Community Wind Handbook/Conduct a Wind Resource Estimate
Conduct a Wind Resource Estimate
Multiple tools are available to help you delve further into the resource assessment of a particular site to ensure that the project lives up to its full potential. As a first step, you can consult a wind resource map, which is used to estimate the wind resource in your area. The U.S. Department of Energy provides high-resolution wind resource maps by state at a 30-meter (m) height. The actual wind resource on your site will vary depending on topography and structure interference, but these maps provide a good place to start. Localized sites with good winds, such as a ridge top, may not appear on the maps.
Small wind site assessors can help you determine whether you have a good wind resource on your site. State or utility incentive programs may be able to refer you to site assessors trained to assess the wind resource at specific sites. Computer programs that estimate the wind resource at a particular site with specific obstacles are also available. Site assessors and computer programs can help to refine the estimates provided on wind resource maps.
Although there may be many methodologies for understanding the wind resource at a specific location, gathering on-site, measured wind data is typically preferred.
Direct monitoring by a wind resource measurement system at a site provides the most accurate picture of the available resource, but at a cost. Wind measurement systems are available; whether this expense is justified depends on the nature of the proposed small wind turbine system and its costs. Systems can be purchased for as low as $600 to $1,200. Whether you should conduct direct monitoring for a small community wind installation depends on the uncertainty and risk regarding the project. Experts have suggested that the cost becomes more justifiable for systems 50 kilowatts and above.
The measurement equipment must be placed high enough to avoid turbulence created by trees, buildings, and other obstructions. The most useful readings are those taken at hub height.
Computer modeling can be used to extrapolate wind conditions at a specific site based on historical data. Often computer models of a site’s resource can be less expensive than conducting direct monitoring for a year or more.
Long-term reference points, like an airport or weather station, can also be beneficial in assessing the wind resource in your area. The data from these reference points can help determine the inter-annual variability of the wind in the area.
If there is a small wind turbine in your area, you can contact the owner of the system to ask whether you can access any information on the annual output of the system and any available wind speed data.
- "U.S. Department of Energy. Frequently Asked Questions on Small Wind Systems"
- "U.S. Department of Energy. Planning a Small Wind Electric System"
- "U.S. Department of Energy. Small Wind Site Assessment: Wind Powering America Lessons Learned"
- "Windustry. Wind Resource Assessment"
- "AWS Scientific for the National Renewable Energy Laboratory. Wind Resource Assessment Handbook"