/s only if such number of data is available. This is not mandatory.

For the period considered in this report, the Roadmap related WS bin wise data completeness – to include more than 40 values per bin – was achieved for all WS bins up to 26 m/s at all treated comparison heights, and up to 26 m/s, compare Table 5. Table 5: Wind speed data coverage per WS bin. Bins including at least 40 values marked in green

WS Bins / [m/s]

Bin Center 2,5 3,5 4,5 5,5 6,5 7,5 8,5 9,5 10,5 11,5 13 15 17 19 21 23 25 27 29

Level / [m] WRMM number of 10 min data entries per WS bin - AFTER filtering for data to be used for regression analysis Sum

55 722 937 1193 1424 1321 1002 943 953 1064 980 2162 2102 1459 784 422 257 45 1 0 17812

70 714 872 1121 1335 1262 901 933 849 855 982 2047 2120 1765 1114 557 358 205 34 1 18050

85 723 848 1079 1284 1275 847 914 860 832 905 2026 2061 1806 1302 655 397 265 74 8 18195


3.4.2 Wind speed accuracy

A summary of the findings for each wind-speed-related KPI is presented in Table 6. The wind speed accuracy assessment has been conducted at three (3) heights between 55 and 85 m above MSL. The slopes (Xmws) and Coefficient of Determination (R2

mws) are presented for all compared heights. It can be seen that for the data period considered here KPIs for slope at all considered heights fall will within the best practice acceptance criterion [0.98 > XMWS > 1.02] as given in [1]. With regards to the Coefficient of Determination (R2

mws) the best practice criterion [R2mws > 0.98] is passed at all heights.

Plots for WS regression results together with WS time series plots selected for a few comparison levels can be found in Appendix B.

Table 6: Overview of linear regression analysis results for wind speed comparisons between the FLiDAR 6M Buoy and the WRMM at the selected comparison levels. Colour shading indicates the compliance with the prescribed best practice or minimum KPI’s Acceptance

Criteria (see legend).

3.4.3 Wind direction accuracy:

The wind direction data comparison was conducted for the same three (3) ZephIR probing heights

between 55 and 85 m against the mast mounted wind vane at 80 m above MSL. Note, that 180° ambiguities were observed in wind directions data yielded by the ZephIR Lidar at all heights when correlated to the wind vane readings at 80 m (see Appendix B). These ambiguities were solved in a post processing using the buoy’s own wind directions provided by an external wind vane,

which was mounted to at short mast on the buoy some 4 m above the water line. The results for the wind direction comparison are presented in Table 7 where the Wind Direction Regression Slope (Mmwd), the Mean Offset (OFFmwd) and the Coefficient of Determination (R2

mwd) are presented. The KPI values for R2

mwd and for slope Mmwd from all heights fall within the best practice acceptance criteria. KPI values for OFFmwd meet the minimum criteria at all heights. Plots for WD regression results selected for a few heights can be found in Appendix C.

WS comparison slope R2 coeff. WS CUP avg WS LID avg WS diff.relative

WS diff.

Level / [m] # Xmws R2mws m/s m/s m/s

ZephIR 55 17812 0,994 0,996 11,24 11,21 -0,03 -0,3%

70 18050 0,994 0,996 11,55 11,52 -0,03 -0,3%

85 18195 0,993 0,997 11,82 11,77 -0,05 -0,5%

KPIs

Legend

KPI -AC failed

KPI -AC passed minimum

KPI -AC passed best practice


Table 7: Overview of linear regression results for WD comparisons between FLIDAR 6M and the WRMM at the selected comparison levels. Colour shading indicates compliance with prescribed best practice or minimum KPI’s Acceptance Criteria (see legend).

3.5 Summary of verification results

3.5.1 Campaign Duration

The campaign duration with exactly 6 months is considered rather long, compared to a typically

expected duration of 6 to 8 weeks. So it was easy within this duration to achieve the required data completeness in useable WS bins for data analysis and results, in order to be compliant to the Roadmap

in terms of significance of FLIDAR 6M wind data accuracy results.

3.5.2 System reliability and data availability

Monthly and campaign-overall system and data availabilities have been calculated for this 6 months

validation campaign. These yielded successful results well above the prescribed ACs (in terms of ROADMAP [1] requirements) which are given in Table 8 below. Table 8: Summary of achievement after 183 days (6 months) with regards to KPIs and Acceptance Criteria for system and data availability

KPI Definition / Rationale Acceptance Criteria across total of

five (5) months campaign duration;

OSACA Overall System Availability –

Campaign Average

≥95%

Results:

[99.2 % ] Passed

MSA1M Monthly System Availability –

Monthly average for each

of the 6 single months

≥90%

Results:

[97.6 % to 99.7 % ] Passed

WD comparison slope R2 coeff. mean diff.

