PDF《Small Wind Column》

5 WINDLETTER nancial institution considering a loan for the system, or the state public benefits program or U.S. Department of Ag- riculture (USDA) should a grant application be submitted. These entities will not be privy to what the site looks like, and any photographs will go a long way toward helping them understand what you are planning. Landmines and installation considerations Finally, the assessor will need to assess potential landmines for the installation―that is, services and structures that may be problematic for any installation. For example, where are the septic tank and field? You certainly do not want a backhoe excavating for a tower anchor in your leach field. Nor do you want a crane driving over your septic tank. Other critical questions about the site include: What is the location of the well and any water lines? Is there an underground gas or LP line in the area? What about the existence of underground services such as utility or phone lines? Are there any red flags with respect to your soil type? Do you have critical soils that consist essentially of gravel or muck, neither of which will support a standard tower foundation? Does your property have a high water table, which might impact the foundation design? How deep is the bedrock on the property? (This too may affect the foundation design.) Infrastructure issues What is the capacity of your electrical service? Is your circuit breaker box adequate? What about the utility transformer on the pole at the road―is it adequately sized? Are there any plans for future buildings on the property? Regional concerns Are there any nearby airports or air fields? Where are they located? Does anyone engage in aerial application of pesticides on neighboring fields? Zoning ? Are there any height restrictions in your township or county? What setback restrictions from roads or property lines would apply to the tower? Utility interconnection ? What are the local utility'

s regulations and restrictions on interconnecting the system to the grid? Are there any turbine capacity limitations? ? Is there a requirement for a wind system disconnect switch? If so, is there a specified location for this discon- nect? ? What are the insurance requirements of the utility? Will your insurance company insure the system without charging a substantial premium? Site logistics ? Where is the proposed wire run to terminate? ? Will bedrock interfere with the wire run? ? Is there a secure and environmentally conditioned location for the balance of system components (e.g., controls (Continued from page 4) (Continued on page 6) Small Wind Column Page

6 WINDLETTER and inverter) that has an adequate circuit breaker box? Is there adequate space for all such components? Can the wire run be minimized by siting the turbine close to the controls and inverter without compromising the wind resource or creating more turbulence with ground clutter? Siting logistics ? Is there an elevated area on the property that is relatively close to the location of the balance of system compo- nents that can be utilized to optimize the wind resource? ? Where are the site obstacles and trees relative to the prevailing wind directions? It is important to site the tower upwind of such obstacles to maximize wind speed and minimize turbulence. ? What is the distance and height of the trees in the area (which are usually the tallest obstacles that must be over- come by the tower)? ? What is the planned future use for the location of the tower? Are there any activities or planned structures what will either interfere with the installation or with accessing the tower for future maintenance and repair work? ? Where are any overhead power lines which could pose a danger during installation or while workers and service personnel are on the tower? Installation logistics ? If the tower style chosen is guyed, is there adequate room for the guy cables? ? If a tilt-up tower will be installed, is there sufficient space to lower the tower to the ground, and possibly leave it in that position for periods of time? ? Can a concrete truck access the site to pour the foundation? ? Will a crane be able to access the location to set the tower and turbine in place? ? Will either of these heavy pieces of equipment need to drive over the septic tank or field, or other infrastructure that could be damaged by heavy weight? The final report Once the assessor has collected all of the site information they need, they will create a report that includes: ? The minimum acceptable tower height for the site based on terrain and ground clutter. This should take into ac- count the height that the surrounding trees will attain in the 20-30 year life of the wind system. ? The wind rose for the site that details the seasonal prevailing wind directions and any patterns. This is useful for siting the tower upwind of obstacles to minimize ground drag and turbulence. ? The conservatively estimated wind resource at the site at the minimum tower height specified, as well as an ex- planation about how the average annual wind speed for the site was arrived at. ? A list of several wind turbine models that will, ideally, offset the electrical consumption of the owners. The sug- gested turbines may include systems that are larger than required if growth in consumption is anticipated in the fu- ture of the customer, or smaller than currently required if there are opportunities for savings by incorporating effi- ciency. The proposed project also needs to meet the needs, goals, and budget of the customer. Some clients are inter- ested in only installing a token wind system, more as a statement of values. Others might be limited by local utility restrictions as to the size of turbine they can install. The estimated annual energy output of the suggested turbines, at this location, at the specified tower height and esti- mated wind speed. In the end, this is really the purpose of a wind site assessment―to estimate how much electricity (........