In terms of physics, energy is an indirectly pragmatic quantity that comes in many types such as potential energy, radiant energy, solar energy, kinetic energy and wind energy. In simple words, it is a crucial element required for performing mechanical task. Mainly energy comes from two sources such as renewable or non renewable. Renewable sources are those which can be renewed again and again such as sunlight, rain, waves, tides, wind and geothermal heat. On the other hand, non renewable sources are those which cannot be used again such as fossil fuels, coal, petroleum and natural gas.
Wind is a renewable source of energy. The force produced by wind is termed as wind energy. Wind energy is used for producing electricity with the help of turbines. Turbines for Wind Power converts kinetic energy into mechanical energy with the help of wind forces. Wind power refers to the process of converting one form of energy into other. The device which is used for the process of wind power is known as wind power plant or wind turbine. The mechanical energy produced from wind turbine is used for many purposes such:
Wind power is consistently pure and completely renewable. It does not emit any harmful radiations, therefore it is clean process. It keeps the environment pollution free and healthy. Wind turbine consists of mainly two axis such as horizontal and vertical. Horizontal axis of wind turbines is equipped with electrical generator, blades and rotor shaft. Wind sensors are also there in large turbines. Turbine blades are specially designed for pushing purposes. Turbine blades are located at a significant distance in front of the tower and are twisted towards the wind forces. The blades are positioned in such a way that support is being provided to the tower. These turbines are used for commercial production of electric power in wind farms. These turbines are highly reliable and durable. They offer speed up to over 320 km/h (200 mph) and are highly efficient. Turbines are also accompanied with gear box, which is specifically used for speeding up the generators.
Also, there is a vertical axis twisted turbine. The vertical axis is mainly equipped with rotor shaft running perpendicularly. Gear box is placed at the bottom of the turbine. Following are the types of vertical axis of wind turbines such as:
Darrieus Wind Turbines: these are specially designed to create cyclic strain on the tower. This type is highly economical. It contains three turbine blades in it. The structure is placed on bottom up type.
Aerodynamic turbine: it is made up of airfoil and specifically designed for capturing kinetic energy. It provides an artificial current to the center. It has many advantages over large turbines. It may work in creeks, oceans, rivers and many more.
Also, there are many other types of vertical axis such as Giromill, Savonius Wind Turbine mills and many more.
Wind generators are an effective source of renewable power in many areas across the world. To make sure a small wind system is right for you, there are things to consider:
- You have at least 4.5 m/s (10 MPH ) average wind speed. Best results at 12 MPH (5.4 m/s) or more.
- Your property is unobstructed from tall buildings and trees. Ideally, you should have 0.5 acres or more
- The local zoning allows a structure that is at least 12.8 m (42 feet) tall
- Your local utility has an existing interconnection agreement
Once you have determined you have the right conditions for a wind power system, you will need to consider the best place on your property. Proper siting is critical to the performance and longevity of your investment. It can make the difference between years of trouble free operation or continuous frustration.
This guide is a precursor to investing in a small residential scale wind power generator. Whether your reason for investing is because of your concern for the environment, helping reduce foreign fuel imports or pure economics, we at Energy Matters want to make sure you get the most from your wind generator. Before making any investment in small wind, be sure to review this guide carefully, ask lots of questions and once you feel confident, call Energy Matters!
Determining your wind resource
“Do I have enough wind?” is often the first and most asked question. Generally, if you feel like you have a very windy site, you most likely have a good place for a wind power system. It is always a good idea to do your homework just to make sure. Wind resources can vary from placed to place. There are several places you can go to assist you.
The Bureau of Meteorology has recorded a series wind data for much of Australia that will give you a good idea what your wind resource is at your location.
Please note that winds decrease the closer they are to the ground.
You may also obtain wind data from your local weather station, university or even television station. Airport data is not recommended. Airports are generally located in lower wind areas (valleys) and their measurement techniques do not produce good data.
Griggs-Putnam Index. *Probable mean annual windspeed.
Data prepared by E.W. Hewson, J.E. Wade, and R.W. Baker of Oregon State University
If wind maps or local data doesn’t work, another method is looking around and observing of the deformation of vegetation and trees on and around your property. The Griggs-Puttnam Index was a scientific study that looked at how wind deformed vegetation to determine the wind resource at a particular site. Compare the drawing above with your own property to determine your wind resource.
Another strategy is conducting an actual wind resource assessment. This is by far the most accurate way of doing a site assessment but it is also the most expensive and time consuming if you hire someone else to perform the work. A more economical solution are one of the tools that measures solar and wind energy at your site that you can install yourself.
Should I meter my site?
Up until recently, the answer would have been no as the cost of an accurate data logging system was almost as much as a small wind power system. However, newer tools are a very economical solution for gaining an accurate measurement over a period of time.
Avoid hand-held anemometers as they only measure the reading at arm’s length and certain times of the day. The do not give an accurate overall wind speed for your site at the height that you would install.
Once you have determined you have a good wind resource, you will want to site your wind generator in the most optimum place.
The ideal position for a wind power generator is a flat open space with good wind from at least one direction (known as the prevailing wind direction), a coastline, or a smooth hill top with an open area in the prevailing wind. The wind speeds up significantly near the top of the hill and the air flow should be reasonably smooth and free from excessive turbulence.
