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
Thursday, February 14, 2008
How To: Build Your Own 1000 Watt Wind Turbine
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.
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 .)
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.
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
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