Last update: November 14, 2008

WRAN users: we want to hear from you. We are considering making some changes to the types of data posted on this site. Specifically, it seems that most users need only the monthly data files, so we are considering focusing our efforts on those instead of the graphical reports. If you are a user of WRAN data, we would like to hear from you as to how you use the data, and what would make it more useful to you. Please drop us a line at dennis.todey@sdstate.edu

To ask questions about this site, the WRAN, or the data, or to request raw data or alternate formats, please contact:
Dr. Dennis Todey
Agricultural Engineering
South Dakota State University
Brookings, SD 57007
Ph: (605) 688-5678

Table of Contents

• Data: Crandall | Crow Lake | Ft. Thompson | Leola | Summit | More downloads | Dynamic data
• Wran News
• Data: Summary data from all sites
  • Ft. Thompson
  • Crow Lake
  • Leola
  • Crandall
  • Summit
  • Gettysburg
  • Murdo
  • Belle Fourche
  • Medicine Butte Ridgeline
  • Faith
  • Martin
• What is WRAN?
• What is the purpose of WRAN?
• Who is responsible for WRAN?
• Wind turbines at work: phones and short video of wind turbines

What is WRAN?

Figure 1: Transmission Lines/Wind Speed 

The Wind Resource Assessment Networks 2001 sites are owned by South Dakota State. They are Ft. Thompson, Crow Lake, Crandall, Leola, and Summit. Each site is equipped with the following instruments:

• 4 anemometers, 2 at each elevation of 50-meters and 70-meters above ground
• 2 wind direction vanes, 1 at each height
• 1 pyranometer (solar irradiance measurement device) at ground level, mounted horizontally
• 1 datalogger to record measurements at regular 10-minute intervals

The 2004, 2005, and 2006 sites are equipped with a different than the previous towers.

• Gettysburg's WRAN tower is owned locally by Gettysburg's Economy and Development Co-Op. It meets the WRAN standards because it uses the same meteorological equipment. It has 2 Anemometers and 1 Vane at 50-meters as well as a temperature sensor near ground level. Gettysburg does not have wind measuring sensors at the 70-meter or 90-meter elevations. It also does not use a pyranometer to measure solar irradiance.
• Murdo includes the equipment from the above 2001 WRAN sites. In adition to earlier WRAN towers, Murdo is also equipped with 2 anemometers and 1 vane at 90-meters
• Medicine Butte Ridgeline and Belle Fourche sites are both privately owned. They are instrumented the same as the Gettysburg sige

The 2007 sites are owned by South Dakota. They have been placed on Public Broadcasting Towers near the towns of Faith and Martin.

• Both towers measure wind speed and direction at 50, 70 and 90 meters height
• 2 anemometers and 1 vane have been placed at each level
• 1 pyranometer, 1 temperature sensor and 1 datalogger will be placed near ground level

Data from the site will be collected by South Dakota State University's State (SDSU) State Climate Office (SCO) and will be made available to the public via this website.

What is the purpose of the WRAN?

There are several reasons why the WRAN was built. One of the most obvious is that it will allow statistical verification of the existing resource assessments of our state. South Dakota has tremendous potential as an exporter of wind-generated electricity. There has recently been a great deal of publicity over a Pacific Northwest National Laboratories study conducted in the early 1990s that ranked the contiguous 48 states in terms of their potential to produce wind power. (Click here for the results of this study as given by the American Wind Energy Association.) South Dakota ranked fourth in that study. Also, more recently, detailed maps of the wind resource in South Dakota were produced by the National Renewable Energy Laboratory (NREL). Unfortunately, both of these studies had to rely heavily on computer-generated models and very sparse measured data, because very little appropriate measured data exists. The WRAN will provide valuable data that we anticipate will validate the NREL maps, and perhaps suggest minor adjustments.

There are many other benefits the WRAN will provide. The data it will measure will be at heights above ground that are more appropriate for predicting the performance of large modern wind turbines, as opposed to data collected at National Weather Service stations whose anemometers are usually only about 9 m (30 feet) above ground. Also, we will collect some different types of data than most wind measurement networks, which will allow a series of important studies of the potential impact and value of South Dakota's wind power. (For more information on these studies or types of data, contact Dr. Dennis Todey. In addition, all of the WRAN data will be made available to the public via this internet site. This will hopefully enable extensive informed discussion among all South Dakotans on such important
topics as rural economic development and transmission system expansion.

Who is responsible for WRAN?

Wind Powering America: The WRAN was made possible by a grant from the Department of Energy through its Wind Powering America project, and by a grant from the South Dakota Governor's Office of Economic Development.

East River Electric Cooperative: The 2001 installation sites, communications network airtime, and installation assistance were generously donated by East River Electric Cooperative of Madison, SD.

West Central Electric Cooperative: The Murdo site is sponsored by West Central Electric Cooperative.

Gettysburg-Whitlock Bay Economic Development Corporation: Gettysburg site was installed and had been maintained by the Gettysburg-Whitlock Bay Economic Development Corporation. Unfortunately the WRAN project has not received data from the Gettysburg
tower since late last year.

Kennebec Telephone: An independent land owner, Warren Karlen and his brother Brad funded their own tower on Medicine Butte Ridgeline, which is north of Kennebec and Reliance, SD. They had a local company, Kennebec Telephone, install
the tower and instrumentation.

Black Hills Corporation: Another new site near Belle Fourche is being sponsored by the Black Hills Corporation. They have been extremely generous and an integral part of funding some of the WRAN. The Black Hills Corporation also installed and continues to maintain the Belle Fourche

Contact Information:

The head of the WRAN project is Dr. Dennis Todey of the Agricultural Engineering Department. For further information on this project, please contact him.

To the greatest extent possible (within the constraints of our use of existing towers and resources), we are conducting this wind assessment program in accordance with the guidelines laid out in the 1997 Wind Resource Assessment Handbook (National Renewable Energy Laboratories and AWS Scientific, Inc.).