KPIs

Level / [m] # Mmwd R2mwd OFFmwd

ZephIR 55 17811 1,004 0,995 6,90

70 18049 1,004 0,995 7,20

85 18195 1,002 0,995 7,38

Legend

KPI -AC failed

KPI -AC passed minimum

KPI -AC passed best practice


KPI Definition / Rationale Acceptance Criteria across total of

five (5) months campaign duration;

OPDACA Overall Post-quality-filtered

Data Availability

Campaign Average

evaluated at each of the three (3)

comparison levels

No Lidar system internal quality filters

were applied in the data analysis

≥85

Results:

ZP1: [99.2 % ] Passed @ all levels

MPDA1M Monthly Post-quality-filtered

Data Availability –

Monthly average for each

of the 6 single months

evaluated at each of the three (3)

comparison levels

No Lidar system internal quality filters

were applied in the data analysis

≥80%

Results:

[97.6 % to 99.7 % ] Passed

3.5.3 Wind Measurement Accuracy

The wind speeds of both the FLIDAR 6M and the WRMM at all comparison heights correlated very well, showing a low level of scatter and good agreement in terms of linear regression analyses. This comparison campaign indicates that the FLIDAR-6M-ZephIR is able to reproduce fixed Lidar wind speeds at a high level of accuracy. The Best Practice criteria for the KPIs “Mean Wind Speed – Slope” and “Mean Wind Speed – Coefficient of Determination” were surpassed at all treated height levels. For wind direction Best Practice criteria or Minimum criteria were passed at all comparison heights for

the KPIs “Mean Wind Direction – Slope”, “Mean Wind Direction – Coefficient of Determination” and “Mean Wind Direction – Offset” indicating the FLIDAR 6M’s capability of reproducing fixed Lidar wind directions at a high level of accuracy. The detailed results with respect to KPIs and ACs for wind speed and wind direction comparisons are

given in Table 9 below.


Table 9: Summary of achievement after 183 days (6 months) with regards to KPIs and Acceptance Criteria for the data accuracy assessment

KPI Definition / Rationale

Acceptance Criteria across total

campaign duration

Best Practice Minimum

Xmws Mean Wind Speed – Slope

Assessed for wind speed range [all above 2 m/s]

0.98 – 1.02

Results:

[0.993 to 0.994]

Passed at all

compared heights

0.97 – 1.03

R2mws Mean Wind Speed – Coefficient of

Determination


>0.98

Results:

[0.996 to 0.997]

Passed at all

compared heights

>0.97

Mmwd Mean Wind Direction – Slope


(WD filtering/clipping applied for Easterly sector from 40° to 140° due to potential wind flow deflection by land masses / islands)

0.97 – 1.03

Results:

[1.002 to 1.004]

Passed at all

compared heights

0.95 – 1.05

OFFmwd Mean Wind Direction – Offset,

in terms of the mean absolute WD

difference over the total campaign

duration

(same as for Mmwd)

< 5°

< 10°

Results:

6.9 to 7.38]

Passed at all

compared heights

R2mwd Mean Wind Direction – Coefficient

of Determination

(same as for Mmwd)

> 0.97

Results:

[0.995]

Passed at all

compared heights

> 0.95


4 REMARKS AND LIMITATIONS

The presented results have to be regarded under the following reservations and limitations:

Both data sets, (a) the one for the Reference Met Mast (WRMM) and (b) the one for the FLIDAR 6M were provided to DNV GL by AXYS, i.e. they’ve had full access to the data from the tested device and from the reference data. However, DNV GL was able to verify originality of (a) the Lidar data as part of it was provided in the Original Equipment Manufacturers (OEM’s) raw data format, and (b) that they were directly downloaded from the reference met mast owner’s (I.e.

DONG’s) FTP data server.

All conclusions on the capabilities of the FLIDAR 6M drawn from this WoDS pre-deployment

verification campaign are valid under sea states and meteorological conditions similar to those experienced during this trial, only.


5 CONCLUSIONS ON FLIDAR-6M-ZEPHIR BUOY TECHNOLOGY IN CONTEXT OF COMMERCIAL ROADMAP

An independent evaluation of the AXYS FLiDAR 6M Buoy employing a ZephIR 300 type Lidar (FLIDAR 6M

single-ZephIR, formerly known as WindSentinel) was completed by DNV GL in in assessing its reliability

and comparing its wind measurements from the buoy mounted ZephIR Lidar against data from the WoDS Reference Met Mast (WRMM) in the Irish Sea. Sufficient data in terms of WS data completeness and coverage totalling a period of exactly 6 months were collected to allow an assessment in line with the Roadmap for commercialization of Floating Lidar Devices [1].

