Wind power has been used for thousands of years in the form of windmills and other wind machines. In recent decades, wind energy generators have transformed into many different shapes and sizes. They have become popular with environmentally conscience people and mechanically and electrically inclined individuals such as electricians and engineers. Germany and now Asia are the forerunners in wind turbine design, manufacturing, and use.

Definition

A wind turbine is a "rotary device that extracts energy from the wind. If the mechanical energy is used directly by machinery, such as for pumping water, cutting lumber or grinding stones, the machine is called a windmill. If the mechanical energy is instead converted to electricity, the machine is called a wind generator, wind turbine, wind power unit (WPU), wind energy converter (WEC), or aerogenerator." (Wikipedia)

Uses

Commercial: Large wind turbines (generally 200 to 300 feet tall) used in wind farms are owned by power companies or large organizations, as each one costs about a million dollars. These turbines are often three-bladed and are controlled by computer motors that point them into the wind. These turbines have high tip speeds of over 200 miles per hour, high efficiency, and good reliability. The blades are light-colored, range in length from 65 to 130 ft or more, and rotate at 10 - 22 revolutions per minute. Generator speeds may be regulated or increased through a gear box (more common) or direct drive of an annular generator. Some models operate at constant speed while others use variable-speed turbines that can gather more energy. All turbines have shut-down features to avoid damage at high wind speeds.

Residential: Wind micro-turbines are smaller in size for residential applications. They are generally 7 to 25 feet in diameter and produce electricity at a rate of 900 to 10,000 watts at their tested wind speed. Some units are very lightweight, as in 35 lb, allowing them to respond quickly to minor wind movements and wind gusts, which are typical in cities and towns. They can be easily installed, similar to a TV antenna; however, you probably would want a professional installer of wind turbines or be an electrical engineer or electrician to do it. Manufacturers claim that they are inaudible even a few feet under the turbine.


Benefits and Weaknesses

Pro

• Everlasting, free, and renewable resource
• Doesn’t use or produce pollution or radioactive waste
• Low maintenance—15-25 years without maintenance
• Increase home resale value for residential use
• Protects against energy rate hikes
• Large and small tax grants and incentives
• For residential, relatively inexpensive to purchase, install, and maintain
• Low humming sound or noise

Con

• Can be considered an “eye sore”
• Can be damaged by thunderstorms
• Birds can die flying into them (mainly commercial)
• Low humming sound or noise (usually quiet, but some people may dislike)
• Should be installed by a wind power professional and/or someone who is electrically & mechanically inclined such as an electrician or electrical engineer.
• Need to know interconnection, permit, and zoning laws for your area
• For commercial use, high initial cost of about a million dollars per wind turbine

Feasibility

The feasibility and cost-effectiveness to integrate a small wind system at your home or business varies widely, but can often be reasonable. Additionally, some small wind tax credits and deductions exist to help defray costs. However, some things that you should know BEFORE buying a system:

• Interconnection Laws: They vary by country, state, province, municipality, etc… so talk with your power company about that. Other things to know are:
  • Check that you have an adequate resource of wind for a wind turbine
  • Understand the interconnection standards that apply, especially if you want to connect to a grid system.
• Zoning, Planning Board, HOA Rules: Know what is accepted in your area, neighborhood, and associations.