Wind Energy FAQ

What are wind turbines made of? How much does a wind system cost? I've heard about a new small wind turbine that starts up and runs at very low wind speeds. Is that a new Idea? What is the standard payback period? Will it help the environment if I install a wind turbine at my home? How do I get a permit to install a turbine? Do wind turbines frighten livestock? How do residential wind turbines work? Why don't they make turbines that look like old fashioned windmills? What size turbine do I need for my home? Will a small wind turbine save me money? Are there any rebate or incentive programs available where I live? What about towers? How many turbines are needed to power a household or farm? Is there anything I should watch out for when buying a small wind turbine? What is a "Vertical-Axis" wind turbine, or "VAWT"? How reliable are wind turbines? Will I have to perform much maintenance? Will my utility allow me to hook up a wind generator? Will my local government allow me to install a wind turbine? Can I power my whole house with a wind turbine? How do small wind turbines compare with other renewable energy technologies suitable for decentralized rural electrification? Can I mount the turbine on my roof? Do wind turbines make noise or interfere with TV reception? How much wind potential does my site have? Do small wind turbines kill birds? Are small wind turbines safe? Aren't wind turbines too "high-tech" for regular people?

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What are wind turbines made of?

The towers are mostly tubular and made of steel, generally painted light grey. The blades are made of glass-fibre reinforced polyester or wood-epoxy. They are light grey because this is the colour which is most inconspicuous under most lighting conditions. The finish is matt, to reduce reflected light. (Courtsey of bwea.com)

How much does a wind system cost?

Small wind energy systems cost from $3,000 to $6,000 for every kilowatt of generating capacity, or about $40,000 for a system (installed) large enough to power most of a home. This is much cheaper than solar systems, but the payback period can still be lengthy – as little as 6 but up to 30 years. That's why it's important to take advantage of rebates or tax credits available for small wind system installations. Well-sited small wind turbines can usually pay for themselves within 15 years, about half their serviceable lifetimes, if the right incentives are applied. (Courtesy of AWEA.com)

I've heard about a new small wind turbine that starts up and runs at very low wind speeds. Is that a new Idea?

No. Many inventors have developed turbines that run at low wind speeds. But because the energy available in the wind is a function of the cube of its speed, there is very little energy available to be harvested at wind speeds less than 4 meters per second (m/s) (9 mph). If you are considering the purchase of a small wind turbine, the ability to run at low wind speeds should not be an important factor in selecting a machine.(Courtesy of AWEA.com)

What is the standard payback period?

Each installation site will be unique with variables such as site wind profiles, topography, type of storage, height of the tower, and type and size of wind turbine installed. In addition, return on investment calculations seldom figure in the increasing cost of utility or fuel charges over time. Therefore, any standard payback period would at best be only an estimate. So, consider more importantly the life cycle of your installation. Once installed, your utitlity or fuel costs to run a turbine is ZERO.

Will it help the environment if I install a wind turbine at my home?

Yes. Wind turbines produce no air, water, or thermal pollution and emit no greenhouse or smog-causing gases. By using wind power you will also 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 gas pollutants (carbon dioxide and other gases which cause global warming). (Courtesy of AWEA.com)

How do I get a permit to install a turbine?

A building permit will be required to install your wind turbine system. You will need to contact your local building department to determine if they have established regulations for wind turbines. Many departments do not have wind turbine regulations established (this should change in time as wind turbines become more prevalent). Therefore, you may need to apply for a zoning variance at a public hearing with your local planning board. It would be wise to seek the support of your neighbors before the hearing if you are installing in a residential area. Permitting fees could range from a couple hundred dollars to over a thousand dollars depending on where you live. We can provide the support to help you through this process. (Courtesy of Brightideas.com)

Do wind turbines frighten livestock?

Wind farming is popular with farmers, because their land can continue to be used for growing crops or grazing livestock. Sheep, cows and horses are not disturbed by wind turbines. (Courtesy of Bwea.com)

How do residential wind turbines work?

A wind turbine, which is installed on top of a tall tower, collects kinetic (motion) 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) – the minimum speed to spin the blades - 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, many utilities institute a policy called “net metering” whereby the extra electricity is sold back to the utility. All of this is done automatically. There are no batteries in a modern, grid-connected residential wind system. Small wind systems for remote (off-grid) applications operate somewhat differently and often charge batteries so electricity is available when the wind isn’t blowing. (Courtesy of AWEA.com)

Why don't they make turbines that look like old fashioned windmills?

The old fashioned windmill is viewed with nostalgia, and some people prefer the look of them to that of their modern counterparts. Just because wind turbines are modern, it doesn't mean they won't look just as good over time. A modern wind turbine is simply an improved windmill. Every aspect of their design has been optimised, making them far more efficient than old style windmills at generating electricity. To make them look more old-fashioned would just result in more expensive electricity. (Courtesy of bwea.com)

What size turbine do I need for my home?