DNV GL concludes that the AXYS FliDAR-6Msingle-ZephIR unit with the S/N F080 has demonstrated its capability to produce accurate wind speed and direction data across the range of sea states and meteorological conditions experienced in this trial. I.e. significant wave heights of > 5 m (and > 9 m for maximum wave height) were recorded by the Buoy. The Lidar wind speeds recorded at WoDS covered a range of up to 28.1 m/s at 55 m and 29.8 m/s at 85 m.

FLD Roadmap related WS bin wise data completeness was achieved for all WS bins up to 26 m/s at all treated comparison heights. The assessments of the Roadmap KPIs for the complete data set (from September 29th 2015 until March 28th 2016) show that

all FLD-Roadmap Acceptance Criteria for Overall and Monthly System Availability and Data Availability are met

all FLD-Roadmap Acceptance Criteria for wind speed data accuracy related KPIs are met at best practice level at all selected heights

all FLD-Roadmap Acceptance Criteria for wind direction related KPIs are met at least at the minimum level but mostly at the best practice level.

Finally, based on the 6 months lasting WoDS verification campaign results as reported here DNV GL draws the conclusion that the AXYS FLiDAR 6M Buoy (FLiDAR 6M) employing at least a single ZephIR 300 type Lidar (as the primary Lidar) has formally qualified for Stage 2 “pre-commercial” in the context of the OWA/CT Roadmap towards commercialization of Floating Lidar Devices [1].


6 REFERENCES

[1] Offshore Wind Accelerator Roadmap for the commercial acceptance of floating Lidar technology. The Carbon Trust, 21 November 2013.

[2] DNV GL Report GLGH-4257 15 13446-T-0001, Rev. B: “Technical Note on Port

Site Acceptance Test of WoDS AXYS FLiDAR 6M (Wind Sentinel) Buoy and Technical Conformity Check of Offshore Reference Met Mast”, issued 2015-12.22

[3] WEST OF DUDDON SANDS Met. Mast (DSMM) Instrumentation Configuration – RES Doc No.: 03039-D5001-01, provided by Axys

[4] “Installation Report AXYS WindSentinel Commissioning and Deployment: West of

Duddon Sands”, issued by AXYS Technologies Inc. on 2015-10-05

[5] ZephIR internal report “Functional test & full performance verification of ZephIR 300 Lidar ZP472” dated 2016-04-04.

[6] IEC 61400-12-1 “Wind turbines – Part 12-1: Power performance measurements of electricity producing wind turbines”, 2005

[7] Draft CDV IEC 61400-12-1, Ed.2 “Wind turbines – Part 12-1: Power performance

measurements of electricity producing wind turbines”, 2015.

[8] MEASNET: “Cup Anemometer Calibration Procedure”. Version 1, September 1997


APPENDIX A – APPLIED KEY PERFORMANCE INDICATORS AND

ACCEPTANCE CRITERIA FOR FLD VERIFICATION Availability / Reliability

The KPIs and Acceptance Criteria relating to availability, all of which are applicable to all measurement heights under consideration, are defined as follows:


Acceptance Criteria

across total campaign duration

OSACA Overall System Availability – Campaign Average

The LiDAR system is ready to function according to specifications and to deliver data, taking into account all

time stamped data entries in the output data files including flagged data (e.g. by NaNs or 9999s) for the pre-defined total campaign length.

The Overall System Availability is the number of those time stamped data entries relative to the maximum possible number of (here 10 minute) data entries including periods of maintenance (regarded as 100%)

within the pre-defined total campaign period.

≥95%

OPDACA Overall Post-processed Data Availability

The Overall Post-processed Data availability is the number of those data entries remaining

after system internal (unseen) filtering, i.e. excluding (NaN or 999) flagged data entries

and after application of quality filters based on system own parameters, to be defined and applied in a post processing step on the basis of LiDAR Manufacturer guidelines

relative to the maximum possible number of (here 10 minute) data entries (regarded as 100%) within the pre-

defined total campaign period regardless of the environmental conditions within this period.

≥85%

Wind Data Accuracy assessment

The KPIs and Acceptance Criteria relating to accuracy are defined in the following table. To assess the accuracy a statistical linear regression approach has been selected which is based on:

a) a two variant regression y = mx+b (with m slope and b offset) to be applied to wind direction data comparisons between floating instrument and the reference ; and,

b) a single variant regression, with the regression analysis constrained to pass through origin (y = mx+b; b = 0) to be applied to wind speed, turbulence intensity and wind shear data comparisons between floating instrument and the reference.

In addition, Acceptance Criteria in the form of “best practise” and “minimum” allowable tolerances have

been imposed on slope and offset values as well as on coefficient of determination returned from each reference height for KPIs related to the primary parameters of interest; wind speed and wind direction.



