Build Your Own Wind Turbine

This factsheet was prepared by Hugh Piggott who has written a book on this, available from the Centre for Alternative Technology - in the Wind Energy Books section.

Wind energy is both green and fun, so the idea of building one's own wind turbine is a good one. The following will give you an idea of what is involved and point you toward sources of information on the subject.
A free lunch?

Wind energy on a large scale is now competitive with other sources of electricity on the national grid. However, small domestic-sized wind turbines have not yet reached this point. The wind is free, but small wind turbines are expensive in relation to what they produce, and cannot realistically compete with mains electricity. Building your own machine saves some of the cost, but please do not underestimate the difficulty of the task. If it were easy to save money by using small wind turbines, then they would be a major feature of the landscape by now.
Is my site windy enough?

Most people think they live in a windy place, but in fact most residential locations are not suitable for windpower. Trees and buildings break the force of the wind, and create turbulent gusts which can be very destructive. Open hilltop sites or coastal situations with unobstructed views may be suitable for siting a wind turbine. A very tall tower is helpful, but these are frowned on in the UK. Do not forget the effect your wind turbine may have on neighbours, who may not share your enthusiasm!
What size of wind turbine do I need?

Wind turbines work with thin air, so they need to be large in relation to the power they produce. To power a modern home on a good site, the blades would need to span about 5 metres from tip to tip. This is known as the rotor diameter. With careful conservation of energy a smaller machine may suffice. A rotor diameter of 2 metres might yield about 500 kWh of electricity per year, compared with an average annual household consumption of roughly 4,500 kWh.
What sort of generator should I use?

Most small wind turbines are used for charging batteries, to provide a reliable stand-alone power source where grid power is not available. The obvious choice of generator for self-build is the car alternator. However this has major drawbacks. It must be driven at a high shaft speed (over 2000 rpm) to give full output, so you will need to gear it up or modify it in some way to drive it with rotor blades, which typically only manage a few hundred rpm. This reduces the efficiency. In low windspeeds there is very little power available in the wind, and you need a highly efficient generator to capture it. Most, if not all of the power in light winds will be used up energising the magnetic field in the alternator, so the results are disappointing. Nearly all small commercial wind turbines use purpose-built permanent magnet generators for this reason. The DIY enthusiast can make one too, but this is not simple to do. Or you can reuse a permanent magnet motor as a generator. The generator is the key to success or failure of the project, and by far the hardest part to get right.
Can I make my own blades?

The good news is that yes, many beginners have made very useful wind turbine blades, often carved from wood. Or there are sources where you can buy them ready made. If you plan on making your own, it is well worth doing some research and finding out all you can about it in advance. Not only will this save you from 'reinventing the wheel' but it will also be safer. Safety is an important issue even with the smallest wind turbines. Never underestimate the destructive power of a runaway windmill rotor in a high wind. Make sure that you have built-in protection against all eventualities. Control systems are as important as any other part of the wind turbine.
Where do I start?

There are many sources of information about building your own wind turbine. You will need to use discrimination, as there is as much rubbish written on the subject as there is useful information! Building wind turbines is not easy, but if you succeed, the satisfaction is enormous. Best of luck to you all!

This factsheet was prepared by Hugh Piggott who has written a book on building your own wind turbines, available from the Centre for Alternative Technology - in the Wind Energy Books section.

BWEA has no further information on this or other books; please follow the links above.

For more information try this link for Hugh Piggott's website.

Source:http://www.bwea.com/you/byo.html

Wind turbine plant to expand, add 287 jobs

Siemens Power Generation Inc. plans to create 287 additional jobs with an expansion of its Fort Madison turbine-blade production plant, the company announced this morning. The expansion will more than double employment at the high-tech plant, which currently has 246 workers.

Siemens plans to build a 75,000-square-foot addition to the existing 311,000-square-foot plant and construct a new 125,000-square-foot building and a rail yard to expand production of wind turbine blades. The total cost of the project is expected to exceed $33 million. Construction is expected to be completed by October.

