Measurements at the Horns Rev offshore wind farm. Establishment ...

REPORT 

May 30, 2002 

Phone: +45 79 23 33 33 

Fax: +45 75 56 44 77 

Our ref.: PBS/hdp 

Report no.: 02-839 

Project no.: 12947 

Pages: 22 + Enclosures 

Verified: Approved: 

Eltra PSO 2001/no. 3192 

MEASUREMENTS AT THE HORNS REV OFFSHORE WIND FARM 

Establishment of Meteorology Measuring Stations in the Horns Rev Wind Farm 

Tech-wise A/S is an international consulting Tech-wise A/S 

engineering company specialised Kraftværksvej 53 

in energy and environment DK-7000 Fredericia

energy. environment. knowledge. Page i 


Table of Contents 

0. Edition.........................................................................................................................1 

1. Project Background.....................................................................................................2 

1.1 Basic Points .......................................................................................................2 

2. Objectives ...................................................................................................................3 

3. Options........................................................................................................................4 

4. Overall Measuring System..........................................................................................5 

4.1 Measuring Systems............................................................................................5 

4.2 Meteorological System......................................................................................5 

4.2.1 Placement of Sensors ..........................................................................5 

4.3 Boom Layout.....................................................................................................6 

5. System Specifications .................................................................................................7 

5.1 Main System Specifications ..............................................................................7 

5.2 Specifications of Statistical Met Data ...............................................................7 

5.3 Specifications of Met Back-up System .............................................................8 

5.4 Specifications of Computers..............................................................................8 

5.5 Spare Sensors.....................................................................................................9 

6. Data 10 

6.1 Type of Data Records......................................................................................10 

6.2 Data Acquisition for Met Statistics .................................................................11 

6.3 Data Acquisition for Met Back-up System .....................................................12 

6.4 Synchronisation of Data ..................................................................................12 

6.5 Programs for Data Handling............................................................................12 

6.6 Data Quality.....................................................................................................13 

7. Power Supply............................................................................................................14 

7.1 Power Supply for Statistical Met Data ............................................................14 

7.2 Power Supply for Met Back-up System ..........................................................14 

8. Lattice Tower and Hut ..............................................................................................15 

8.1 Lattice Tower...................................................................................................15 

8.2 Warning Systems.............................................................................................15 

8.3 Lightning Protection........................................................................................16 

8.4 Equipment Hut.................................................................................................16 

8.5 Buoyage...........................................................................................................16 

9. System Operation and Maintenance .........................................................................17 

9.1 System Operation ............................................................................................17 

9.2 System Maintenance........................................................................................17 

9.3 Experiences from the Horns Rev and Læsø Met Station ................................17 

10. Conceptual Descriptions ...........................................................................................18 

10.1 Pre-assembly and Transport ............................................................................18 

10.2 Assembly and Test at Sub-supplier .................................................................18 

10.3 Tower Erection ................................................................................................18 

10.4 Installation of Equipment ................................................................................19 

11. Implementation .........................................................................................................20 

11.1 Proposed Implementation Procedure...............................................................20 

12. Enclosures .................................................................................................................21 

13. References.................................................................................................................22 

Z:\Planlægning\Miljø og PSO-F&U\Dokumenter\Afslutningsrapporter til Risø\originaldata\ingen afslutningsrapport\3192\Parkmaster\1 Rapport\n839pbs.doc 




energy. environment. knowledge. Page 1 of 24 

0. Edition 


Edition: 

Edition No Version Date Changes 

01 30.05.2002 Working copy is not subjected to QA control – May be changed without 

any notice 

Distribution list: 

Edition No Elsam-PF TW-PBS TW-JPE TW-JOP TW-SNE TW-UKJ 

01 X - - X - - - - 

NB: Only ticked off members of the latest edition will automatically be updated. 