Homes use approximately 10,000 kilowatt-hours (kWh) of electricity per year (about 830 kWh per month), though this amount can vary considerably. An air-conditioned home in Arizona , for example, will use more electricity than a non-air - conditioned home in Vermont. Depending upon the average wind speed in the area, a wind turbine rated in the range of 5 to 10 kilowatts would be required to make a significant contribution to meet this demand. (Courtesy of AWEA.com)

Will a small wind turbine save me money?

A wind turbine typically lowers a household electricity bill by 50% to 90%. 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. Depending on the turbine size and the installation site, a turbine could supply more than 100% of a home’s energy needs, sometimes resulting in a “negative” electric utility bill. In northern parts of the U.S. where less air conditioning is used, electricity 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. Since energy conservation is usually less expensive than energy production, making your house or farm more energy-efficient first will likely reduce the amount of investment in a wind system to meet your needs. Most wind system purchasers have done all the reasonable efficiency measures first. (Courtesy of AWEA.com)

Are there any rebate or incentive programs available where I live?

For the most up-to-date listing of incentives, policies, and regulations at the state and federal levels, see the Database of State Incentives for Renewables & Efficiency at http://dsireusa.org (Courtesy of AWEA.com)

What about towers?

The taller the tower, the better. 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 speed increases with height above ground, and increasing speed increases wind power exponentially. Thus, relatively small investments in increased tower height can yield very high rates of return in power production. For instance, installing a 10-kW generator on a 100-foot tower rather than a 60-foot tower involves a 10% increase in overall system cost but can result in 29% more power. Taller towers also raise blades above air turbulence, allowing the turbines to produce more power. A rule of thumb for proper and efficient operation of a wind turbine is that the bottom of the turbine's blades should be at least 30 feet above the top of anything within 500 feet. Also be aware of any height restrictions your local zoning rules may impose. Occasionally local rules prohibit structures higher than 30 feet or so. 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. (Courtesy of AWEA.com)

How many turbines are needed to power a household or farm?

For a home or farm, one turbine with a power rating of anywhere from 1kW to 25kW is normally installed. The turbine's size is chosen to meet the energy requirements given the available wind resource. Buying multiple turbines for one application rather than a single larger one is almost always less economical because of the cost of buying two separate towers and installing two separate systems. For village electrification applications, both single and multiple turbine installations are common, and turbines up to 100 kW in capacity may be used.(Courtesy of AWEA.com)

Is there anything I should watch out for when buying a small wind turbine?

"If it seems too good to be true, it probably is" are words to keep in mind when shopping for a small wind turbine. Over the years, a steady stream of "breakthrough"wind turbines has promised exceptional performance at an incredibly low price. Sometimes the claimed performance violates the laws of physics, promising more power than the total kinetic energy available in the windstream that is intercepted by the rotor's swept area. These often well-meaning entrepreneurs usually do not have the engineering background to perform proper calculations and tests. There have also been out-and-out frauds in the wind business where the entrepreneur set out to intentionally defraud the public, particularly from overseas manufacturers. This has been possible, at least in the short term, because most people aren't experts on the physics of wind energy, and they have a hard time sorting out reasonable claims from unreasonable ones. Who wouldn't be tempted to buy a new wind turbine "twice as efficient as anything on the market"? Most of the popular models of small wind turbines operate at about the same efficiency. The energy production you should expect will be closely related to the swept area of the rotor blades, which is based on the diameter of the rotor. If you are offered a product that promises to run your whole house with a turbine that is much smaller than conventional products, it's time to start asking hard questions. Another way to protect yourself is to make sure that the dealer who sold you the wind turbine can provide references from prior satisfied customers. (Courtesy of AWEA.com)

What is a "Vertical-Axis" wind turbine, or "VAWT"?

The vast majority of wind turbines are three-bladed, “propeller-shaped” devices that spin around an axis that is parallel – or horizontal – to the ground. These are called “horizontal-axis wind turbines,” or “HAWTs.” An alternative system configuration features a rotor that revolves around an axis that is perpendicular – or vertical – to the ground, similar to a barbershop pole or corkscrew.(Courtesy of AWEA.com)

How reliable are wind turbines? Will I have to perform much maintenance?

Most small turbines have only 2-3 moving parts and are designed for a long life (20 - 30 years). However, as with any other hard-working machine, parts must be maintained and occasionally repaired. The average residential-sized wind turbine will put on as many "miles" in just four months as the average car does in its 100,000-mile lifetime. No responsible automobile owner would expect their car to perform for such an extended period of time with no tune-ups or oil changes, let alone without maintenance.(Courtesy of AWEA.com)

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 wind energy systems. A wind turbine manufacturer should be able to help arrange the required utility company approvals. (Courtesy of AWEA.com)

Will my local government allow me to install a wind turbine?

