Wind Power
US wind speed averages
Wind power. The phrase ‘wind power’ can be explained as the process by which wind energy is harnessed. The kinetic energy from light air, fresh breezes to near gales has been captured for thousands of years by seafarers to windsurfers, kite fliers to hang gliders, farmers to millers & now power generation companies to the homeowner.
Wind power exists by virtue of many natural forces & phenomena. Wind circulates around the globe continuously as a result of solar radiation heating the earth’s terrain & atmosphere in varying amounts dependent on factors like geology, climate, latitude, topography, altitude & seasons. We’ve all seen broadcasts of the weather on the news depicting isobars on a map of your state or country which represent areas of equal barometric pressure. When they’re closer together, winds are stronger – as in a low pressure cell associated with colder weather, storms & in the extreme, hurricanes or cyclones depending where you live. Widely spaced isobars represent relatively calm conditions but by no means accurate for any given location. Formerly measured in millibars, most countries now quantify isobars in hectopascals.
Differences in atmospheric pressure also drive wind movements & advection facilitates the conveyance of warm & cold air as well as humidity. Cool, dense, heavier air will gravitate towards pockets where lighter warm air is displaced. The many different layers of the atmosphere affect the intensity of wind power which can be experienced on a macro level e.g. trade winds, jet streams, easterlies & westerlies or influenced on a micro or local level e.g. water bodies, areas of dense or no vegetation, mountain ranges, built up areas, cliff tops & valleys to name a few.
Is capturing wind energy cost effective? Wind power is virtually a zero cost resource that is still largely untapped. Studies have shown that wind energy has the potential to provide more than enough electrical power to meet the needs of every household or business on earth alone. Our reliance on coal & nuclear power could be done away with completely purely by concentrating our efforts to capture wind power. Can the average householder make a difference by collecting their own green energy? Yes you can. There now lies a wealth of knowledge in book stores, libraries & on the internet about how we all can make a difference to your own situation on a micro level but if a lot of people get on board the results can be seen on a macro level.
What do I mean by this? Modern technology has provided us with the know-how to ‘green’ our homes more efficiently than ever before. Home solar power technology has gone ahead in leaps & bounds & is gaining popularity with governments who are willing to subsidize the installation costs of homemade green energy. Harnessing wind power is gaining momentum as a more cost effective way to power one’s home given the elevated costs involved with professionally installed solar powered systems. In fact, the larger & higher your wind power system is, the cheaper it becomes to produce electricity. Conversely, the larger the solar power array is, the cost per produced kW/h is increased due to the initial layout cost.
What type of wind powered system is right for my area? There are many different systems out in the market to capture wind power & these can be assembled by the home handy-person from kits, erected professionally or build your own from scratch. There is quite a range of wind power turbine designs with loop-wing turbines, vertical axis turbines & savonius turbines. Multiple blade (e.g. windmill) turbines & propellar blade turbines are the most common for small & large scale residential wind powered electricity generation & are by far the most cost effective designs. Obviously producing electricity is reliant on the consistency of breeze in your locality & if it’s not quite up to scratch then combining your wind powered system with a solar powered system could be an option. These hybrid systems are very complimentary – during the short day periods in winter a solar powered system’s ability is reduced but wind speed averages are greater. But during the long day periods in summer wind speed averages are decreasing but solar insolation is at its most beneficial to produce power for your home. There are other aspects involved. How much do you want to spend on a system? Do you want to minimize your electric bill or would you like to make your electricity meter spin backwards? Can I reduce my household consumption enough to really enjoy the benefits from a wind powered system? Is the average wind speed high enough where I live? Can I erect a system if I live in a built up area? If so, are there local/county regulations to take into account like height restrictions, noise levels, potential bird strikes, the effect on the street-scape etc?