1. Project Background 


The overall project goal is to provide wind data for the Horns Rev demonstration 

project which serves to support the measurements according to the Danish Power 

Supply act. The project establishes and initiates measuring stations (Met. Stations), by 

which it will be possible: 

To investigate the relation between the atmosphere and offshore wind farm for 

verification and enhancing the design basis; specially with focus on the turbulence 

down the park 

In co-operation with an other project to measure the big scale effect from the park 

(e.g. shadow) 

To do measuring of load response on the turbines placed close to the met stations 

The project takes advantage of the large amount of experiences gained during design, 

planning, installation, O&M of the Met. Stations on the Horns Rev and south of Læsø in 

Denmark. 

1.1 Basic Points 

The system should be very reliable. Therefore, it has been decided to base the 

design (sensors, data acquisition and communication, tower and supporting 

structure) on the proven technology of the existing offshore met station M2 at Horns 

Rev. 

The measurements have to be carried out according to best practices and current 

standards. 






2. Objectives 


The objective of the present report is to describe the design specifications for the 

proposed offshore met station. The object of the measurements is to improve the 

understanding of: 

The relation between the atmosphere and offshore wind farm for verification and 

enhancing the design basis; specially with focus on the turbulence down the park. 

The objectives of this report are: 

To provide a general description of the measurement system; 

To provide the technical specifications of the required sensors (meteorological), data 

acquisition, power supply, lattice tower and hut; and 

To provide conceptual descriptions of pre-assembly, transport, erection and 

installation of tower and equipment, and implementation aspects. 






3. Options 

Option 1: 2-year operation & maintenance agreement. 







4. Overall Measuring System 

The purpose of recording data is among others: 


To investigate the relation between the atmosphere and offshore wind farm for 

verification and enhancing the design basis; specially with focus on the turbulence 

down the park. 

The met station comprises two in principle different measuring systems whose data can 

be combined in different ways. The systems are described below. 

4.1 Measuring Systems 

Sys. 1. Statistical Met Data 

The system continuously collects meteorological data at 2 Hz. The data are recorded at 

5 levels, including the top of the mast. The system uses cup anemometers for measuring 

wind speed; 3D-sonic anemometers for recording wind speed/direction; and 

thermometers for recording air and water temperature. Furthermore charging of 

batteries and battery voltage are measured. 

Sys. 2. Met Back-up System 

The meteorological back-up system continuously collects meteorological data at 2Hz. 

The data are recorded at one level, near the top of the mast. The system uses a cup 

anemometer for measuring wind speed and a wind vane for wind direction. The system 

is completely independent of Sys. 1 and acts as a back up of that system. 

4.2 Meteorological System 

This section describes the overall meteorological measuring system. The system is 

placed on a lattice mast and in the hut onto the platform. 

4.2.1 Placement of Sensors 

At the met station most of the sensors will be placed on different booms (horizontal 

beam or tube bolted to the tower). The boom reference levels are shown in the table 

below. 






Level Measurement parameter System Unit 

70 m Wind speed Sys. 1 m/s 

Wind speed Sys. 1 m/s 

68 m 

Wind direction/ 3D-sonic Sys. 1 m/s, X,Y,Z 

66 m 

Wind speed 

Wind direction 

Sys. 2 

Sys. 2 

m/s 

Deg. 

64 m Air temperature Sys. 1 C° 

50 m 

Wind speed 

Wind speed 

Sys. 1 

Sys. 1 

m/s 

m/s 


30 m 

Wind speed 

Wind speed 

Sys. 1 

Sys. 1 

m/s 

m/s 

28 m Wind direction/ 3D-sonic Sys. 1 m/s, X,Y,Z 


16m 

Air temperature 

Air pressure 

Sys. 1 

Sys. 1 

C° 

hPa 

TABLE 1. Parameters measured at different levels relative to Mean Sea Level (MSL). 

The mast layout is shown in Encl. 1 and Encl. 2. 

4.3 Boom Layout 

Booms (tubes or beams) are used for mounting of sensors, cables etc. 


At each level one or two booms will be used for mounting of anemometers or direction 

sensors (except of top boom). Each boom is mounted on a corner of the rectangular 

lattice tower to cover the largest possible wind sector and minimise the influence of the 

tower disturbance, see Encl. 2. 






