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When the sun hits the earth and heats the air, it causes the air to rise, creating a vacuum below it. That vacuum pulls in cooler air creating wind. It is estimated that around 1% to 3% of the sun's energy entering the earth's atmosphere produces wind energy. Wind turbines are the most unused form of renewable energy found in high wind zone areas. According to the U.S. Department of Energy, there is enough harvestable wind to power the whole country. The world average wind speed is 3 m/s (10.8 km/h 6.75 mph). 18 to 20 mph winds flow through Rocky Mountain states. 12 to 18 mph breezes sweep across the Great Plains and upper Midwest states. Wind farms in 30 states currently provide less than 1% of the nation’s total electricity demand. The goal of the wind energy industry is to supply 100 gigawatts (10% of the projected national capacity) by 2020. 20percentwind.org wants 20% wind power by 2030. One study indicates that an entirely renewable energy supply based on 70% wind is attainable at today's power prices by linking wind farms with the electrical grid. Obviously, the other method of extracting the sun's energy is the use of solar cell panels or parabolic solar concentrators. Presently, solar cell power, costs several times more than wind energy to produce electricity.
A wind turbine is a machine that is used to convert kinetic energy from wind into mechanical energy. The wind turbine is called a windmill if the mechanical energy is used by machinery (pump, grinding stones, etc.). The wind turbine is called a wind generator, wind turbine, wind power unit (WPU), wind energy converter (WEC) or aerogenerator if the mechanical energy is converted into electricity. In the 10th century, vertical carousel-type windmills were used in Persia to grind corn and to raise water from streams for irrigation. The remains of foundations for vertical windmills / turbines have been found in France dating back to 1150. The first English post windmill was erected in 1137 A.D. by William Almoner of Leicester.
Presently, there are more Horizontal Axis Wind Turbines (HAWTs) producing electricity than vertical wind turbines. Helical Axis Wind Turbines produce electricity at around 35% efficiency. Most Vertical Axis Wind Turbines (VAWTs) produce electricity at around 25% efficiency, but they are cheaper to build and install, are smaller and produce less noise. The TSR (Tip Speed Ratio) is the ratio of the speed of the wind to the speed of the tips of the blades of a wind turbine. Lift-type wind turbines (HAWTs) have a maximum tip speed ratios of around 10, while drag-type wind turbines (VAWTs) have tip speed ratios of around 1.
A horizontal wind turbine usually has 3 or 4 aerodynamic blades which are shaped to catch the wind and rotate the blades on a horizontal axis. 5-blade wind turbines improve annual energy production in areas with average wind speeds of 11 MPH (5m/s). The blade rotation speed of a 5-blade turbine is 60% of the rotational speed of a 3-blade wind turbine. The slower blade rotational speed of a 5-blade wind turbine rwduces wind turbine noise. Compared to the annual energy output of a 3-blade wind turbine, there is an energy output increase of more than 60%. All horizontal wind turbines use some type of technology to help direct the blades into oncoming wind. Smaller horizontal wind turbines use a wind vane or vertical tail to turn the turbine's blades into the wind. Larger (commercial) horizontal wind turbines use sensitive wind and pressure sensors to communicate wind data to an onboard computer which continually turns the horizontal wind turbine's blades into the directional wind or to stop the blades from spinning in high speed winds. The horizontal wind turbine requires faster wind speeds to produce electricity. The vertical axis wind turbine (Savonious or helical) produces electricity with slower wind speeds and keep operating in high wind speeds.
Vertical axis wind turbines (VAWTs) have a vertical rotor drive shaft. A vertical axis wind turbine does not need to be pointed into the wind to work. This is advantageous when the wind direction comes in more than one direction or is turbulent. With a vertical axis wind turbine, the generator and gearbox are located at the base, where they are more accessible for maintenance. Drag type vertical axis wind turbines, such as the Savonius wind turbine and Giromill, operate at lower tip speed ratios than lift-based vertical axis wind turbines, such as Darrieus wind turbine ("Eggbeater" turbine) and Cycloturbine. Some vertical axis wind turbine designs produce pulsating torque. Later designs like Turby, Giromill, QuietRevolution and Aerotecture solved the torque problem by using the helical twist of the blades, similar to Gorlov's water turbines. The helical vertical axis wind turbine produces up to 50% more electricity annually, generates electricity in winds as low as 3 mph (1 m/s) and in wind speeds up to 130 mph+ (60 m/s). The helical vertical axis wind turbine withstands frost, ice, sand and humidity.
