How do residential wind turbines work?
A wind turbine, which is installed on top of a tall tower, collects kinetic energy from the wind and converts it to electricity that is compatible with a home's electrical system.
In a normal residential application, a home is served simultaneously by the wind turbine and a local utility. If the wind speeds are below cut-in speed (7-10 mph) there will be no output from the turbine and all of the needed power is purchased from the utility. As wind speeds increase, turbine output increases and the amount of power purchased from the utility is proportionately decreased. When the turbine produces more power than the house needs, the extra electricity is sold to the utility. All of this is done automatically. There are no batteries in a modern residential wind system.
Small wind systems for remote applications operate somewhat differently.
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Will a small wind turbine save me money?
The wind turbine typically lowers your electricity bill by 50 to 90 percent. It is not uncommon for wind turbine owners with total-electric homes to have monthly utility bills of only $8 to $15 for nine months of the year. In northern parts of the country where less air conditioning is used the bills can be very low year-round. The amount of money a small wind turbine saves you in the long run will depend upon its cost, the amount of electricity you use, the average wind speed at your site, and other factors.
What size turbine would I need for my home?
Homes use approximately 9,400 kilowatt-hours (kWh) of electricity per year (about 780 kWh per month). Depending upon the average wind speed in the area, a wind turbine rated in the range of 5 to 15 kilowatts would be required to make a significant contribution to meet this demand.
Who should consider buying a wind turbine?
A residential wind turbine can be a relatively large device and is not suitable for urban or small-lot suburban homes. Except for very small wind turbines (i.e., with rotors one meter or less in diameter) on very small towers, a property size of one acre or more is desirable.
The economics of a wind system are very sensitive to the average wind speed in the area, and to a lesser extent, the cost of purchasing electricity. As a general rule of thumb, if economics are a concern, a turbine owner should have at least a 10 mph average wind speed and be paying at least 10 cents/kWh for electricity.
Residential wind turbines have been installed in at least 47 of the 50 states, but the majority of the units have been installed in the Northeast and the Midwest.
Will it help the environment if I install a wind turbine at my home?
Yes. Wind turbines produce no pollution and by using wind power you will be offsetting pollution that would have been generated by your utility company. Over its life, a small residential wind turbine can offset approximately 1.2 tons of air pollutants and 200 tons of greenhouse gases (carbon dioxide and other gases which cause climate change).
maintenance.
3 comments:
Don't I have to take wind measurements for a year or more?
For most residential systems the cost of taking wind measurements is not justified. Wind resource data published by the U.S. Department of Energy is sufficient for an experienced evaluator to predict wind turbine performance. In very hilly or mountainous areas, however, it may be best to collect wind data before purchasing a system to ensure that your site is not in a sheltered area.
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Do wind turbines make noise or interfere with TV reception?
Small wind turbines do make some noise, but not enough to be found objectionable by most people. A typical residential wind system makes less noise than the average washing machine. Wind turbines do not interfere with TV reception.
Will my utility allow me to hook up a wind generator?
Federal regulations (specifically, the Public Utility Regulatory Policies Act of 1978, or PURPA) require utilities to connect with and purchase power from small (less than 80 MW) wind energy systems. A wind turbine manufacturer should be able to help arrange the required utility company approvals.
See State-by-State small wind information for lists of interconnection requirements for many U.S. states.
Will I have to change any of the wiring in my house?
No. A wind turbine is easily retrofitted to virtually any home without the need to change any wiring or appliances. In most cases, the utility will install a second utility meter to measure how much surplus electricity it is purchasing from the turbine owner.
What about towers?
An 80- to 120-foot tower is usually supplied along with the wind turbine. Towers this tall are necessary to raise the wind turbine above turbulence generated by obstacles on the ground and trees. Wind velocity and, therefore wind turbine performance, increases with altitude. Several different types of towers are available, depending upon which manufacturer you select. Each type has its advantages; the most economical type of tower is the guyed lattice tower, but a hinged tower can be easier for you to install yourself and provides easier access for maintenance.
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How much does a wind system cost?
A small turbine can cost anywhere from $6,000 to $22,000 installed, depending upon size, application and service agreements with the manufacturer.
How reliable are wind turbines? Will I have to perform much maintenance?
Most small turbines have very few moving parts and do not require any regular maintenance. They are designed for a long life (up to 20 years) and operate completely automatically.
How do wind turbines perform as an investment?
