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Best Practices for Siting Small Wind Turbines
Refer to a model ordinance for help in creating a sensible permitting process.
By MICk SAGRIllO
Mick Sagrillo, a small-wind consultant, owns
Sagrillo Power & Light
and is wind energy
specialist for Focus on
him at msagrillo@
Reasonable zoning and permitting regulations are necessary to protect the interests of the applicant and the concerns of neighbors while fostering
responsible wind installations. One of the best small-wind
model zoning ordinances available was developed by
Wisconsin and is available at renewwisconsin.org/wind/
SE TH MASIA
The trick with extremely
tall towers is assessing
the increased cost of the
tower versus the incremen-
tal increase in electrical
Good exposure to the fuel. Any serious inquiry about a
small wind system begins with a trained site assessor visiting
the location to evaluate the client’s needs and energy usage,
as well as the site’s wind potential. One critical item that
needs to be established is the minimum acceptable tower
height for the site. This is solely dependent upon the ground
clutter in the surrounding area. Every effective wind turbine
must be sited on a tower that substantially clears the trees
in the area, not just on the day of the site visit, but for the
20- to 30-year life of the system.
Accordingly, minimum tower height takes into consideration the mature height of surrounding trees and any
future building plans. The rule of thumb for tower height:
The entire rotor of the wind turbine must be at least 30
feet above the mature trees in order to access the free flow
of wind, the turbine’s fuel. Anything lower will compromise both the system’s kilowatt-hour production and its
life expectancy. If the wind is turbulent after spilling over
treetops, it creates wear and tear on the turbine.
This minimum tower height rule is irrespective of turbine or rotor technology — the rule is about the fuel, not
the wind equipment. Keep in mind that the rule specifies
minimum tower height, not optimum height. A taller tower
will always result in increased kilowatt-hour production
because it reaches stronger winds. The trick with extremely
tall towers is assessing the increased cost of the tower versus
the incremental increase in electrical production. A seasoned wind site assessor or honest installer will be able to
deliver these numbers for the client to digest.
Proper setbacks and turbine placement. The need
to access the best and strongest winds dictates that tower
placement should be on the highest ground on the property, with the best exposure to prevailing winds, while maxi-mizing;distance;from;obstacles.;But;the;siting;process;also
height of the structure from property lines, roads and overhead utility lines.
More important than setbacks is proximity to neighbors.
A neighbor may wish to have a wind turbine sited farther
from a home or property line, and that may not allow ideal
siting for power production. This compromised site may
even be lower in elevation or experience inferior access to
the wind than the preferred site. However, buying a slightly
taller tower or a slightly longer wire run to appease the
neighbor, while more costly, may be far cheaper than the
grief created by forcing the project at the optimal location.
Remember, you are going to live with the wind turbine for
20 to 30 years, but you also have to live with your neighbors.
Parallel to good zoning ordinances
are best practices for the installation
of small wind systems.
Paperwork in order. By all means, before plunking any
money down on a wind system — even a down payment
— make sure two important documents have either been
secured or are in process. These are the building permit
for the system and the grid-interconnection requirements
incorporated into any pertinent contract with the utility
company. Without both, the wind turbine simply cannot be
installed and commissioned. Circumventing either permit
will invariably lead to a costly and time-consuming process.
It’s always better to have both the planning department and
the utility company working with you.
Another good idea is to check with your insurance company about the premium to cover the wind system. Most
insurance companies have at least some experience with
wind turbines, and most will quote reasonable rates, but
this is certainly not universal. There are companies that have
never insured a wind turbine and may therefore view yours
as a substantial risk with a commensurate premium. Again,
you need to know this before the system is purchased and
installed. A good wind installer will know of companies willing to insure the system for a reasonable amount of money.
Whether you are a prospective wind turbine owner or a
small-wind installer, making sure that these three steps are
adequately addressed will go a long way toward assuring a
successful wind installation. ST