Acceptance Criteria

Best Practice Minimum

Xmws Mean Wind Speed – Slope

Slope returned from single variant regression with the regression analysis constrained to pass through the origin.

A tolerance is imposed on the Slope value.

Analysis shall be applied to wind speed range

a) all above 2 m/s

given achieved data coverage requirements.

0.98 – 1.02 0.97 – 1.03

R2mws Mean Wind Speed – Coefficient of

Determination

Coefficient returned from single variant

regression

A tolerance is imposed on the Coefficient value.

Analysis shall be applied to wind speed range

a) all above 2 m/s

given achieved data coverage requirements.

>0.98 >0.97

Mmwd Mean Wind Direction – Slope

Slope returned from a two-variant regression.

A tolerance is imposed on the Slope

value.

Analysis shall be applied to

a) all wind directions

b) all wind speeds above 2 m/s

regardless of coverage requirements.

0.97 – 1.03 0.95 – 1.05

OFFmwd Mean Wind Direction – Offset, in terms of the mean WD difference over the total campaign duration

(same as for Mmwd)

< 5° < 10°

R2mwd Mean Wind Direction – Coefficient

of Determination

(same as for Mmwd)

> 0.97 > 0.95


APPENDIX B – CAMPAIGN METEOROLOGICAL CONDITIONS,

TIME SERIES AND WS/WD CORRELATION PLOTS Polar plots of wind directions probability and wind speed for 40 m and 160 m comparison heights:

Time series of air temperature at WRMM location and as measured on the FLIDAR 6M buoy’s short met mast:


Wind speed and wind directions time series for 55 m and 85 m comparison heights:


WS regression plots for three (3) selected comparison heights, i.e. at 55, 70 and 85 m above MSL Shown are results for linear WS regressions “forced” through the origin as discussed above, and for information “un-forced” linear WS regressions, yielding as well the WS offset in terms of intercept of the regression line of the y-axis.


WD correlation plots for three (3) selected comparison heights, i.e. at 55, 70 and 85 m above MSL Shown are results for linear “un-forced” WD regressions, yielding as well the WD offset in terms of intercept of the regression line of the y-axis and in terms of the mean WD difference.


APPENDIX C – WAVES Maximum and significant wave height probability distribution as observed during the WoDS validation campaign:

Campaign maximum wave heights and according wave periods:

Campaign Max Campaign Max

[m] [s]

SIGN Wave Height 5,2 at SIGN Wave Period 8,8

Heighest Wave Height 9,4 at Peak Wave Height 8,7


APPENDIX D – MET MAST SKETCH As-built sketch of Offshore met mast WoDS. Sensors/data distribution to both data loggers indicated by red/green colouring. Sketch taken from [3]


APPENDIX E – SYSTEM AND DATA AVAILABILITY Summary of achievement with regards to system availability (upper table) and data availability (lower table) after the 183 days (6 months) WoDS validation campaign for Roadmap [1] prescribed KPIs and Acceptance Criteria

End of report

Period Start End

#-val ref. #-val 95%/90%

Campaign 29.9.15 0:00 28.3.16 23:50 26208 25990 99,2%

Month1 29.9.15 0:00 28.10.15 23:50 4320 4307 99,7%

Month2 29.10.15 0:00 28.11.15 23:50 4464 4439 99,5%

Month3 29.11.15 0:00 28.12.15 23:50 4320 4301 99,6%

Month4 29.12.15 0:00 28.1.16 23:50 4464 4356 97,6%

Month5 29.1.16 0:00 28.2.16 23:50 4464 4416 98,9%

Month6 29.2.16 0:00 28.3.16 23:50 4176 4171 99,9%

System availability C: 95% | M: 90%

Height [m] 23 45 55 70 85 102 122 152 182 202

Campaign 99,2% 99,2% 99,2% 99,2% 99,2% 99,2% 99,2% 99,2% 99,2% 99,2%

Month1 99,7% 99,7% 99,7% 99,7% 99,7% 99,7% 99,7% 99,7% 99,7% 99,7%

Month2 99,5% 99,5% 99,5% 99,5% 99,5% 99,5% 99,5% 99,5% 99,5% 99,5%

Month3 99,6% 99,6% 99,6% 99,6% 99,6% 99,6% 99,6% 99,6% 99,6% 99,6%

Month4 97,6% 97,6% 97,6% 97,6% 97,6% 97,6% 97,6% 97,6% 97,6% 97,6%

Month5 98,9% 98,9% 98,9% 98,9% 98,9% 98,9% 98,9% 98,9% 98,9% 98,9%

Month6 99,9% 99,9% 99,9% 99,9% 99,9% 99,9% 99,9% 99,9% 99,9% 99,9%

Campaign Overall and Monthly data availability per height level C: 85% | M: 80%

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