Excessive turbulence or “bad wind” causes fatigue damage and shortens a generator’s working life. When siting, keep away from local obstructions such as large trees and houses, or use a taller tower to ensure that the generator is well above the obstructions. Wind speed also increases with height so it is best to have the generator as high as your zoning laws and investment payback will allow. It is recommended to site you generator at least 6 m (20 feet) above any surrounding obstacles such as trees or buildings in a 76 m (250 foot) radius (see general siting image above).
What is the “best” site?
Wind resource is not the only consideration when siting. Components such as taller towers and running large amounts of wire more than 152 m (500 feet) from your site can add significant costs to your wind system. You will need to balance power achieved in the best wind site over the cost of installation to determine the best overall placement of your system.
3 typical siting Considerations
Coastal or Lakeside
Very strong prevailing winds typically blow from the ocean. If this is the case, it is very important to install your wind generator as close to the coastline as possible. Trees and taller structures can be down-wind from the wind generator.
Wind compresses as it blows over the top of a hill, increasing the wind speed. With proper placement, you may be able to use a shorter tower. We never recommend anything shorter than 10 m (33 feet). It is important to follow the general rule; that is the tower must be at least 6 m (20 feet) above any surrounding object.
Winds may be very turbulent running off a cliff causing wind shears. It is important to site the generator far enough from the cliff to avoid turbulent wind.
Because wind speeds increase with height, a residential wind generator is mounted on a tower. The tower also raises the generator above the air turbulence that can exist close to the ground because of obstructions such as hills, buildings, and trees.
Your wind resource will be cleaner and stronger the higher you go. The taller your tower, the better your power output. However, taller towers will increase the cost your installation and may not be allowed in some areas. While you should install your system in the tallest tower allowed, it is best to evaluate your overall energy and cost payback before investing in taller towers (see diagram at right, top).
Types of Towers
The two most common types of towers are guyed and monopole. Both are available in various designs. Some can be tilted-down for easy access while others require a crane for installation and service (see diagram below).
Guyed towers are less expensive than monopole towers. However, because the guy radius must be one-half to three-quarters of the tower height, guyed towers require enough space to accommodate them.
Monopole towers are more expensive but they offer the consumer an easy way to perform maintenance. Monopole towers can be lowered to the ground during hazardous weather such as hurricanes (see diagram on next page). Aluminium towers are prone to cracking and should be avoided.
Installation or Mounting
A general rule of thumb is to install a small wind power generator on a tower with the bottom of the rotor blades at least 6 m (20 feet) above any obstacle that is within 76 m (250 feet) of the tower, 7.6 m (25 feet) to the hub.
Can I mount this on my roof?
Mounting small wind generators over 500 watts on rooftops is not recommended. Larger residential home wind generators vibrate and transmit noise to the structure on which they are mounted. This vibration can lead to noise and structural problems with the building. Mounting on the rooftop can also expose the generator to excessive turbulence that shortens its life.
- Determine if you have enough wind for a wind generator and the best resource on your site.
- Try to have clear, smooth access to the prevailing wind, e.g. over open water or smooth ground. If possible site the generator on a smooth hill.
- Mount the generator on as high a tower as possible and well clear of obstructions, but do not go to extremes. Easy access will be required for erection and foundations for the tower may be needed depending on the size and tower type. Remember, higher towers will add cost to the system that may not be countered by the energy output achieved. It is also important to ensure that the wind generator can be easily lowered for inspection and maintenance.
- Consult your local council as to whether you need planning permission. You should try to minimize the environmental impact of the generator, and it will be helpful to inform your neighbors of your plans at early stage.
- If planning an interconnected system, consult with your utility to obtain an interconnection agreement.
Microsoft has inked two agreements for wind power in the USA, which combined represent 237 megawatts of capacity.
Microsoft contracted with Allianz Risk Transfer (ART) to purchase the certificates accompanying the new 178-megawatt Bloom Wind project in Kansas, using a new structure that the company states has the potential to bring clean energy projects online at a more rapid clip.
The second agreement involves the purchase 59 megawatts of renewable energy certificates from the Happy Jack and Silver Sage wind projects, which are situated next to Microsoft’s Cheyenne, Wyoming, datacenter. The arrangement will cover all the electricity use of the datacenter.
Announced early this week, the new additions to Microsoft’s renewable energy stable bring the company’s total investment in wind energy projects in the U.S. to more than 500 megawatts.
“Microsoft is committed to building a responsible cloud, and these agreements represent progress toward our goal of improving the energy mix at our datacenters,” said Brad Smith, Microsoft’s president and chief legal officer. “Our commitment extends beyond greening our own operations because these projects help create a greener, more reliable grid in the communities in which we operate.”
The projects join the 175-megawatt Pilot Hill wind farm in Illinois and 110-megawatt Keechi wind projectin Texas.
In May this year, Microsoft committed to increasing the amount of directly-sourced solar, wind and hydropower used in its datacentres to 50 percent by 2018 and has set an additional goal of 60 percent early in the next decade.
In May, while the company was already sourcing 100 percent of the electricity used by its datacentres from renewables, only approximately 44 percent of that power was sourced from wind, solar and hydropower.
Microsoft is a heavy-hitter in the U.S. Environment Protection Agency’s (EPA’s) Green Power Partnership and has been carbon-neutral since June 2012.
According to the Partnership’s recently updated Top 100, Microsoft’s annual green power consumption was 2,699,210,000 kWh. It ranks no.2 on the list, behind Intel Corporation. Microsoft was Partner of the Year in 2012, 2013 and 2015.
The software and cloud services giant says it has been 100 percent powered by renewable energy since 2014.