The table in this article shows basic specifications for small wind turbines available and supported in North America. Understanding the specs will help you make intelligent turbine-buying choices.
The manufacturer indicates the source of the wind turbines listed, either manufactured in North America or imported.
Swept area is the area in square feet of the rotor. This is the “wind collector” area, and besides average wind speed, is the biggest factor influencing turbine output. A larger rotor will capture more energy.
Warranty is noted in years, but we urge you to find out what is covered and what is not. Usually it only covers the equipment, not the replacement labor costs and shipping, which can be significant. Several manufacturers also offer extended warranties for an additional cost.
SWCC status refers to the Small Wind Certification Council (SWCC), an independent certification body, which certifies that small wind turbines meet or exceed the requirements of the AWEA Small Wind Turbine Performance and Safety Standard. This certification provides a common North American standard for reporting turbine energy and sound-level performance. The table notes whether the manufacturer has applied for certification with the SWCC, but not the status of the application or how far along the testing is. Turbine certification will likely be required to qualify for some states’ financial incentives. Since these agencies typically fund only grid-tied systems, manufacturers are unlikely to apply for certification for off-grid systems, which are usually the “smaller” small turbines.
While only a handful of manufacturers are in the process of SWCC certification, other companies may be pursuing certification from other agencies. For example, there are several certification bodies in Europe, and many of the turbines listed are manufactured there. In addition, other organizations in other parts of the world offer various types of certification for turbines or turbine components. However, since public benefits programs will likely rely on SWCC certification, this is the certification status to keep an eye on.
Predicted annual energy output (AEO) at hub height at average wind speed shows manufacturers’ projected production for that turbine at wind speeds from 8 through 14 mph. These present some general numbers to match to your site’s average wind speed and your energy needs. All of the AEOs provided in the table were supplied by the manufacturers. Your turbine’s performance on your site may vary, sometimes significantly. You may want to derate the listed AEOs by about 25%. We have no evidence that all manufacturer AEOs are overstated, although some seem to be. It is certainly better to underpredict AEO, and be pleasantly surprised, than to overpredict and be disappointed.
For installer evaluations of the manufacturers and their equipment, 65 installers who are active and earning a living in the small wind industry were sent surveys. Using an “A to F” convention, installers were asked to “grade” the turbines and the level of service that the manufacturers provide. The table includes the average of their responses to questions, which included:
- Manufacturer’s pre-sales response to product questions
- Overall quality of the product
- Completeness of order
- Post-sales technical support
- Reliability of system
We also asked installers to answer “Yes” or “No” to the following questions:
- Would you sell or install this turbine to another customer?
- Would you buy and install this turbine for yourself?