Vertical Axis Wind Turbines (VAWTs) are either lift or drag based designs. In the past, lift based designs have outputted more power and have been more efficient than drag based designs. The Finnish engineer S. J. Savonius invented the first Savonius vertical windmill in 1922. A Savonius wind turbine is a drag based turbine design (a/k/a anemometers & Flettner vent). A Savonius turbine's vanes can be made using scoops, buckets, paddles, sails, half drum sections, etc. Looking down on the rotor from above, a two scoop turbine would look like an “S” shape in cross section. The vertical S-shaped Savonius type rotor is the least efficient design. The barrel cut Savonius type rotor, where the 2 halves are offset (allowing air to pass through the middle), is slightly more efficient. The Savonius windmill rotates because air pressure is lower on one side and the cup side captures the wind. Most vertical Savonius type turbine designs produce pulsating torque. The spiral helix shaped Savonius type rotor catches omni-directional wind from all directions and angles, eliminates the pulsating torque and is more efficient at extracting kinetic wind power. The vertical Savonius type turbine is less efficient in turning wind power into energy than a Helical Axis Wind Turbine.
Terra-Aqua Moya has a few vertical axis turbines installed on a piece of private property, about one mile off of Route 25 on the Wyoming / Colorado border. Terra-Aqua Moya has a patented fixed blade shaped diffuser (similar to a series of Savonius blades) near the rotating vertical axis turbine blades. A trapezoid augmenter ramps the wind flow to the patented vertical blade shaped diffuser before it approaches the blades. Associated Press carried a story from the Jackson Hole Star-Tribune about a design breakthrough in vertical axis wind turbines announced by Terra-Aqua Moya of Cheyenne, Wyoming. Terra-Aqua Moya claims their patented design is 43% to 45% efficient. The Terra-Aqua Moya VAWT is close to the theoretical 59% maximum efficiency of horizontal axis wind turbines (HAWTs). Horizontal axis wind turbines are usually 25% to 40% efficient. The interaction between the vertical airfoils and curved vertical blades produces a low pressure area which accelerates wind flow through the turbine's blades. At a maximum height of 96 feet, the turbines can be placed in industrial areas where horizontal turbines are not allowed.
Many wind turbines have only a few moving parts (rotor, slip rings and yaw bearings). Conventional horizontal axis wind turbines (HAWTs) have three components: the rotor component / blades for converting wind energy to low speed rotational energy (20% of the wind turbine cost), the generator component / electrical generator, control electronics and gearbox for converting the low speed rotation to high speed rotation for generating electricity (34% of the wind turbine cost) and the structural support component / tower and rotor yaw mechanism (15% of the wind turbine cost) = 69% + transportation & installation. One of the main objectives of horizontal and vertical turbines manufacturers is to reduce these costs. Some of the horizontal axis wind turbine's transportation and installation costs exceed the cost of the turbine.
Wind speeds are slower closer to the ground. Wind speeds increase with height and accelerate as it rises over the eaves of a building. Air flow near the ground and other objects (buildings, trees, etc.) can create turbulent air flow, which can produce wind turbine vibration, noise and bearing wear. When a vertical axis wind turbine is mounted on a rooftop, the building redirects wind over the roof, increasing the wind speed entering the turbine. The energy that wind turbines generate is proportional to the cube of wind speed. A wind turbine in 20 mph of wind will generate 8x (eight times) as much energy as the same turbine in 10 mph of wind. In some wind shear locations, for every ten meters up, the wind speed can increase by 20% and the power output by 34%. Good locations for wind turbines are coastal areas with steady sea breezes, open flatlands such as the Great Plains, mesas, hilltops, ridgelines, etc. A turbine should be as high as possible and away from any obstructions. There is more wind the higher you get off the ground. Buildings, structures and trees play havoc with wind speed, direction and turbulence. A low-noise rooftop vertical axis wind turbine mounted at approximately 50% above the building height is located at the optimum height for maximum wind energy and minimum wind turbulence. A wind turbine spinning five feet above a rooftop will perform much better (2x better or more) if it’s 50 feet higher. Wind turbines with constant high wind speeds produce the best return on investment. The bottom of a horizontal turbine should be 3x above the nearest upwind barrier or 25 feet above any upwind obstacles within 300-500 feet.