The wind system will usually recoup its investment through utility savings within six to 15 years and after that the electricity it produces will be virtually free. Over the long term, a wind turbine is a good investment because a well-sited wind system increases property value, similar to any other home improvement. Many people buy wind systems in preparation for their retirement because they don't want to be subject to unpredictable increases in utility rates.
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How would I have a wind turbine installed at my home?
Most dealers offer either complete turnkey (ready-to-operate) installations or the option to purchase direct from the factory and install the system yourself. The first option offers more customer support from the company. Self-installation offers significant savings and a hands-on understanding of the turbine. Prospective owners can discuss the options available with manufacturers to decide which method best suits their budget and technical skills.
Small wind
Small Wind Turbine Equipment Providers
Important Questions to Ask When Shopping for a Small Wind System
Adapted from the June/July 2009 issue of Home Power Magazine, www.homepower.com, 800-707-6585
Equipment manufacturers or their dealers should be able to answer the following questions about their products (see also www.awea.org/smallwind/faq.html):
What is the energy output (measured in kilowatt-hours or kWh – not in kilowatts or kW) of the turbine, over one year, in average wind speeds of 8 to 14 mph? Is this calculated using real-life ("field") data (preferred), or laboratory / wind tunnel testing?
Can you refer me to other customers who have owned [Model X] for a period of time? (The longer, the better.)
What is the warranty length and coverage (industry standard is 5 years)?
Has the turbine/tower ever gone through a reliability test? By whom? For how long? What were the results?
How long has the company been producing turbines?
How long has [Model X] turbine been available to sale to ordinary customers – not in the prototype or beta testing phase?
For how long was the prototype tested? By whom? In the field or in a laboratory?
How many turbines of [Model X] been sold, and for how many years? How many of these are still running?
How frequently has [Model X] been redesigned? What were those changes and how recent were they?
What problems have other customers encountered and how have you dealt with them?
The American Wind Energy Association (AWEA) has compiled the following list of U.S. manufacturers and suppliers of wind turbines for use in residential, farm, and commercial/industrial applications. Many have Web sites or are accessible through E-mail links. Links are also provided to the company listings on the AWEA Industry Member Directory.
Manufacturer Models (Rated Capacity)
Abundant Renewable Energy
www.abundantre.com ARE110 (2.5KW), ARE442 (10KW)
Aerostar
www.aerostarwind.com Aerostar 6 Meter (10KW)
Aerostar Independence (10-30 kW)
AeroVironment
www.avinc.com AVX-1000 (1kW system)
Bergey Windpower Co.
www.bergey.com BWC XL.1 (1 kW),
BWC EXCEL (10 kW)
Cascade Engineering, Inc.
www.swiftwindturbine.com
SWIFT Wind Turbine (1.0 kW)
Energy Maintenance Service
www.energyms.com E15 (35 kW or 65 kW)
Entegrity Wind Systems
www.entegritywind.com EW50 (50 kW)
Gaia-Wind Ltd
www.gaia-wind.com 11kW
Mariah Power
www.mariahpower.com Windspire (1.2 kW)
Northern Power
www.northernpower.com NPS 100 (100 kW)
Proven Energy, Ltd.
www.provenenergy.co.uk Proven 2.5 (2.5kW), Proven 6 (6kW), Proven 15 (15kW)
ReDriven Power, Inc.
www.redriven.net 2kW 5kW 10kW 20kW
Southwest Windpower Co.
www.windenergy.com AIRX (400 W), Whisper 100
(900 W), Whisper 200 (1 kW), Whisper 500 (3 kW),
Skystream 3.7(1.8 KW)
TechnoSpin Inc.
www.tswind.com PowerSpin TSW 2000 (2KW), ComSpin C 2000 (2KW)
Urban Green Energy
www.urbangreenenergy.com UGE-300 (300W rated capacity),
UGE-1K (1kW rated capacity),
UGE-4K (4kW rated capacity)
Ventera Energy, Inc.
www.venteraenergy.com VT10 (10kW)
WePOWER
www.wepower.us Falcon
1.2kW 3.4kW 5.5kW 12kW
Windvertiser
Wind Energy Solutions Canada
www.windenergysolutions.ca WES 5 Tulipo - (5 Metre Rotor Dia. - 2.5 kW), WES 18 - (18 Metre Rotor Dia. - 80 kW), WES 30 - (30 Metre Rotor Dia. - 250 kW)
Wind Turbine Industries Corp.
www.windturbine.net
23-10 Jacobs (10 kW),
31-20 Jacobs (20 kW)
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