"In less than a year since opening, we are already expanding our facility to increase our ability to competitively serve the growing North American market," said Randy Zwirn, head of Siemens Energy Americas, said in a press release. "The dedication and skills of our work force in the existing manufacturing plant have played an important role in our decision to expand the facility," he added.

The announcement solidifies Iowa's reputation as a U.S. renewable energy leader, Gov. Chet Culver said in a release.

"Our leadership in wind continues to energize Iowa's economy by creating high-quality, green-collar careers," Culver said. "This announcement in Fort Madison is proof that Iowa's leadership in wind energy continues to grow, Iowa's economy is strong and our brightest days are ahead."

The 287 positions are expected to pay an average of $17.14 per hour. State officials said the company has applied for economic development incentive funds.

Source: http://www.businessrecord.com/main.asp?SectionID=4&SubSectionID=8&ArticleID=5735&TM=55644.65

Anatomy and characteristics of the wind generator

A typical small wind generator has rotor that is directly coupled to the generator which produces electricity either at 120/240 volt alternating current for direct domestic use or at 12/24 volt direct current for battery charging. Larger machines generate 3 phase electricity. There is often a tail vane which keeps the rotor orientated into the wind. Some wind-machines have a tail vane which is designed for automatic furling (turning the machine out of the wind) at high wind speeds to prevent damage. Larger machines have pitch controlled blades (the angle at which the blades meet the wind is controlled) which achieve the same function. The tower is of low solidity to prevent wind interference and are often guyed to give support to the tower.


Depending on the circumstances, the distribution of electricity from a wind machine can be carried out in one of various ways. Commonly, larger machines are connected to a grid distribution network. This can be the main national network, in which case electricity can be sold to the electricity utility (providing an agreement can be made between the producer and the grid) when an excess is produced and purchased when the wind is low.

Using the national grid helps provide flexibility to the system and does away with the need for a back-up system when windspeeds are low. Micro-grids distribute electricity to smaller areas, typically a village or town. When wind is used for supplying electricity to such a grid, a diesel generator set is often used as a backup for the periods when windspeeds are low. Alternatively, electricity storage can be used but this is an expensive option. Hybrid systems use a combination of two or more energy sources to provide electricity in all weather conditions. The capital cost for such a system is high but subsequent running costs will be low compared with a pure diesel system.

In areas where households are widely dispersed or where grid costs are prohibitively expensive, battery charging is an option. For people in rural areas a few tens of watts of power are sufficient for providing lighting and a source of power for a radio or television. Batteries can be returned to the charging station occasionally for recharging. This reduces the inconvenience of an intermittent supply due to fluctuating windspeeds. 12 and 24 volt direct current wind generators are commercially available which are suitable for battery charging applications. Smaller turbines (50 -150 watt) are available for individual household connection.

K-12 Energy Lessons plans & activities

On this site you'll find links to more than 350 lesson plans and activities on energy efficiency and renewable energy for grades K-12. Each includes a short summary that identifies curriculum integration, time, materials, and national standards.

http://www.eere.energy.gov/education/lessonplans/

How To: Build Your Own 1000 Watt Wind Turbine

The latest project over at DIY site Instructables (the same place we found Microwave Mitten Warmers) is a 1000 watt wind turbine. Complete with pictures of the construction, from the magnet disks to coils and other necessary parts to a home-made wind turbine, it looks like a work in progress, so we're interested to see how it turns out. For anyone interested in the technical details, it's a permanent magnet alternator, generating three-phase AC, rectified to DC, and fed to a charge controller; if you can't decode the last sentence, beware that this project is for mechanically-inclined DIYers only.

Source: http://www.treehugger.com/files/2006/06/how_to_build_yo_1.php

Homemade Wind Generator

A very useful tutorial for homemade wind generator.

http://www.motherearthnews.com/Renewable-Energy/1981-09-01/The-Wind-Power-Book.aspx

$6 million project to bring solar power to electrical grid

By Bob Klanac
Thursday, February 14, 2008

A groundbreaking project spearheaded by researchers from The University of Western Ontario and the University of Waterloo will enable small solar farms to connect to large electrical grids.
The $6 million project will develop efficient technologies to convert solar energy to electricity and produce weather-predicting software to assist in managing climate challenges. Through these tools, the researchers hope to encourage utilities to adopt solar technologies.