How can I find out about the amount of wind energy in my area? An excellent resource for wind maps for US residents is the Dept. of Energy’s website – Wind Powering America. You can use this data to determine the viability of a wind powered system for your home & what type or size you may require. Bear in mind that the data is compiled at a height of 80m (263 ft) & average wind speeds will be at a reduced amount at levels that you would locate your residential wind powered system. The higher the better as wind power density increases with altitude. An obstacle free path for your wind power is critical when placing your turbine of choice. In terms of a wind resource assessment, there are 7 different classes of wind speeds ranging from one – 0 to 4.4 m/s (9.8 mph) thru seven – 9.4 m/s (21 mph) at 10m (33 ft). The density at 50m (164 ft) is double that at 10m but the density at class 7 is 10 times greater than at class 1.
By using this data, we can assess what type of turbine is needed relative to the amount of wind energy you’d like to collect & the amount of potential wind power present where you live. For optimum results, we’d like these to match. For example, if you live in a class 3 area, the minimum wind speed is an average of 5.6 m/s (12.5 mph) at 10m. This is probably the bare minimum for the majority of systems out on the market today. Multi blade turbines have a low start up speed so they can operate effectively in a broader range of wind speeds. There are multi blade systems that can produce power at class 1 wind speeds of 1 m/s all the way thru to 18 m/s before it will shut itself down. In class 4 wind speeds (6 m/s or 13 mph), typically it will produce 230 kw/h of power per month. Let’s say you’ve reduced your household consumption to 20 kw/h per day, this represents a 38% reduction in your power bill. Pretty good savings. For another example, a propeller blade system with a rated output of 1kw at class 4 wind speeds can produce around 220 kw/h of power per month. Its start up speed is 3.5 m/s so these wind powered systems are best suited to areas of higher average wind speed. These 2 turbines cost around the same.
What does a wind powered system consist of? This is entirely dependent on the type of system you desire & your goals with respect to harnessing wind power. If you plan to or actually live in a remote area is it even possible for the utility company to construct powerline infrastructure to your locality? This could be a major headache if it’s even at all possible not to mention the obscene cost you’d have to bear as well as potential easement issues. Solution? An off-grid system includes your choice of wind turbine & tower assembly. The tower may consist of a rigid mast or better yet a post with 4 guy cables increasing its stability significantly. The latter is also cheaper. Your turbine will be wired to a regulator or control box which will direct your wind power to a bank of batteries to store the collected energy. From there your wind power is fed to an inverter to convert the DC power into usable AC power for your home.
Other options are on-grid or grid tie-in systems which have similar components but are directly connected to the electricity grid via a special on-grid inverter & a power metering device that doesn’t require a battery bank as backup. Another type utilizes batteries & is connected to your home as well as the grid. This system will give you an uninterrupted supply of power whereas if you employ the direct on-grid system, you’re at the mercy of the power supplier & any brownouts or blackouts.
The deep cycle batteries that are employed consist of 3 main types – AGM (absorbed glass mat), gel cell & flooded lead acid (FLA). The gel cell & AGM are valve-regulated lead-acid (VRLA) batteries & don’t require any maintenance with the gel cells being the most expensive. The FLA batteries are the cheapest of the 3 but must be stored upright in a ventilated space & require maintenance. There are many factors involved in calculating the optimum number & size of batteries including your average power consumption, the number of days that you’d solely use battery power i.e. calm days, the maximum amount of battery discharge & temperature variations during the year.
Producing your own wind power can have many other benefits besides lowering your electricity bill. Several states have property tax incentives, sales tax incentives, state rebate programs, feed in tariffs, state loan programs & personal tax credits to name a few.
Below is a list of renewable energy incentives for each state & the District of Columbia. Click on your individual state to find out more. Information courtesy of the Database of State Incentives for Renewables & Efficiency website.
Alabama Alaska Arizona Arkansas
Colorado California Connecticut Delaware
Florida Georgia Hawaii Idaho
Illinois Indiana Iowa Kansas
Kentucky Louisiana Maine Maryland
Massachusetts Michigan Minnesota Mississippi
Missouri Montana Nebraska Nevada
New Hampshire New Jersey New Mexico New York
North Carolina North Dakota Ohio Oklahoma
Oregon Pennsylvania Rhode Island South Carolina
South Dakota Tennessee Texas Utah
Vermont Virginia Washington West Virginia
Wisconsin Wyoming District of Columbia
It is well worth the time researching ways & means of minimizing the cost of setting up & producing wind power. If we all did a little bit to ease the burden on our electricity infrastructure, imagine the benefits to the air we breathe, the price we pay & the smaller our carbon footprint on our beautiful mother earth.
