Frequently Asked Questions

How were the wind maps for the Wind Explorer generated and validated?
What is the accuracy of the wind maps?
Is this application available for other states?
Where can I access wind resource data for other states?
Can I enter turbines that are not included on the Saint Francis list?
What power curves were used in the program?
How is the wind speed frequency distribution calculated?

User Interface and General

How were the wind maps for the Wind Explorer generated and validated?

The wind map displayed in the Saint Francis Wind Explorer was created with AWS Truepower’s MesoMap® system, which is well known in the wind industry as the technology behind ground-breaking wind maps published for the United States as well as many other countries.

MesoMap is a combination of mesoscale and microscale atmospheric models. The mesoscale model simulates weather conditions for a representative meteorological year on a horizontal grid of 2.5 km. Starting from an initial condition established by regional weather data and using the complete set of physical equations governing the atmosphere, the model simulates the evolution of weather conditions from the start to end of each day in the representative year. The microscale model then refines the wind fields from the mesoscale model to capture the local influences of topography and surface roughness changes at a high resolution of 200 m.

The wind map and associated data are fine-tuned using the best available surface observations including Automated Surface Observation Systems (ASOS), tall towers instrumented for wind resource assessment, as well as AWS Truepower's knowledge of local wind regimes.

What is the accuracy of the wind maps?

To produce a true estimate of the map accuracy for the wind map, each station was withheld from the fine-tuning procedure and the difference between the map speed and the observed speed at that station was determined.

With this objective procedure, the standard error (after accounting for uncertainty in the data) is 0.35 m/s (0.8 mph). The standard error is the standard deviation of the map errors at the wind-monitoring stations used in the fine-tuning procedure. Assuming these stations are representative of all locations in the wind map and that the errors are normally distributed (follow a bell curve), the true mean speed should be within the standard error of the map speed in 68% of the mapped area.

The error margin may vary; however, depending on nearby obstructions, the complexity of the terrain and surface conditions and on the density and quality of wind-monitoring stations in the surrounding region. However, in all cases AWS Truepower recommends that the wind resource be measured on-site to confirm the stated wind resource.

Is this application available for other states?

Yes, the Wind Explorer application is available to state agencies and other interested parties as a tool to promote and facilitate responsible small wind development. The site can be customized to include an organization’s branding and tools to support wind program requirements. For more information regarding about this application and pricing please contact AWS Truepower.

Where can I access wind resource data for other states?

Data for other states is available through the AWS Truepower Dashboards.

Can I enter turbines that are not included on the Saint Francis list?

Turbines not included for reports in the Wind Explorer list can be added by contacting us with the turbine information.

Report

What power curves were used in the program?

The Saint Francis Wind Explorer uses power curves obtained from the manufacturer websites.

How is the wind speed frequency distribution calculated?

The wind speed frequency distribution is assumed to be a Weibull distribution defined by a location specific shape and scale parameter and adjusted to the given height. The Weibull distribution is modeled using the following equation within the Wind Explorer application:

Where: p(U) = Probability wind speed will be between U and U+1 (in m/s)
k = Weibull scale factor
c = Weibull shape factor.

Additional Questions

For answers to additional questions please contact us.