5. System Specifications 

The system is designed on basis of the first Horns Rev met station concept. 

5.1 Main System Specifications 

The general system specifications are: 


The measuring systems comply with: 

Wind speeds from 1 to 75 m/s; 

All measuring systems are capable of automatic restart after stop or power failure 

etc.; 

The demands to anemometers, calibration and minimum distance to tower etc. fulfil 

the IEA recommendations and the IEC 61400-121 Annex G (Ref. 1); 

Sensors, fittings, cables etc. are resistant against solar radiation and protected 

against corrosion corresponding to class IM2, according to SD/EN ISO 12944-2; 

All pressure and temperature sensors are housed in aspirated shields; 

All sensors are galvanically insulated from other adjoining electrical parts. 

5.2 Specifications of Statistical Met Data 

System requirements: 

Parameter Unit Range Accuracy 

Wind speed m/s [0;75] +/- 0.5 

Win-d direction, 3D-sonic m/s [X,Y,Z] +/- 2.5 

Air temperature C° [-20;40] +/-0.5 

Air pressure HPa [850;1100] +/-2.5 

TABLE 2. Specifications of Statistical Met Data. 

Sampling rate 2Hz. 

The system measures 10-min. period data. After each period the statistical data 

(min, max, standard deviation and mean, 3-s gust) are stored by datalogger. A 3-s 

gust is defined as the max running 3-s mean value for a 10-min. period. 

The data are recorded by a data logger, which collects data in a circular buffer. The 

data logger is designed to the sensors used and can store more than 6 month of 

statistical data. 

The cup anemometers are of the "RISØ type" and comply with the demands of 

accuracy, tolerances to inclined airflow etc. 

The Data Logger DT800 has been chosen to accomplish the demands to the systems. 

Measurements of 3 dimensional wind speeds will be don with sonic anemometers from 

Metsupport, the Danish agent for Metek sonic anemometers (Appendix 10.8). 







Some Specifications of the Data Logger DT800 

16 Bit resolution. 

Input signals: +/-2.5 VDC resolution 1µV, +/-25mA resolution 10µA. 

Temporary data storage for up to 10-min. 

Data manipulation: Statistical data - min, max, standard deviation and gust 

calculation. 

Programmable: Period length, date-time, re-boot etc. 

Storing of data for up to 12 months of statistical data. 

Internal power supply (batteries) for at least 6 months of operation. 

5.3 Specifications of Met Back-up System 

A complete set of AANDERAA system placed near the top anemometer. (Named Sys. 

2). 

System specifications: 

Parameter Unit Range Accuracy 

Wind speed m/s [0;75] +/-0.5 

Wind direction Deg [0;360] +/-5.0 

TABLE 3. Specifications of Met Back-up System 

Sampling rate: 2 Hz. 

Recording wind speed and direction in one level. 

Is completely independent of Sys. 1, both electrically and physically. 

Is able to store data for at least 12 months. 

Internal power supply (batteries) for at least 9 months of operation. 

5.4 Specifications of Computers 

A personal computer (PC) is used for retrieving, converting and storing data to a 

database and for back up. 

No Name Type Data Notes 

1 Onshore Data PC#1 Stationary Scaled data 

TABLE 4. Requirements to computer 

The PC data are: 

IBM compatible PC; 

CPU speed more than 500 MHz; 

Windows 2000 or Windows NT Build 3 or newer; 

Retrieving data through a communication line 

Generating data to SQL database 

Server for other parties 






More than 128 MB Ram and 10 GB Hard disc; 

K56Flex modem or better. 

The computer is not included in the delivery. 

5.5 Spare Sensors 

The spare parts are suggested to be as follows: 

9 cup anemometers 

1 Converter for cup anemometer 

1 wind vanes 

1 Converter for wind vane 

0 DT800 loggers 

0 Memory card for data logger 

1 Temperature sensor 

2 Data Storing Unit 262 Kb, sys. 2 

2 Battery box, sys. 2 

2 Battery pack, sys. 2 

This spare part list ensures that it is possible to make calibration of sensors ahead of the 

½-year exchange of sensors and thereby reduces O&M costs significantly. 