Wind power exists by virtue of many natural forces & phenomena. Wind circulates around the globe continuously as a result of solar radiation heating the earth’s terrain & atmosphere in varying amounts dependent on factors like geology, climate, latitude, topography, altitude & seasons. We’ve all seen broadcasts of the weather on the news depicting isobars on a map of your state or country which represent areas of equal barometric pressure. When they’re closer together, winds are stronger – as in a low pressure cell associated with colder weather, storms & in the extreme, hurricanes or cyclones depending where you live. Widely spaced isobars represent relatively calm conditions but by no means accurate for any given location. Formerly measured in millibars, most countries now quantify isobars in hectopascals.
Differences in atmospheric pressure also drive wind movements & advection facilitates the conveyance of warm & cold air as well as humidity. Cool, dense, heavier air will gravitate towards pockets where lighter warm air is displaced. The many different layers of the atmosphere affect the intensity of wind power which can be experienced on a macro level e.g. trade winds, jet streams, easterlies & westerlies or influenced on a micro or local level e.g. water bodies, areas of dense or no vegetation, mountain ranges, built up areas, cliff tops & valleys to name a few.
Is capturing wind energy cost effective? Wind power is virtually a zero cost resource that is still largely untapped. Studies have shown that wind energy has the potential to provide more than enough electrical power to meet the needs of every household or business on earth alone. Our reliance on coal & nuclear power could be done away with completely purely by concentrating our efforts to capture wind power. Can the average householder make a difference by collecting their own green energy? Yes you can. There now lies a wealth of knowledge in book stores, libraries & on the internet about how we all can make a difference to your own situation on a micro level but if a lot of people get on board the results can be seen on a macro level.
What do I mean by this? Modern technology has provided us with the know-how to ‘green’ our homes more efficiently than ever before. Home solar power technology has gone ahead in leaps & bounds & is gaining popularity with governments who are willing to subsidize the installation costs of homemade green energy. Harnessing wind power is gaining momentum as a more cost effective way to power one’s home given the elevated costs involved with professionally installed solar powered systems. In fact, the larger & higher your wind power system is, the cheaper it becomes to produce electricity. Conversely, the larger the solar power array is, the cost per produced kW/h is increased due to the initial layout cost.
What type of wind powered system is right for my area? There are many different systems out in the market to capture wind power & these can be assembled by the home handy-person from kits, erected professionally or build your own from scratch. There is quite a range of wind power turbine designs with loop-wing turbines, vertical axis turbines & savonius turbines. Multiple blade (e.g. windmill) turbines & propellar blade turbines are the most common for small & large scale residential wind powered electricity generation & are by far the most cost effective designs. Obviously producing electricity is reliant on the consistency of breeze in your locality & if it’s not quite up to scratch then combining your wind powered system with a solar powered system could be an option. These hybrid systems are very complimentary – during the short day periods in winter a solar powered system’s ability is reduced but wind speed averages are greater. But during the long day periods in summer wind speed averages are decreasing but solar insolation is at its most beneficial to produce power for your home. There are other aspects involved. How much do you want to spend on a system? Do you want to minimize your electric bill or would you like to make your electricity meter spin backwards? Can I reduce my household consumption enough to really enjoy the benefits from a wind powered system? Is the average wind speed high enough where I live? Can I erect a system if I live in a built up area? If so, are there local/county regulations to take into account like height restrictions, noise levels, potential bird strikes, the effect on the street-scape etc?
How can I find out about the amount of wind energy in my area? An excellent resource for wind maps for US residents is the Dept. of Energy’s website – Wind Powering America. You can use this data to determine the viability of a wind powered system for your home & what type or size you may require. Bear in mind that the data is compiled at a height of 80m (263 ft) & average wind speeds will be at a reduced amount at levels that you would locate your residential wind powered system. The higher the better as wind power density increases with altitude. An obstacle free path for your wind power is critical when placing your turbine of choice. In terms of a wind resource assessment, there are 7 different classes of wind speeds ranging from one – 0 to 4.4 m/s (9.8 mph) thru seven – 9.4 m/s (21 mph) at 10m (33 ft). The density at 50m (164 ft) is double that at 10m but the density at class 7 is 10 times greater than at class 1.