Led by Western and Waterloo researchers, project partners include Hydro One Networks, OptiSolar Farms Canada, Bluewater Power Distribution Corporation and London Hydro. The project was one of six provincial clean energy projects unveiled recently by the Ontario Centres of Excellence.

Rajiv Varma of Western’s Electrical & Computer Engineering department says the project will dovetail nicely with the recent initiatives by the Ontario government.

“The government has instituted a standard offer program,” says Varma. “Solar power producers will get 42 cents per kilowatt which is seven times more than is paid for electricity.”

Varma says the provincial government also ensured that any company that wants to produce ten megawatts or over of solar power will be allowed to connect to the grid and have the 42 cents / kilowatt price guaranteed for 20 years.

“There is a rush from all of these solar producers to connect to the grid, about 1,200 to 1,300,” he says. “Last year the number of solar farm applications were half of the wind farm and now just in the last month solar has superseded wind applications.

Hydro One, which handles 95 per cent of the power distribution for the province has been connecting as many of these applications as possible mitigated by evaluating the impact of additions in terms of voltage levels, line losses, tranformer impact and such.

Varma says that this is where their new project comes in.

“Our power group and Waterloos group have been working with Hydro One in recent years to resolve the challenges in connecting wind farms,” he says. “We have all this experience and now the new challenge is to connect solar farms. The team has lots of experience in this.”

Varma says that having Hydro One as a project partner is a distinct positive for the long-term impact of solar power given that they handle 95 per cent of the province’s electricity and are working closely with project leaders to bring solar farms into the grid.

Key to the project Varma says is that Hydro One will integrate technology developed by the project into the grid as it is developed, a big difference he says from a typical pilot project scenario.

The project team consists of 16 members from both universities, ten coming from Western. Varma’s team includes five from Western’s Department of Electrical and Computer Engineering, two from the Boundary Layer Wind Tunnel and two from the Richard Ivey School of Business.

“It’s a terrific team,” says Varma. “The boundary layer people will the looking at the issue of wind and snow loading with regards to the farms and the Ivey people will help us with exploring land usage policies for installing renewable sources.”

Varma is Western’s project lead with M.M.A. Salama fulfilling the same role at the University of Waterloo.

The Western project team consists of T.S. Sidhu, A. Yazdani, J. Jiang, and G. Moschopoulos from the Electrical and Computer Engineering Department, Leo W.M. Lau from Surface Science Western, H. Hangan and J. Galsworthy from the Civil and Environmental Engineering Department & Boundary Layer Wind Tunnel and Guy Holburn and Tima Bansal from the Richard Ivey School of Business.

source: http://communications.uwo.ca/com/western_news/stories/$6_million_project_to_bring_solar_power_to_electrical_grid_20080214441427/

What is wind energy?

In reality, wind energy is a converted form of solar energy. The sun's radiation heats different parts of the earth at different rates-most notably during the day and night, but also when different surfaces (for example, water and land) absorb or reflect at different rates. This in turn causes portions of the atmosphere to warm differently. Hot air rises, reducing the atmospheric pressure at the earth's surface, and cooler air is drawn in to replace it. The result is wind.
Air has mass, and when it is in motion, it contains the energy of that motion("kinetic energy"). Some portion of that energy can converted into other forms mechanical force or electricity that we can use to perform work.

More reading: “Where Does Wind Energy Come From” and its subsections contain a very extensive description of the various geographical and geophysical factors that drive the circulation of the winds around our planet.