Furthermore, this list assures availability of components, which have a long delivery 

time. 







6. Data 

This section describes the type of data, data acquisition, their handling and quality. 

6.1 Type of Data Records 


TABLE 5 to table 6 gives a brief demonstration of which records are delivered to the 

database. Furthermore, the tables show the number of sensors and where data is 

retrieved. The data type (typ.) is marked by H (data in Header), or S (statistical data). 

Description Typ. No Records: Met statistical data Origin 

Identification H 1 Date and time in file header PC clock 

Sensor no H 1 No. in file header 

Wind speed S 8*5 

10-min. Statistic: 

Max, min, mean, standard deviation, 3-s 

gust (max of running 3-s mean) 

Appended before transferring 

to SQL database 

Sys.1: 

Circular buffer in data logger 

Wind direction S 2*6 10-min. statistic: Mean, standard deviation Sys.3: 

Circular buffer in PC 

Air temperature S 2*3 10-min. statistic: Max, min, mean 

Sys.1: 


Water temperature S 1*3 10-min. statistic: Max, min, mean 

Sys.1: 


Air pressure S 1*3 10-min. statistic: Max, min, mean 

Battery charge S 1*1 10-min. statistic: Mean 

Battery discharge S 1*1 10-min. statistic: Mean 

Battery voltage S 1*1 10-min. statistic: Mean 

Total H/S 2/67 No. of sensors: 16 (Sys. 1+3) 

TABLE 5. Data record types for met statistical data. 

Sys.1: 


Sys.1: 


Sys.1: 


Sys.1: 







Description Typ. No Records: 

Met statistical back-up data 

Origin 


Identification H 1 Date and time in file header Data logger clock 

Sensor no H 1 No. in file header 

Appended before transferring 

to database 

Wind speed S 1*2 

Wind direction S 1*1 

10-min. statistic: 

Mean, 2 sec gust (max of running 2s 

mean) 

10-min. statistic: 

Mean 

Total no. of data H/S 2/3 No. of sensors: 2 (Sys. 2) 

TABLE 6. Data record types for met statistical back-up data - Option 2. 

6.2 Data Acquisition for Met Statistics 

Sys. 2: 


Sys. 2: 


To generate a measurement record 10-min. statistics, data are extracted from Sys. 1 and 

3. 

Data from the systems are stored in the database. 

Handling Met Statistics (Record in TABLE 5) 

1. 10-min. measuring values are stored on a changeable PCMCIA Memory card 

installed in a DT-800 data logger with a storage capacity of at least 6 months. After 

this period old data are overwritten by the latest measuring data. The PCMCIA card 

contains station ID (M3, M4 or M5), date/time of stored 10-min. values as well as a 

program for Data logger specifying sensor channel, sensor type, span ranges 

(scaling factors) as well as scan frequency of the individual schedules, including 

statistical scan, alarms etc. 

2. As arranged GSM 900/1800 has been chosen as transmission system for transfer of 

data between the measuring systems on M3, M4 and M5 masts and the Owner’s PC 

at Tech-wise A/S in Fredericia. Data are transferred as ASCII characters in a text 

string, comprising all calculated numerical values from the measured channels. 

Further data validation is not included in the supply, as the Owner manages supply 

of the data collecting program and PC at Tech-wise A/S. 

3. The onshore PC shall scale the ASCII data using calibration information. 

4. The onshore PC shall store scaled ASCII data into the database. 

5. The data shall be checked manually by plotting wind speed, wind direction, air 

temperature, barometric pressure, battery voltage, battery charge and discharge etc. 






6. Quality check shall be made. If errors are found the database is adjusted accordingly 

(removal, fault mark). 

All 10-min. statistical raw and scaled data shall be stored as back up on tape or CD- 

Rom by the onshore computer. 