By using this data, we can assess what type of turbine is needed relative to the amount of wind energy you’d like to collect & the amount of potential wind power present where you live. For optimum results, we’d like these to match. For example, if you live in a class 3 area, the minimum wind speed is an average of 5.6 m/s (12.5 mph) at 10m. This is probably the bare minimum for the majority of systems out on the market today. Multi blade turbines have a low start up speed so they can operate effectively in a broader range of wind speeds. There are multi blade systems that can produce power at class 1 wind speeds of 1 m/s all the way thru to 18 m/s before it will shut itself down. In class 4 wind speeds (6 m/s or 13 mph), typically it will produce 230 kw/h of power per month. Let’s say you’ve reduced your household consumption to 20 kw/h per day, this represents a 38% reduction in your power bill. Pretty good savings. For another example, a propeller blade system with a rated output of 1kw at class 4 wind speeds can produce around 220 kw/h of power per month. Its start up speed is 3.5 m/s so these wind powered systems are best suited to areas of higher average wind speed. These 2 turbines cost around the same.
What does a wind powered system consist of? This is entirely dependent on the type of system you desire & your goals with respect to harnessing wind power. If you plan to or actually live in a remote area is it even possible for the utility company to construct powerline infrastructure to your locality? This could be a major headache if it’s even at all possible not to mention the obscene cost you’d have to bear as well as potential easement issues. Solution? An off-grid system includes your choice of wind turbine & tower assembly. The tower may consist of a rigid mast or better yet a post with 4 guy cables increasing its stability significantly. The latter is also cheaper. Your turbine will be wired to a regulator or control box which will direct your wind power to a bank of batteries to store the collected energy. From there your wind power is fed to an inverter to convert the DC power into usable AC power for your home.
Other options are on-grid or grid tie-in systems which have similar components but are directly connected to the electricity grid via a special on-grid inverter & a power metering device that doesn’t require a battery bank as backup. Another type utilizes batteries & is connected to your home as well as the grid. This system will give you an uninterrupted supply of power whereas if you employ the direct on-grid system, you’re at the mercy of the power supplier & any brownouts or blackouts.
The deep cycle batteries that are employed consist of 3 main types – AGM (absorbed glass mat), gel cell & flooded lead acid (FLA). The gel cell & AGM are valve-regulated lead-acid (VRLA) batteries & don’t require any maintenance with the gel cells being the most expensive. The FLA batteries are the cheapest of the 3 but must be stored upright in a ventilated space & require maintenance. There are many factors involved in calculating the optimum number & size of batteries including your average power consumption, the number of days that you’d solely use battery power i.e. calm days, the maximum amount of battery discharge & temperature variations during the year.
Producing your own wind power can have many other benefits besides lowering your electricity bill. Several states have property tax incentives, sales tax incentives, state rebate programs, feed in tariffs, state loan programs & personal tax credits to name a few.
Below is a list of renewable energy incentives for each state & the District of Columbia. Click on your individual state to find out more. Information courtesy of the Database of State Incentives for Renewables & Efficiency website.
Alabama Alaska Arizona Arkansas
Colorado California Connecticut Delaware
Florida Georgia Hawaii Idaho
Illinois Indiana Iowa Kansas
Kentucky Louisiana Maine Maryland
Massachusetts Michigan Minnesota Mississippi
Missouri Montana Nebraska Nevada
New Hampshire New Jersey New Mexico New York
North Carolina North Dakota Ohio Oklahoma
Oregon Pennsylvania Rhode Island South Carolina
South Dakota Tennessee Texas Utah
Vermont Virginia Washington West Virginia
Wisconsin Wyoming District of Columbia
It is well worth the time researching ways & means of minimizing the cost of setting up & producing wind power. If we all did a little bit to ease the burden on our electricity infrastructure, imagine the benefits to the air we breathe, the price we pay & the smaller our carbon footprint on our beautiful mother earth.
