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4 WINDLETTER Back to the Basics 8: Wind Site Assessments By Mick Sagrillo Last month'

s column (http://www.

awea.org/windletter/100325_AWEA_WL.pdf ) described the best tools that we have today for estimating the wind resource for a small wind turbine, and the need to have a trained wind site assessor evaluate your site and wind resource. This column will lay out the items that should be covered in a thorough wind site assessment for a home, business, farm, or even a school district. Initial contact When you contact a person who does wind site assessments, you need to determine his or her capabilities, and any ties they might have to small turbine manufacturers―however loose those ties may be. For example, many people who have been trained to do wind site assessments (but certainly not all) received their training by attending a work- shop put on by a manufacturer. Such trainings vary considerably in quality, with some adequately covering the all- important topics of wind turbine towers and siting, while others focus far more on simply closing the sale. Training from or association with a manufacturer is not a fatal flaw, but it is good to know if there will be any potential bias. When you'

re going through the process of screening prospective assessors, be sure to quiz your candidates, using the information on best practices for siting a wind system that have been covered in this series of columns. If the asses- sor represents a company that offers one tower size for all sites and applications, look elsewhere, as all you are likely to come away with is an intense sales pitch. The first piece of information that the assessor will require is your annual electricity usage. She will likely ask you about your major appliances and try to identify energy efficiency strategies that make sense in your situation. Keep in mind that it is always cheaper to use energy more efficiently with compact fluorescent lighting and high efficiency appliances than it is to install renewable energy equipment to offset electricity consumed by wasteful appliances. The rule of thumb that is used for small wind systems is that every dollar spent on efficiency saves three dollars in generating capacity. Make sure that you settle on a price for the service, which should include a written report to be delivered to you within a reasonable time after the assessor visits your site. The site visit When the assessor visits, he will want to walk around your premises. He is simply getting the lay of the land, and looking for current and potential future obstacles that will affect the performance of the wind turbine by restricting wind flow. The assessor will also want to know your preferred location for the turbine and tower, as well as the loca- tion of the building where the controls and inverter for the system will be housed. Measurements including the height of the tallest obstacles on the property, usually trees, and their distance from the proposed tower site will be used to determine the minimum acceptable tower height for the location;

those measurements will also help the as- sessor arrive at an estimated average annual wind speed for the site. A good assessor will take pictures of the site in eight or more directions, for two reasons. The first is simply to re- fresh his or her memory when reviewing your site information. The second reason is to include these pictures in the wind site assessment report. It is not unusual for a wind site assessment report to be reviewed by a number of people besides the prospective wind turbine owners, including the permitting or zoning authority, the local utility, any fi- (Continued on page 5) Small Wind Column Page