6.3 Data Acquisition for Met Back-up System 


Handling Met Back-up System 

The data are handled as for Sys. 1 except that fewer data is available. Only wind speed 

and direction is available for a single level. 

Furthermore the data handling is different from 2 and 3 in section 6.2. 

2. During a visit to the met station the “full” data logger is exchanged with an “empty” 

data logger. 

3. The data logger is connected to a special interface card in the onshore PC and data 

are extracted to the PC. 

6.4 Synchronisation of Data 

The data are synchronised as follows: 

The system clock from which the data is retrieved and defined as Logged Time 

identifies the data. 

When the data are put into the onshore database a small program adjusts the data to 

the Database Time by rounding down to a 10-min. time logged by Sys. 1. 

6.5 Programs for Data Handling 

It is suggested to develop the tools briefly mentioned here. 

Purpose Program Notes 

Generating calibration files Excel Macro All calibration data are stored in one file 

Converting raw data from Sys. 1 to scaled Integrated in Appending sensor no. and common time 

ASCII data 

supplier’s software. 

Retrieving data from Sys. 1 via a 

communication line 

Made by supplier Stores data on onshore PC#1 

Extracting data from data logger in Sys. 2 Data Reading Program Made by supplier (AANDERAA 

Instruments) 

Extracting data from database to report Any program with 

ODBC/SQL interface 

Chosen by time, sensor numbers 

TABLE 7. Programs for data handling 






More programs may have to be made to analyse the recorded data. 

6.6 Data Quality 

A quality system will be established to ensure a high quality of the measurements. To 

accommodate this, the following methodology will be used: 


Before Installation and during Commissioning 

1. The sensors and the system will be calibrated on shore by recognised methods and 

institutes. 

2. Measurement chains (from sensor to data received onshore) will be calibrated 

during the onshore test. 

3. The separate back up of the wind speed and direction measurement system ensures 

that the main data will be available even if the primary system fails. This has been 

proven to work at the Horns Rev station. 

During Semi-Industrial Operation period 

1. The sensor outputs must be checked by visual inspection, looking for discrepancies 

between min/max/mean values and between the different sensors. 

2. All measured data wills be stored and a back up made to ensure traceability. These 

data must be stored in a place physically separated from that of the onshore PC. 






7. Power Supply 

This section describes the main specifications for the different power supplies. 

7.1 Power Supply for Statistical Met Data 

The power supply for the Statistical Met Data system is based on a cable connection 

from a wind turbine combined with batteries. 

The figures below are derived from the data from the Horns Rev met station. 

The demands to the power supply for the Statistical Met Data are: 

Main System 

Power supply system from wind turbine : 400 V 

Continuous consumption over a day : 16 W 

System voltage : 24 V DC 

Current needed per hour : 16 Ah 

Battery Package for the Buoyage System 

Battery type : BAE Solar Block 

No. of batteries/capacity : 1 x 12 V / 102Ah, C10 

Minimum voltage : 11 V DC 

Nominal voltage : 13.7 V DC = 100% capacity 

The solution gives a possibility of 30 days autonomous operation that is power is 

supplied only by the batteries. 

7.2 Power Supply for Met Back-up System 

The power supply for the Met Back-up System is a separate power battery system 

lasting for at least 6 months. 







8. Lattice Tower and Hut 

This section describes the tower, lightning protection and hut. 

8.1 Lattice Tower 

The main specifications of the tower are: 


The tower is a lattice tower structure build by steel lattice square sections. 

It is possible to climb up inside the mast for maintenance of the sensors etc. 

Resting platforms inside the mast are installed for every 12 – 22 m. 

The lattice sections are assembled by means of bolts. 

The base lattice section is via an "anchor plate" bolted onto the platform. It is 

possible to correct the inclination of the mast by up to +/-0.5° (in case the platform 

is not in horizontal position). 

A hut with measurement equipment is placed “inside” the lattice frame on the 

base/platform. 