A wind turbine is a tall structure that normally requires a building permit. Zoning regulations often limit the height, placement, and other characteristics of "appurtenant" structures, so a conditional (special) use permit or variance may be necessary. It's usually best to let your neighbors know about your installation ahead of time. Be prepared to answer questions and clear up common misconceptions with well-documented facts about small wind turbines. (Courtesy of AWEA.com)

Can I power my whole house with a wind turbine?

Many factors will determine your ability to power your whole house: What is the wind resource available at the site? How much power do you consume? Do you utilize a storage medium for low consumption periods? Does your utility allow for grid connected net-metering? Are you willing to utilize low power consuming technologies such as LED lighting? We all know the wind does not blow all the time. If your goal is to reduce your utility consumption to near zero, we typically recommend a hybrid system combining wind with available solar, geothermal, or hydro. (courtesy of Brightideas.com)

How do small wind turbines compare with other renewable energy technologies suitable for decentralized rural electrification?

Wind power is very competitive with solar photovoltaics (PV), biomass, and diesel generators, but is usually more expensive than micro-hydro. Wind is also very attractive for the ease with which the technology can be transferred to developing countries. Generally speaking, wind power complements these other power sources by providing a least cost approach under certain conditions. This expands the range of potential projects, pointing to the day when decentralized electrification projects will be implemented on the same scale as current utility line extension projects. In many situations, the lowest-cost centralized system will be a hybrid system that combines wind, photovoltaics, and diesel.(Courtesy of AWEA.com)

Can I mount the turbine on my roof?

The GUS vertical axis turbines by Tangarie may be mounted on a roof with some structural considerations and potentially added cost. However this would not be the best option for siting to produce the most power from the available resource. It is best to get the turbine as high as possible, and in a location with the fewest obstructions to the wind to maximize power yield. And more often than not, this would be away from the rooftop, and on a pole. The horizontal axis turbines by ReDriven are not mounted on a roof and are typically mounted on a hydraulic concrete pole. The ReDriven hydraulic pole is unique in that it allows the turbine to be lowered to the ground for servicing or to better protect the turbine in advance of extreme weather conditions. (Courtesy of Brightideas.com)

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. Small wind turbines do not interfere with TV reception. (Courtesy of AWEA.com)

How much wind potential does my site have?

General wind classifications for your area can be found at the Department of Energy website. Local meterological stations can also provide wind data for your area. Due to site conditions such as elevation, height of surrounding trees and buildings, you may want a specific wind study for your site. We can provide you with monitoring services for a fee, or you may purchase your own monitoring equipment. (Courtesy of Brightideas.com)

Do small wind turbines kill birds?

While no such studies have been performed specifically for small wind turbines, anecdotal evidence indicates that birds occasionally collide with small wind turbines as they do with any other type of structure. However, such events are rare and very unlikely to have any impact on bird populations. Large, utility-scale wind turbines account for less than 0. 0 03% of all human-caused bird deaths, and small wind turbines have even less of an impact. House cats in the U.S., by contrast, are estimated to kill roughly one billion birds each year. Statistically, a single house cat, a window pane, or an automobile is a much greater threat to birds than a wind turbine of any size. (Courtesy of AWEA.com)

Are small wind turbines safe?

Yes. However, neighbors who are uneasy about a nearby homeowner installing a small wind turbine may raise all sorts of questions about safety. Brief answers to some of these concerns: Falling tower: Thousands of wind turbines are installed in the U.S., and their safety track record is excellent. Trees are much more likely to fall than a properly installed wind turbine, but no setbacks or minimum property sizes are required for trees. Safety of utility repair personnel during a power outage: Small wind systems shut down automatically in the event of a power outage to protect utility workers, and will not energize a dead power line. Ice throw from rotor blades: Ice buildup makes wind turbine blades heavier and less aerodynamic, and therefore they turn more slowly. Typically, ice will drop to the base of the turbine tower instead of being thrown. Children climbing the tower and falling: Possible, but wind turbines should be treated no differently than other climbable structures such as water towers or amateur radio antennas. (Courtesy of AWEA.com)

Aren't wind turbines too "high-tech" for regular people?

The high technology of a wind turbine is in just a few manufactured components such as the blades. A wind turbine can actually be much simpler than a diesel engine, and also require substantially less attention and maintenance. Some types of small turbines can operate for extended periods, five years or more, without any attention. With training and spare parts, local users can support the wind turbine equipment they use. (Courtesy of AWEA.com)