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Obtaining the Eastern Wind Dataset

Here you will find information about how to obtain yearly files of time-series and forecast data and Google Earth KML files that show locations of sites and an explanation of what the Eastern Wind Dataset look like.

To obtain data in the Eastern Wind Dataset, you must first read and accept the Data Use Disclaimer Agreement. Once you accept the agreement, you will be able to access data files from a FTP (file transfer protocol) site. You can also access the data by an interactive map that lets you zoom in and select a turbine.

Time-Series Data Files

Yearly files of time-series data can be downloaded from NREL's FTP site. On the FTP site, there are three sets of data files: Land based, offshore, and MISO. Once you download and unzip the files, all data files are in text format, and are in CSV (comma separated values) form.

Land Based

There are 1,326 land-based sites.

• 2004
  You can download four zip files or 34 individual state files. For 2004, AWS-Truewind prepared four files vs. one for 2005 or 2006. All 1326 files are there, you will just have to download and unpack four files for 2004.

• 2005
  You can download one zip file or 34 individual state files.

• 2006
  You can download one zip file or 34 individual state files.

• EWITS_selected_sites.xls or EWITS_selected_sites.txt
  You can download Eastern Wind Integration and Transmission Study (EWITS) site information in Excel format or tab-delimited text format.

Offshore

There are 4,948 offshore sites located along the Atlantic Coast from Maine to North Carolina and in Lakes Michigan, Superior, Huron, and Erie.

• 2004
  You can download one zip file or 17 individual state files.

• 2005
  You can download one zip file or 17 individual state files.

• 2006
  You can download one zip file or 17 individual state files.

• OFFSHORE_selected_sites.csv
  You can download offshore site information in CSV format.

MISO

There are 187 MISO sites located in the Midwest ISO area: North Dakota, South Dakota, Nebraska, Minnesota, Iowa, Missouri, Wisconsin, Illinois, Michigan, Indiana, and Ohio.

• 2004
  You can download one zip file.

• 2005
  You can download one zip file.

• 2006
  You can download one zip file.

• Miso_sites_info.csv
  You can download a CSV file with site locations, capacities, etc.

What the Time-Series Files Look Like

Time-series data files consist of two header lines, followed by 52560 or 52704 (for 2004, a leap year) data lines representing a sample every 10 minutes for 365 (or 366) days. Here is an example of the header lines.

First Line

• Site Number
  Specifies the site number (0001)

• Rated Cap
  Gives the total site capacity in megawatts (MW) (171.8) Rated capacity is a measure (in MW) of how much wind capacity could be installed at the site. It is the product of the size of the site and the turbine density (MW/km2) as determined by AWS-Truewind's model.

• IEC Class
  The IEC turbine class selected for this site, based on the one-year average wind speed. The IEC defines 3 classes of wind turbines for different wind regimes. Roughly speaking, Class 1 turbines are for sites with average speeds of more than 8.5 m/s, Class 2 turbines are for sites with average wind speeds 7.5 m/s to 8.5 m/s. Class 3 turbines are for winds less than 7.5 m/s. All turbines in the plant are the same type (1, 2 or 3) determined from the average wind speed (with an adjustment for site altitude). The IEC class changes from year to year for 158 of the sites; if consistency is important, the lowest class should be used. A list of IEC classes and changes is available in file EWITS_site_class_changes.csv. Note that the IEC classes 1, 2 and 3 describe different wind turbines and have nothing to do with the power classes (1-7) used on wind maps.

• Losses (%)
  Lists the associated losses for IEC classes 1, 2 or 3. The losses are for the three IEC classes. They include availability, soiling, wakes, electrical, etc. The reason they differ somewhat between classes is that the power curves are different. AWS-Truewind subtracts a direction-dependent percentage from the wind speed to account for wakes and the impact of that reduction varies depending on where on the power curve the turbine is operating.

Second Line

The second header line describes the individual data fields.

• Date-GMT
  The date is in YYYYMMDD form.

• Time-GMT
  The time is given as GMT (UTC) times.

• Speed80M and Speed 100M
  These columns give the modeled speed at 80 meters and 100 meters above ground.

• IEC1-80M, IEC2-80M, and IEC3-100M
  The three IEC columns give the modeled power output (in MW) of the site assuming that all installed turbines are of IEC class 1, 2 or 3. Composite power curves for IEC 1 and 2 are based on a composite of 3 machines (GE, Vestas, Gamesa), while the IEC 3 curve is based on the GE 1.5xle and the Gamesa G90.

• Selected
  The SELECTED column is always equal to one of the three previous columns, namely that of the IEC class specified in the first header line. This is useful because you can always look in the SELECTED column to find the power output without worrying about which column to choose. You can always look in the same column for the appropriate power output data, regardless of which class was selected. The program sets the IEC class equal to the lowest class encountered among the mesoscale grid cells associated with the site. The rationale for this logic is that a class I machine can be placed at a class II location but not the reverse. A further assumption is that the developer would not want to have a mix of turbine types at a site.

Data records look like this:

20040101, 10, 6.298, 6.607, 19.0, 23.6, 30.0, 19.0
20040101, 20, 6.437, 6.743, 21.8, 26.9, 34.1, 21.8
20040101, 30, 6.841, 7.216, 28.5, 34.8, 44.2, 28.5
20040101, 40, 7.486, 7.929, 34.8, 42.1, 54.2, 34.8
20040101, 50, 8.575, 9.079, 56.2, 65.9, 83.0, 56.2
20040101, 100, 9.999, 10.531, 86.5, 97.3, 115.9, 86.5

The dataset contains all the actual data that we have, although AWS-Truewind undoubtedly has additional data, such as direction data, temperature, and humidity, that they used in the modeling.

Forecast Data Files

Yearly files of forecast data can be downloaded from NREL's FTP site. On the FTP site, the forecasts folder contains three sets of files. Once you download and unzip the files, all data files are in text format, and are in CSV (comma separated values) form.

Forecasts

• Land Based
  You can download day-ahead, 6-hour and 4-hour forecasts for 2004-2006. There are nine zip files in total.

• Offshore
  You can download day-ahead, 6-hour and 4-hour forecasts for 2004-2006. There are nine zip files in total.

• MISO
  You can download day-ahead, 6-hour and 4-hour forecasts for 2004-2006. There are nine zip files in total.

Forecast data files have a single header line listing the columns in the data records. Here is an example.

Date and time are in GMT (UTC). OBSPWR is the average power observed (modeled power averaged over 6 samples) during the one-hour period, and FCSTPWR is the forecast power. ERR is computed as (FCSTPWR minus OBSPWR). All values are in megawatts (MW).

KML

On the FTP site, this folder contains Google Earth KML files showing locations of sites.

Google Earth reads KML files, so you can view the site locations and basic information. The basic file is ewits_sites.kml, which just has site locations. The other files ('blob_XXXX.kml', etc) categorize sites by wind speed, power, etc. Make sure you download all the legend_XX.png files too so you can see what the different colors mean.

Site location files for MISO and offshore points are also in the KML folder: ewits_miso_sites.kml and ewits_offshore_sites.kml.

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