No measures for protection against lightning strikes for the mast itself are taken. 

The mast is provided with personal safety equipment, ladders and cable trays etc. 

The mast is protected against corrosion corresponding to class IM2, according to 

SD/EN ISO 12944-2 

The mast is hot-dip galvanised. 

The bolt connections fulfil DS412 for bolted connections. 

The mast is designed for loads according to wind loads described in the tender. 

The mast has the following main data (level: Level above MSL): 

Level of top anemometer : 70 m 

Length of stay for top anemometer : 2 m 

Level of top of lattice tower : 68 m 

Length of mast sections : 59 m 

Level of platform for bolting of lattice tower : 9 m 

Necessary hoisting height : 63 m 

Weight (incl. Booms and equipment on mast) : 18 t (approx.) 

The complete tower and the base section of lattice mast are shown in Encl. 1 and Encl. 

2. 

8.2 Warning Systems 

The Contractor will mount the met station with warning systems according to the 

Clients instructions. This work is assumed to be limited to 10 hours. 






8.3 Lightning Protection 


The Horns Rev mast M2 is not equipped with lightning protection because the risk of 

being struck by lightning was found to be low for the site. The mean density of 

lightning strikes in the period of 1990-1996 in Denmark was 0.23 annual strikes per 

km². 

It has been assumed that the risk of being struck by lightning is approx. the same for the 

chosen position and hence this met station need not be equipped with lightning 

protection for the mast itself. 

8.4 Equipment Hut 

Inside the base of the mast there will be a small room (a hut) to contain and protect the 

data acquisition systems and batteries and some spare parts. 

Specifications of the hut: 

The hut protects the equipment against sun, rain and spray from the waves. 

The hut contains batteries, data acquisition, switchboards, a table and a chair, 

manuals etc. 

The hut contains survival kid for two persons for 14 days. 

The hut is without insulation, air conditioning or heating. 

The hut will be squared inside approx. 1.9x1.9x2.2 m 

The hut has a low powered lighting to allow working in there. 

There are a few bookcases for manuals, logs etc. 

The hut is placed on the platform at the base of the mast. It has been chosen to place the 

platform 9 m above MSL in order to keep it above the expected maximum wave crests. 

8.5 Buoyage 

Mast M3 is equipped with two lanterns with lighthouse character for the letter ”U” 

(danger ahead). Two short and one long light signals are given at intervals of 15 sec. 






9. System Operation and Maintenance 

This section describes how the measuring system must be operated and maintenance 

performed. 

9.1 System Operation 


Meteorological Data 

1. On a regular basis data must be collected from the primary system, transferred to the 

database and their quality checked. 

2. During service visits, data from the back-up measurement system must be collected. 

9.2 System Maintenance 

The measuring systems are designed in co-operation with their suppliers and in a way 

that minimises maintenance of mechanical and electrical parts and secures power supply 

equipment. 

The supplier of anemometers, data loggers etc. maintains a sufficient stock for 

scheduled and unscheduled service visits, in such a way that a service visit not will be 

obstructed because of long delivery time of components. These parts will be provided as 

the spare parts procured within this order - if the option for the spare part list is agreed 

upon. 

The batteries in the back-up system have to be changed on a regular basis (approx. to 

times a year). 

9.3 Experiences from the Horns Rev and Læsø Met Station 

The Horns Rev met station (M2) has been in operation from May 1999 until now. In 

summary the experiences from the met station are as follows: 

1. The availability of the measurement system has been 96 - 100% for meteorological 

measurements and 60 – 90% for marine measurements. 

2. During the hurricane a small vertical axis wind turbine broke down (a blade came 

off). The turbine supplies the fifth system (ultrasonic sensors for research purposes) 

which was not in operation at the time of the event. 

3. Data have been presented at various seminars and conferences (e.g. OWEMES in 

Sicily) showing the fine behaviour of the measuring system and some unexpected 

situations, such as the December hurricane. 






10. Conceptual Descriptions 

This section describes in a conceptual way assembly, transport and installation of 

components and equipment. 

