|
Wind Measurements
Please click here to download the wind measurement progress plan
Project Mariah is located in the north western part of Texas
Project Mariah in Texas
Palmer County, TX
The landscape is open and flat farmland with very few and gentle slopes and hills as can be seen above.
The project area constitutes about half of the county 30 by 30 km as depicted the below. With current planning it will have approximately 900 turbines with a total possible installed capacity in excess of 3000 MW.
Project Mariah in Palmer County.
Available wind data
The wind resource in the area can be estimated from several open sources:
3 Tier provides an estimate of 6.8-8.9 m/s for the area with an 80 m hub height. This is compared to other areas a fairly narrow band estimate and points to approximately 7.8 m/s wind resource. The available open source measurements in Texas are shown below. AEI has published and maintains this list of data.
The most interesting measurement site is the 100 m tower in Mariah Mast within the project area.
Wind measurement data available for Texas.
The sensor installation and the data for the Bovina tower have been reviewed with the following main conclusions:
- The tower is located on the outskirts of the Bovina town area which means that wind data will be effected by the structures within the city
- The sensor installation does not comply with the industry de facto standard (IEC 61400-12-1). The sensor booms hold both an anemometer and a wind vane on the same boom. The sensors are not mounted on a vertical boom rising from the horizontal part of the boom
- Sensor calibrations have not been applied to the data although this will have very little effect on the data
- Data is available from July 2006 until present with some gaps
- The average wind speed derived from the top mounted anemometer is 8.3 m/
- Even with the limitations of 3Tier and issues identified with the measurements in Bovina a wind resource above 7.5 m/s seems likely.
Plan
In order establish the wind resource accurate enough towards a final bankable production estimate for project Mariah, new measurements have to be performed. Once a final layout of the wind farm is available, analysis needs to be completed to ensure that the initial measurements implemented, are sufficient. Further measurements may be identified. The plan will therefore be developed as more data from measurements and site layout become available.
- The initial plan contains the following:
- Document the installation of the tower in Bovina (named Mariah Mast 1 in this plan)
- Perform a detailed analysis of the Mariah Mast 1 data
- Install measurement equipment in two additional towers within the project area (named Mariah Mast 2 and 3 in this plan)
- Tracking and analysis of data from Mariah Mast 1, 2 and 3.
- Build a model in WindPRO or similar of total project area for the purpose of analysis of any further measurements and use in subsequent production analysis
Document the Mariah Mast 1 installation
As mentioned earlier the installation in Mariah Mast 1 does not comply with several aspects of normal practice. Never the less several years of data is available and when simultaneous data from Mariah Mast 2 and 3 become available, it will investigated whether correlation between towers can be shown. If that is the case, the uncertainty of the data from Mariah Mast 1 will be less.
In order to use the data from Mariah Mast 1 the installation data generated by AEI has been reviewed. The AEI installation report provided the information needed for using the data in wind data analysis.
Detailed analysis of Mariah Mast 1 data
The mean wind speed from Mariah Mast 1 mentioned earlier has been derived without accounting for the issues with the sensor installation. A detailed analysis will be performed taking these issues into account and could lead to a revised mean wind speed. This revised wind speed will form the basis for the first analysis of energy production of the wind farm.
Installation of measurement equipment in Mariah Mast 2 and 3
Two existing towers within the project area have been selected for installation of measurement equipment. The towers are known as KJIN (radio tower) and Slagle #1. These two towers will become Mariah Mast 2 and 3. The location of all three towers is shown below.
The installation of equipment will be performed in accordance with industry standards (IEC 61400-12-1) and documented in accordance with standard AWE procedure (attachment 1).
The following will be installed:
- Mariah Mast 1:
- Iridium satellite modem such that data can be sent weekly to AWE rather than manual download
- Already installed are:
- 2 anemometers each at approximately 100, 75 and 50 m
- Wind vanes at approximately 100, 75 and 50 m
- Data logger
- Mariah Mast 2 (KIJN)
- 2 anemometers each at approximately 150, 125, 100 and 75 m
- Wind vanes at approximately 150, 125, 100 and 75 m
- Temperature sensor at approximately 150 m
- Pressure and solar radiation sensor at approximately 5 m
- Datalogger with solar panel and Iridium satellite modem at approximately 5 m
- Mariah Mast 3 (Slagle #1)
- 2 anemometers each at approximately 100, 80 and 60 m
- Wind vanes at approximately 100, 80 and 60 m
- Temperature, pressure and solar radiation sensor at approximately 5 m
- Datalogger with solar panel and Iridium satellite modem at approximately 5 m
Tracking and analysis of data from Mariah Mast 1, 2 and 3
Once all three sites have modems installed data will tracked on a weekly basis in accordance with AWE standard procedures (attachment 2). This will ensure data quality is checked and any issues are dealt with. It will also build up the knowledge of the wind resource for input to the production analysis. Measurements will have to be conducted for at least one year and more likely will continue for two years.
Building of model in WindPRO of project and further analysis
A model of the wind farm will have to be built in WindPRO or similar for many purposes beyond wind measurement. The plan for this therefore has to be coordinated with these other efforts.
The main output from a wind measurement perspective will be:
- Wind resource map for the entire project
- Assist in determining need for further measurements
- Provide production estimate from the wind farm
Update of the plan
This plan is anticipated to be living document that will updated regularly as Project Mariah develops. The plan shall therefore be updated quarterly. Activities shown in section 2 list the currently identified needs. Additional other activities that may be needed could include:
- Measurements in additional towers
- Measurements with LIDAR or similar sensor
 
Jens Petersen, Alpha Wind Energy, rigging a wind data Boom to Mast for Mariah Project between Mariah Mast and Friona Texas June 12, 2009
Acknowledgement
AWE wishes to acknowledge Alternative Energy Institute (AEI) of West Texas A&M University for the effort AEI puts into promoting wind energy in Texas. The data available from AEI on wind resource in Texas has been a very good starting point for AWE into the Panhandle area. The Mariah Mast 1 installed and maintained by AEI provided specific very good insight into the Parmer area and was a contributing factor for AWE to decide to pursue Parmer County.
|