The quantitative measurement of wind energy available at any location is called the Wind Power Density (WPD.) It is a calculation of the annual wind power available per square meter of swept area of a turbine and is tabulated for different heights above ground. Calculation of wind power density includes the effect of wind velocity and air density. In the United States, the calculations are created by the National Renewable Energy Lab and referred to as "NREL CLASS." The larger the WPD calculation, the higher it is rated by class. Classes range from Class 1 (200 watts/square meter or less at 50 meters altitude) to Class 7 (800 to 2000 watts/square meter). Commercial wind farms are usually located in Class 3 or higher areas.
A pole mounted wind turbine is a tall structure that requires a building permit. Zoning regulations often limit the height, placement, etc. of new building, so a conditional use permit or variance (project specific exception from existing zoning regulations) may be required. Applications for a variance should cite the specific rule and list the reasons why the wind turbine should be allowed. List all the other tall structures already accepted in your town (water towers, rooftop satellite dishes, cellular communications towers, etc.). Getting the required permits and approvals to install a wind turbine can be difficult when you elevate your turbine into the proper wind zones. There is a concern about the impact of turbines on birds and wildlife / noise and safety / visual appearance. You will probably have to submit a structural plan or the documentation from the turbine manufacturer or dealer to the county or city. Permitting requirements, procedures and fees vary. Fees for building permits, use permits, zoning permits and "plot plans" can range from hundreds to over a thousand dollars. There also may be other fees for public notification, hearings and environmental impact studies costing hundreds to several thousand dollars. Provide documentation or information that makes the fee unnecessary. If a fee seems inappropriate or excessive, you may be able to get it waived or reduced. Find out what you are being charged for.
The orientation and design of a building impacts the direction of airflow powering a roof mounted vertical axis wind turbine. Eaves and building contours increase turbulence and cause excessive and unbalanced loads on the turbine's blades which can lead to premature component failure. Turbulence may decrease the life of a turbine, but it can also increase energy output. Most residential and commercial roofs are not suited for large and heavy wind turbine installation because the roofs were not designed to carry the additional weight, dynamic loads and vibrations of the wind turbine.
At the 2009 American Wind Energy Association annual convention, Brad Cochran of CPP, presented a paper on "Optimizing the Placement of Building Integrated Wind Turbines." (HAWTs):
The average household uses 9,000 to 12,000 kWh of electricity a year. Small turbines used to power a single home or business may have a capacity of less than 100 kilowatts. A small turbine system can cost anywhere from $5,000 to $20,000+ installed. The energy produced by a wind turbine must be able to pay for itself in 10 years or less. Some large commercial sized turbines may have a capacity of 5 million watts (5 megawatts). The estimated price for large wind turbines is around $1,000 USD per 1 KW. Larger turbines are usually grouped together into wind farms to provide power to the electrical grid for powering a town or city. Turbines used in commercial wind farms, use three or four blades with tip speeds approaching 6 times the wind speed while producing high efficiency with a low torque ripple. The blades are pointed into the wind by computer controlled motors and the blades are usually colored light gray to blend in with the clouds. The blades range in length from 20 to 40 meters (65 to 130 ft) or more. The blades rotate at 10-22 revolutions per minute. A gear box is used to increase the speed of the generator. More energy can be produced by variable speed turbines using a solid state power converter to interface to the transmission system. Windterra’s VAWT inverter technology provides efficiencies at lower voltages (lower wind speeds) not found in the industry. All horizontal axis wind turbines are equipped with shut down features to avoid damage during high wind speeds. The tubular steel towers range from 200 to 300 feet (60 to 90 meters) tall.
