100 kW turbine at Hyannis Country Garden
Are you a business or community interested in installing a wind turbine?
Cities, towns, schools, wastewater districts, and businesses across Massachusetts are considering wind power, not only because it is one of the cleanest, lowest impact sources of electricity available to us today, but also because a properly sited and well managed wind power project can be a net source of income. Below are some of the major factors to consider in determining whether you can beneﬁt from wind power.
There are a number of issues one must consider when contemplating wind (see the guides and fact sheets under the Learn about Wind Energy section).
The primary issue is determining a viable site. Unlike conventional power plants, where a wind turbine is located has a major effect on the amount of energy captured from the wind and electricity produced. The quality of a wind site depends on many factors including:
Wind speed — This is the most critical site characteristic and, of course, some places have more wind than others. Typically, locations with an annual average wind speeds above about 6 m/s (13 mph) at the hub height are considered. While wind maps may not accurately represent a speciﬁc site they are a useful screening tool to estimate the wind speed in an area and therefore a good place to start. Two helpful sites are AWS Truewind and 3Tier. Both require log-in but are free (or have free options). Or, give the Wind Energy Center a call (413 545 3914) and we can prepare a quick wind resource map for your site.
Topography, accessibility — The site should be open and generally at a higher elevation than the surrounding area. Steep hills or cliffs can create turbulence and should be avoided. However, gradually sloping hills can actually cause an increase in wind speed at the top. The topography of a site must also allow access roads to be built for construction and maintenance equipment.
Distance to transmission lines and loads — Electricity generated by a wind turbine must be fed into the electrical grid. Building new transmission lines to move electricity to where it is needed can be very costly, so sites near existing power lines reduce this expense.
Surface roughness — Tall obstacles on the Earth’s surface like trees and buildings can signiﬁcantly slow the speed of the wind and create turbulence. Turbulence reduces the amount of energy that can be captured and can increase maintenance costs over time. Siting turbines in open ﬁelds or in the ocean reduces the effect of surface roughness. Taller towers can also be used to get the rotor above the turbulent zone.
Environmental considerations — Wind power’s predominantly positive environmental impacts do not eliminate the need to consider the local environmental effects of an installation. The National Wind Coordinating Committee is a consortium of experts addressing these issues, which include:
Visual impacts — Wind turbines are large structures and are usually built in open areas or on ridgelines, making them visible from a distance. Some people simply do not like looking at wind turbines. This can be especially true in historically important areas or in places valued for their natural beauty. Siting turbines away from these areas can minimize this impact. Visual impacts include views and visual flicker effects on sunny days when the sun is at certain angles.
Sound impacts — While noise from wind turbines is minimal, at sites very close to population centers and residences it can become an issue. At present there are some limits to how much a new development can increase the sound level, but standards are evolving. Again, siting turbines away from population centers will reduce this impact.
Birds and bats — Sites that lie in bird migration paths or have endangered species in the area may not be appropriate for wind power.
Most projects will require environmental impact studies reviewing visual and noise impacts, potential effects on wildlife and wetlands, and an FAA determination of "no hazard" if the project is near any airports.