Five windmills on a hilly landscape.

Wind is an inexhaustible source of power that provides cleaner energy. Wind turbines are used to turn the kinetic energy of the wind into electrical energy that can be harnessed and placed onto a power grid. There are two different kinds of wind turbines: horizontal and vertical. Horizontal turbines are the most common and are what most people picture when wind power is mentioned. For a time, the only vertical axis wind turbine that was manufactured commercially was the Darrieus machine which somewhat resembled an egg beater. 

Turbines Today

Today, many variations of the vertical axis wind turbine are commercially available. Vertical axis turbines have the advantage of being mounted directly on a structure (building) or on a relatively short tower, but the drawback is that wind speed at ground level is lower than at elevated heights. Horizontal wind turbines however are typically mounted on towers where wind speed is higher and more regular. The wind turbines are made up of four parts: a rotor or blades, a nacelle (includes a drive train, a generator, and a gearbox), a tower, and electrical equipment (cables, ground support, and interconnection equipment). The towers are typically made of steel and the blades are made of fiberglass-reinforced polyester or other light weight composite materials.


Implementing a Turbine

When considering the implementation of a wind turbine within a community, there are some zoning restrictions that have to be taken into account. Some of these include: height limitations, allowable noise, setbacks, maximum rated capacity, and compliance with building and electrical codes as well as FAA regulations. There is also the issue of mounting the turbine. Typically a turbine is mounted on either the ground or a rooftop. Mounting a turbine on a roof or structure requires special design considerations to compensate for and prevent damage to the structure from vibrations when the turbine is active.

What Wind Power Does

The power that is generated from wind turbines is measured in watts and the amount of power that can be produced is dependent on the size of the turbine as well as wind speed. Wind power produced in the United States already provides sustainable energy to more than 4.5 million average households. However, there are some drawbacks to relying solely on wind power. If wind is to ever become the major source of electricity it would be necessary to incorporate a back-up system with the ability to provide the same amount of power during periods of reduced wind. That said, wind power has both environmental and economic benefits. While wind is a renewable resource, it is also a fuel free source so it is generally not affected by inflation.

More Information

For information about average regional wind speed please visit American Wind Energy Association (AWEA) or the U.S Department of Energy, Wind Power America website for wind maps. AWEA also publishes a free Wind Energy Siting Handbook target at large wind projects, however the document provides useful information even for small wind energy systems.

Vendor List

MaineStream Energy Alternatives, Inc.
dba/Saco Solar Store
Route 1, 743 Portland Road
Saco, ME 04072
Phone: 207-283-1413
Fax: 207-283-1414
Cell: 207-229-1411


  • American Wind Energy Association. 2008. Utility. Accessed July 2008.
  • Danish Wind Industry Association. 2003 July 23. Wind Turbines: Horizontal or Vertical Axis Machines? Accessed August 2008.
  • Power of Wind. 2007. Wind Energy 101. Accessed June 2008.