Wind energy firms are developing efficient turbines that use multiple generators and strong, lightweight carbon-fiber or carbon-glass-hybrid rotor blades. Such upgrades will result in higher output wattage and lower production costs. The new efficient turbine's power output close to equals the natural gas–burning power plants. The 20 years of experience in designing and manufacturing Wind Turbines includes: Blade design (aerospace industry), Blade material (composite material, material sciences), Blade fabrication (composite material autoclave processing), Gearbox (precision machining, mechanical engineering), Synchronized generator (electrical engineering), Permanent magnet generator (electrical engineering), Inverter (power electronics, power distribution), High raised tower (steel production and fabrication), Blade and generator control (industrial control engineering) and Tower foundation excavation (geology, civil engineering).
On February 17, 2009, President Obama signed into law the American Recovery and Re-investment Act of 2009. The bill improved upon the 2008 tax credit by removing “cost caps”. Installed Wind Turbines qualify for a 30% federal tax credit and may be eligible for additional state and/or utility company tax credits. This allows consumers and small businesses to take a 30% tax credit off the installed cost of a wind turbine. Consumers and businesses also have the option of receiving the tax credit in the form of a cash grant. Federal regulations, the Public Utility Regulatory Policies Act of 1978 (PURPA), requires utilities to connect with and purchase power from all small wind energy systems (less than 80 MW). The wind turbine manufacturer or a consultant should be able to help arrange the required utility company approvals.
The cost of extending utility lines to a new home can cost as much as $20,000-30,000 per quarter mile. The Electric Power Research Institute suggests that in some areas of the United States, utilities would save money by removing the under-used electricity transmission lines, that are costly to maintain, and provide electricity with hybrid stand alone power generating and power storage systems. Other organizations: U.S. Department of Energy (DOE), U.S. Dept. of Energy Wind Powering America Program, Office of Energy Efficiency and Renewable Energy (EERE), Office of Electricity Delivery and Energy Reliability (OE), Power Marketing Administrations (PMAs), National Renewable Energy Laboratory (NREL), American Wind Energy Association (AWEA), Natural Resources Defense Council (NRDC) and National Wind Coordinating Collaborative (NWCC).
The Energy Revolutions Corporation teamed up with The New Hampshire Division of Parks & Recreation and a manufacturer representative for the installation of a 48″ 1,000 watt Greenpower Utility System (GUS™) vertical wind turbine on top of Mt. Washington. Mount Washington has the most severe wind and worst weather on the planet. Winds exceed hurricane force (75 mph) over one hundred days a year with an average wind velocity of 35 mph and an average temperature of 27.1 F (-2.7C). The highest wind velocity ever recorded on earth was 231 miles per hour on the summit of Mount Washington. The GUS™ vertical wind turbine was first installed on the roof of the Sherman Adams Summit Building in mid-December 2008. If a vertical wind turbine can survive a winter on top of Mount Washington, it will perform well in any other type of extreme condition anywhere in the world.
Metropolis Magazine's 2009 Next Generation contest challenged designers to "Fix Our Energy Addiction". The winning entry, called "Wind-it", was submitted by French designers Nicola Delon, Julien Choppin and Raphael Ménard. Ménard is the director of a 20 person conceptual and experimental research arm of a large French engineering firm (Iosis Group). The designers came up with the idea of inserting vertical wind turbines inside high voltage electrical transmission towers. The designers believe that if a third of France's electrical transmission towers had vertical turbines installed inside, they could crank out as much as two nuclear reactors (5% of the France's power needs). There are tens of millions of high voltage electrical transmission towers worldwide. The Helix Turbine System and Energy Production Means will allow this concept to come to life.
The present invention more than triples the efficiencies of all prior art vertical axis wind turbines and produces electricity in wind speeds as low as one mile per hour.