What is a wind turbine and how does it work?
A wind energy system transforms the kinetic energy of the wind into mechanical or electrical energy that can be harnessed for practical use. Mechanical energy is most commonly used for pumping water in rural or remote locations- the "farm windmill" still seen in many rural areas of the U.S. is a mechanical wind pumper - but it can also be used for many other purposes (grinding grain, sawing, pushing a sailboat, etc.). Wind electric turbines generate electricity for homes and businesses and for sale to utilities.
There are two basic designs of wind electric turbines: vertical-axis, or "egg-beater" style, and horizontal-axis (propeller-style) machines. Horizontal-axis wind turbines are most common today, constituting nearly all of the "utility-scale" (100 kilowatts, kW, capacity and larger) turbines in the global market.

Turbine subsystems include:

a rotor, or blades, which convert the wind's energy into rotational shaft energy;
a nacelle (enclosure) containing a drive train, usually including a gearbox* and a generator;
a tower, to support the rotor and drive train; and
electronic equipment such as controls, electrical cables, ground support equipment, and interconnection equipment.

*Some turbines do not require a gearbox
Wind turbines vary in size. This chart depicts a variety of historical turbine sizes and the amount of electricity they are each capable of generating (the turbine's capacity, or power rating).

The electricity generated by a utility-scale wind turbine is normally collected and fed into utility power lines, where it is mixed with electricity from other power plants and delivered to utility customers. Today (August 2005), turbines with capacities as large as 5,000 kW (5 MW) are being tested.

What are wind turbines made of?

The towers are mostly tubular and made of steel. The blades are made of fiberglass-reinforced polyester or wood-epoxy.

How big is a wind turbine?

Utility-scale wind turbines for land-based wind farms come in various sizes, with rotor diameters ranging from about 50 meters to about 90 meters, and with towers of roughly the same size. A 90-meter machine, definitely at the large end of the scale at this writing (2005), with a 90-meter tower would have a total height from the tower base to the tip of the rotor of approximately 135 meters (442 feet).
Offshore turbine designs now under development will have larger rotors—at the moment, the largest has a 110-meter rotor diameter—because it is easier to transport large rotor blades by ship than by land.
Small wind turbines intended for residential or small business use are much smaller. Most have rotor diameters of 8 meters or less and would be mounted on towers of 40 meters in height or less.

How much electricity can one wind turbine generate?

The ability to generate electricity is measured in watts. Watts are very small units, so the terms kilowatt (kW, 1,000 watts), megawatt (MW, 1 million watts), and gigawatt (pronounced "jig-a-watt," GW, 1 billion watts) are most commonly used to describe the capacity of generating units like wind turbines or other power plants.
Electricity production and consumption are most commonly measured in kilowatt-hours (kWh). A kilowatt-hour means one kilowatt (1,000 watts) of electricity produced or consumed for one hour. One 50-watt light bulb left on for 20 hours consumes one kilowatt-hour of electricity (50 watts x 20 hours = 1,000 watt-hours = 1 kilowatt-hour).
The output of a wind turbine depends on the turbine's size and the wind's speed through the rotor. Wind turbines being manufactured now have power ratings ranging from 250 watts to 5 megawatts (MW).

Example: A 10-kW wind turbine can generate about 10,000 kWh annually at a site with wind speeds averaging 12 miles per hour, or about enough to power a typical household. A 5-MW turbine can produce more than 15 million kWh in a year--enough to power more than 1, 400 households. The average U.S. household consumes about 10,000 kWh of electricity each year.
Example: A 250-kW turbine installed at the elementary school in Spirit Lake, Iowa, provides an average of 350,000 kWh of electricity per year, more than is necessary for the 53,000-square-foot school. Excess electricity fed into the local utility system earned the school $25,000 in its first five years of operation. The school uses electricity from the utility at times when the wind does not blow. This project has been so successful that the Spirit Lake school district has since installed a second turbine with a capacity of 750 kW. (For further information on this project, see at the Web site of the International Council for Local Environmental Initiatives.)

Wind speed is a crucial element in projecting turbine performance, and a site's wind speed is measured through wind resource assessment prior to a wind system's construction. Generally, an annual average wind speed greater than four meters per second (m/s) (9 mph) is required for small wind electric turbines (less wind is required for water-pumping operations). Utility-scale wind power plants require minimum average wind speeds of 6 m/s (13 mph).