The descriptions below are just indicative suggestions. 

10.1 Pre-assembly and Transport 

Before shipping the equipment, the pre-assembly is suggested to be grouped as follows: 


The lattice tower is assembled in one suitable section, complete with ladders (cable 

trays), platforms and safety equipment. 

The cables (with both ends plugged) are mounted in the cable trays. 

The fittings for all booms for the different sensors are placed at the correct levels on 

the tower. The booms are fastened in a vertical position inside the tower (prepositioned). 

The hut and the lowest section of the tower are assembled together in a vertical 

position. 

All equipment (sensors, beacons etc.) is safely stored in the hut for transportation. 

Encl. 3 shows some photos from the Horns Rev installation. 

10.2 Assembly and Test at Sub-supplier 

The complete meteorological measuring system is assembled and tested at one of the 

sub-supplier workshop. Test reports are made for the complete system. 

10.3 Tower Erection 

The tower is erected as follows (assuming a mono pile is used): 

1. The mono pile, platform, boat-landing arrangement, hut and lattice tower are placed 

on a barge. 

2. When the weather condition allows it, the barge and a jack-up or another suitable 

vessel with a sufficient crane and piling unit are towed to the site. 

3. The exact spot is found, e.g. by means of GPS. 

4. The mono pile is driven into the right depth. 

5. The top of the mono pile is prepared for the platform. 

6. The boat landing arrangement is fitted to the mono pile. 

7. The platform is put on top of the mono pile. 

8. The exact orientation of the platform is found, e.g. by means of GPS. 

9. The platform is welded to the mono pile. 






10. The integrated hut and lowest section of the tower are placed on the platform. 

11. The upper section of the tower is erected. 

12. Other works, such as paintwork, are carried out. 

10.4 Installation of Equipment 

The equipment is installed as follows: 

1. The pre-positioned booms are mounted in the fittings. 

2. The sensors are fitted to the booms. 

3. The booms are pushed into the right position and bolted. 

4. The pre-laid cables are connected to the sensors and to the equipment in the hut. 

5. The PV panels are fitted to the tower and connected to the battery charge etc. 

6. The data loggers are connected to the power supply. 

7. The communication systems are connected. 

8. All remaining equipment and systems are thoroughly tested. 







11. Implementation 

11.1 Proposed Implementation Procedure 

The implementation procedure could be as follows: 

1. Procurement of measurement equipment. 

2. Installation of system at the developer site nearby onshore site or workshop. 

3. Testing all systems in workshop. 

4. Obtaining permissions for the offshore installation. 

5. Signing contracts with contractors. 

6. Installation of offshore foundation. 

7. Installation of local PC system (recording data via communication line). 

8. Pre-assembly onshore. 

9. Loading barge with equipment. 

10. Transport of equipment to offshore site. 

11. Installation of equipment on offshore site. 

12. Testing all systems on offshore site. 







12. Enclosures 

Encl. 1. Offshore Met Station. Lattice mast. May, 2002, Tech-wise A/S 

Encl. 2. Offshore Met Station. Boom and base section of lattice mast. May, 2002, 

Tech-wise A/S 

Encl. 3. Photos of part of lattice mast for the Horns Rev installation. 1999, Tech-wise 

A/S 







13. References 

Ref. 1. IEC 61400-121, Annex G. 

Ref. 2. DS412, Code of Practice for Structural use of Steel. Dansk Standard, 3. 

Udg/1.oplag, Approved: 1998-07-02. 







Encl. 1 

Offshore Met Station. Lattice mast. 

May 2002, Tech-wise A/S 




in energy and environment DK-7000 Fredericia 

Encl. 1


Encl. 2 

Offshore Met Station. Boom and base section of lattice mast. 

May 2002, Tech-wise A/S 





Encl. 2


Encl. 3 

Photos of part of lattice mast for the Horns Rev installation 

1999, Tech-wise A/S 





Encl. 3

Measurements at the Horns Rev offshore wind farm. Establishment ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?