The present invention relates to multiple designs, arrangements and uses of omnidirection Savonius type turbines, omnidirection helix turbines and low pressure turbines for extracting and converting the kinetic energy from moving fluids (wind and water) into mechanical rotary energy for the preferred production of electricity.
There are many prior art disclosures and uses of omnidirection Savonius type turbines, omnidirection helix turbines and low pressure turbines to harness the kinetic energy from moving fluids, mostly the wind. Savonius’ first patent, US 1,697,574, was a vertical two bladed rotor designed to be powered by wind or flowing water. Since then, many attempts to use or modify the Savonius type turbine invention have been made. The most notable examples are found in US Patents 1,766,765, 4,293,274, 4,715,776, 4,784,568, 4,830,570, 4,838,757, 5,391,926, 5,494,407, 5,852,331, 6,283,711, 6,428,275, 6,465,899, 6,481,957, 6,538,340, 6,910,873, 7,132,760, 7,220,107, 7,241,105, 7,314,346, 7,329,965, 7,344,353, 7,362,004 and 7,371,135. There are other prior art references using the Savonius type turbine and helical turbine designs not mentioned or referenced. All of the Savonius type turbines and prior art turbines are connected to an axial drive shaft where the axial drive shaft end is attached to an alternator or some type of generator for harnessing the mechanical rotary energy from the spinning turbine and producing electricity.
It is an object of the present invention to provide multiple means of extracting the most kinetic energy from directional, omnidirectional and/or turbulent fluid movement using a multitude of modified preferably helix turbine designs and apparatuses to increase efficiencies. The more vanes the present invention’s turbine has, the more efficient it is at converting kinetic energy from directional, omnidirectional and/or turbulent fluid movement into mechanical rotary energy. A preferably cupped helix turbine vane has a greater ability to capture kinetic energy from directional, omnidirectional and/or turbulent fluid. These improvements allow the present invention to begin rotating and producing electricity in wind speeds slower than one mile per hour.
The present invention invention, more than triples the efficiency of all vertical prior art turbines.
A multitude of modifications and enhancements can be made to this helical turbine system invention and prior art turbines without departing from the spirit and scope of this invention as a whole.
These and other objects, features and advantages of the present invention will be better understood in connection with the following drawings and descriptions of the preferred embodiments.
For a better understanding of the invention as well as other objects, features and advantages thereof, reference is made to the following detailed description to be read in conjunction with the accompanying drawings, wherein:
FIG. 1A shows a cross sectional view, perpendicular to the axis, of a two-bladed helix turbine, where each blade is connected at the axis.
FIG. 1B shows an axial end perspective view of a of a two-bladed helix turbine, where each blade is connected at the axis.
FIG. 2A shows a cross sectional view, perpendicular to the axis, of a three-bladed helix turbine, where each blade is connected at the axis.
FIG. 2B shows an axial end perspective view of a of a three-bladed helix turbine, where each blade is connected at the axis.
FIG. 3A shows a cross sectional view, perpendicular to the axis, of a four-bladed helix turbine, where each blade is connected at the axis.
FIG. 3B shows an axial end perspective view of a of a four-bladed helix turbine, where each blade is connected at the axis.
FIG. 4A shows a cross sectional view, perpendicular to the axis, of a six-bladed helix turbine, where each blade is connected at the axis.
FIG. 4B shows an axial end perspective view of a of a six-bladed helix turbine, where each blade is connected at the axis.
These and other features of the present invention will be more fully understood by referencing the drawings.
While the present invention disclosed has been described with reference to the preferred embodiments thereof, a latitude of modification, change, relocation of elements, repositioning of elements and substitution is intended in the foregoing disclosure, and in some instances, some features of the invention will be employed without a corresponding use of the inventions other features. Accordingly, it will be appreciated by those having an ordinary skill in the art that various modifications can be made to the system of the invention and it is appropriate that the description and appended claims are construed broadly and in a manner consistent with the spirit and scope of the invention herein, without departing from the spirit and scope of the invention as a whole.