The power available in the wind is proportional to the cube of its speed, which means that doubling the wind speed increases the available power by a factor of eight. Thus, a turbine operating at a site with an average wind speed of 12 mph could in theory generate about 33% more electricity than one at an 11-mph site, because the cube of 12 (1,768) is 33% larger than the cube of 11 (1,331). (In the real world, the turbine will not produce quite that much more electricity, but it will still generate much more than the 9% difference in wind speed.) The important thing to understand is that what seems like a small difference in wind speed can mean a large difference in available energy and in electricity produced, and therefore, a large difference in the cost of the electricity generated. Also, there is little energy to be harvested at very low wind speeds (6-mph winds contain less than one-eighth the energy of 12-mph winds).

How many turbines does it take to make one megawatt (MW)?

Most manufacturers of utility-scale turbines offer machines in the 700-kW to 2.5-MW range. Ten 700-kW units would make a 7-MW wind plant, while 10 2.5-MW machines would make a 25-MW facility. In the future, machines of larger size will be available, although they will probably be installed offshore, where larger transportation and construction equipment can be used. Units up to 5 MW in capacity are now under development.

How many homes can one megawatt of wind energy supply?

An average U.S. household uses about 10,655 kilowatt-hours (kWh) of electricity each year. One megawatt of wind energy can generate from 2.4 to more than 3 million kWh annually. Therefore, a megawatt of wind generates about as much electricity as 225 to 300 households use. It is important to note that since the wind does not blow all of the time, it cannot be the only power source for that many households without some form of storage system. The "number of homes served" is just a convenient way to translate a quantity of electricity into a familiar term that people can understand. (Typically, storage is not needed, because wind generators are only part of the power plants on a utility system, and other fuel sources are used when the wind is not blowing. According to the U.S. Department of Energy , "When wind is added to a utility system, no new backup is required to maintain system reliability." Wind Energy Myths, Wind Powering America Fact Sheet Series, http://www.nrel.gov/docs/fy05osti/37657.pdf .)

What is a wind power plant?

The most economical application of wind electric turbines is in groups of large machines (660 kW and up), called "wind power plants" or "wind farms." For example, a 107-MW wind farm near the community of Lake Benton, Minn., consists of turbines sited far apart on farmland along windy Buffalo Ridge. The wind farm generates electricity while agricultural use continues undisturbed.
Wind plants can range in size from a few megawatts to hundreds of megawatts in capacity. Wind power plants are "modular," which means they consist of small individual modules (the turbines) and can easily be made larger or smaller as needed. Turbines can be added as electricity demand grows. Today, a 50-MW wind farm can be completed in 18 months to two years. Most of that time is needed for measuring the wind and obtaining construction permits—the wind farm itself can be built in less than six months.

Source: http://www.awea.org/faq/wwt_basics.html

GIANT wind turbines may be coming to North Dorset.

GIANT wind turbines may be coming to North Dorset.
Parish planning chiefs will consider a proposal to build six turbines with blades 120 metres long near Gillingham.
The "wind park" is planned for the Silton district, and will require access roads and a sub-station.
The nearest dwelling would be just 500 metres from the turbines, with Gillingham town centre just over a mile away.
Ecotricity, the company behind the proposal, says the site at Silton was chosen after considering factors including wind speed and ease of connection to the national grid.
The aesthetic impact on the district has also been considered, says the company, which claims to have taken into account effects on the landscape, ecology, and culture of the district.
Noise from the giant blades, and the flicker of shadows, had been factored in to the proposal, the company adds.
The turbines could produce nearly 20 per cent of the suggested target for renewable electricity generation in Dorset by 2010.
Electricity for nearly 9,000 homes could be generated by the giant propellers, reducing North Dorset's carbon footprint by about 10,000 tonnes a year, according to Ecotricity.
Dorset environmentalist Angela Pooley said an environmental impact assessment would have to be made, but backed the use of wind farms in the county to produce renewable energy.
"We have to reduce our carbon footprint and that means looking at renewable sources of energy," said the Friends of the Earth co-ordinator.
But Bob Walter, the MP for North Dorset, opposed the turbines, saying they were unsightly, heavily subsidised and inefficient.
Gillingham Town Council's development control recommendations committee received a scoping report at their meeting on Monday.
Town councillors asked for a range of information prior to the planning application being submitted, ranging from reports on the access to the effect of bird migration.
Parish councils in Silton and Bourton have also been asked for their views.
source: http://www.thisisdorset.net/display.var.2038834.0.giant_wind_turbine_scheme_proposed.php

Destroying Native Ecosystems For Biofuel Crops Worsens Global Warming

Turning native ecosystems into "farms" for biofuel crops causes major carbon emissions that worsen the global warming that biofuels are meant to mitigate, according to a new study by the University of Minnesota and the Nature Conservancy.
The work will be published in Science later this month and was posted online Thursday, Feb. 7.
The carbon lost by converting rainforests, peatlands, savannas, or grasslands outweighs the carbon savings from biofuels. Such conversions for corn or sugarcane (ethanol), or palms or soybeans (biodiesel) release 17 to 420 times more carbon than the annual savings from replacing fossil fuels, the researchers said. The carbon, which is stored in the original plants and soil, is released as carbon dioxide, a process that may take decades. This "carbon debt" must be paid before the biofuels produced on the land can begin to lower greenhouse gas levels and ameliorate global warming.
The conversion of peatlands for palm oil plantations in Indonesia ran up the greatest carbon debt, one that would require 423 years to pay off. The next worst case was the production of soybeans in the Amazon, which would not "pay for itself" in renewable soy biodiesel for 319 years.
"We don't have proper incentives in place because landowners are rewarded for producing palm oil and other products but not rewarded for carbon management," said University of Minnesota Applied Economics professor Stephen Polasky, an author of the study. "This creates incentives for excessive land clearing and can result in large increases in carbon emissions.
"This research examines the conversion of land for biofuels and asks the question 'Is it worth it?," said lead author Joe Fargione, a scientist for The Nature Conservancy. "And surprisingly, the answer is no."
Fargione began the work as a University of Minnesota postdoctoral researcher with Polasky, Regents Professor of Ecology David Tilman; he completed it after joining the Nature Conservancy. They, along with university researchers Jason Hill and Peter Hawthorne, also contributed to the work.
"If you're trying to mitigate global warming, it simply does not make sense to convert land for biofuels production," said Fargione. "All the biofuels we use now cause habitat destruction, either directly or indirectly. Global agriculture is already producing food for six billion people. Producing food-based biofuel, too, will require that still more land be converted to agriculture."
These findings coincide with observations that increased demand for ethanol corn crops in the United States is likely contributing to conversion of the Brazilian Amazon and Cerrado (tropical savanna). American farmers traditionally rotated corn crops with soybeans, but now they are planting corn every year to meet the ethanol demand and Brazilian farmers are planting more of the world's soybeans. And they're deforesting the Amazon to do it.
The researchers also found significant carbon debt in the conversion of grasslands in the United States and rainforests in Indonesia.
Researchers did note that some biofuels do not contribute to global warming because they do not require the conversion of native habitat. These include waste from agriculture and forest lands and native grasses and woody biomass grown on marginal lands unsuitable for crop production. The researchers urge that all fuels be fully evaluated for their impacts on global warming, including impacts on habitat conversion.
"Biofuels made on perennial crops grown on degraded land that is no longer useful for growing food crops may actually help us fight global warming," said Hill. "One example is ethanol made from diverse mixtures of native prairie plants. Minnesota is well poised in this respect."
"Creating some sort of incentive for carbon sequestration, or penalty for carbon emissions, from land use is vital if we are serious about addressing this problem," Polasky said.
"We will need to implement many approaches simultaneously to solve climate change. There is no silver bullet, but there are many silver BBs," said Fargione. "Some biofuels may be one silver BB, but only if produced without requiring additional land to be converted from native habitats to agriculture."

The work was supported by the University of Minesota's Initiative for Renewable Energy and the Environment and the National Science Foundation.
Source: Patty Mattern University of Minnesota