Wind Energy : Wind Energy Slide 2: History - Meet the Ancestors 1000BC Nile Delta
First windmills Slide 3: Meet the Ancestors 500BC Persia
Pumping water Slide 4: Meet the Ancestors Crete
Pumping water and grinding 1000AD Slide 5: Meet the Ancestors 1800’s US
Pumping water Slide 6: Meet the Ancestors Jack & Jill in Sussex First UK windmill in Weedly, Yorkshire in 1185 1821 Slide 7: Meet the Ancestors 1941 US
1st grid connection Slide 8: Meet the Ancestors 1982 UK
First composite blades Slide 9: Meet the Ancestors Global
Vestas employs 1000 in UK 2008 Slide 12: As early as 1390, the Dutch set out to refine the tower mill design, which had appeared somewhat earlier along the Mediterranean Sea (Figure 3, above left). The Dutch essentially affixed the standard post mill to the top of a multi-story tower, with separate floors devoted to grinding grain, removing chaff, storing grain, and (on the bottom) living quarters for the wind smith and his family.
Both the post mill and the later tower mill design had to be oriented into the wind manually, by pushing a large lever at the back of the mill. Optimizing windmill energy and power output and protecting the mill from damage by furling the rotor sails during storms were among the wind smith's primary jobs. Slide 16: Between 1850 and 1970, over six million mostly small (1 horsepower or less) mechanical output wind machines were installed in the U.S. alone. The primary use was water-pumping and the main applications were stock watering and farm home water needs. Very large windmills, with rotors up to 18 meters in diameter, were used to pump water for the steam railroad trains that provided the primary source of commercial transportation in areas where there were no navigable rivers.
In the late 19th century, the successful "American" multi-blade windmill design was used in the first large windmill to generate electricity. The most obvious influence on 20th century wind power was the increasing use of electricity. But this started with a look to the past. : First Use of Wind for "Large- Scale" Generation of Electricity
The first use of a large windmill to generate electricity was a system built in Cleveland, Ohio, in 1888 by Charles F. Brush. The Brush machine (shown at right) was a postmill with a multiple-bladed "picket-fence" rotor 17 meters in diameter, featuring a large tail hinged to turn the rotor out of the wind. It was the first windmill to incorporate a step-up gearbox (with a ratio of 50:1) in order to turn a direct current generator at its required operational speed (in this case, 500 RPM.) Figure 6. The Brush postmill in Cleveland, Ohio, 1888. The first use of a large windmill to generate electricity. Note the man mowing the lawn at lower right. The most obvious influence on 20th century wind power was the increasing use of electricity. But this started with a look to the past. Slide 18: Despite its relative success in operating for 20 years, the Brush windmill demonstrated the limitations of the low-speed, high-solidity rotor for electricity production applications. The 12 kilowatts produced by its 17-meter rotor pales beside the 70-100 kilowatts produced by a comparably-sized, modern, lift-type rotor.
In 1891, the Dane Poul La Cour developed the first electrical output wind machine to incorporate the aerodynamic design principles (low-solidity, four-bladed rotors incorporating primitive airfoil shapes) used in the best European tower mills. The higher speed of the La Cour rotor made these mills quite practical for electricity generation.
By the close of World War I, the use of 25 kilowatt electrical output machines had spread throughout Denmark, but cheaper and larger fossil-fuel steam plants soon put the operators of these mills out of business. Slide 19: Small System Pioneers
The first small electrical-output wind turbines simply used modified propellers to drive direct current generators. By the mid-1920's, 1 to 3-kilowatt wind generators developed by companies like Parris-Dunn and Jacobs Wind-electric found widespread use in the rural areas of the midwestern Great Plains. (A 3-kilowatt Jacobs unit is shown at right, being adjusted by a cigarette-puffing M.L. Jacobs at Rocky Flats, Colorado in 1977.)
These systems were installed at first to provide lighting for farms and to charge batteries used to power crystal radio sets. But their use was extended to an entire array of direct-current motor-driven appliances, including refrigerators, freezers, washing machines, and power tools. But the more appliances were powered by the early wind generators, the more their intermittent operation became a problem. Figure 7. M.L. Jacobs adjusting the spring-actuated pitch change mechanism on a Jacobs Wind-electric in 1977. Slide 20: The demise of these systems was hastened during the late 1930s and the 1940s by two factors: the demand of farmsteads for ever larger amounts of power on demand, and the Great Depression, which spurred the U.S. federal government to stimulate the depressed rural economies by extending the electrical grid throughout those areas.
A lot is made of this development and how horrible it was for the government to intervene. (At this point in most wind energy documentaries, there's a plaintive whine of a harmonica and a shot of a rusting wind turbine hulk.) But I doubt the farmers who were helped by the new electrical grids would share this feeling. And the growing demand for electrical power created by the wind generator, combined with the inability of the technology to adapt, helped make the situation inevitable. The early success of the Midwest wind turbines actually set the stage for the possibility of more extensive wind energy development in the future. Slide 21: Bulk" Power from Wind
The development of bulk-power, utility-scale wind energy conversion systems was first undertaken in Russia in 1931 with the 100kW Balaclava wind generator.
This machine operated for about two years on the shore of the Caspian Sea, generating 200,000 kWh of electricity. Subsequent experimental wind plants in the United States, Denmark, France, Germany, and Great Britain during the period 1935-1970 showed that large-scale wind turbines would work, but failed to result in a practical large electrical wind turbine. Figure 8. Palmer Putnam's 1.25-megawatt wind turbine was one of the engineering marvels of the late 1930's, but the jump in scale was too great for available materials. Slide 22: The largest was the 1.25 megawatt Smith-Putnam machine , installed in Vermont in 1941.
This horizontal-axis design featured a two-bladed, 175-foot diameter rotor oriented down-wind of the tower. The 16-ton stainless steel rotor used full-span blade pitch control to maintain operation at 28 RPM. In 1945, after only several hundred hours of intermittent operation, one of the blades broke off near the hub, apparently as a result of metal fatigue.
This is not surprising considering the huge loads that must have been generated in a structure that had a lot in common with a gigantic rotating erector set Slide 23: In Germany, Professor Ulrich Hutter developed a series of advanced, horizontal-axis designs of intermediate size that utilized modern, airfoil-type fiberglass and plastic blades with variable pitch to provide light weight and high efficiencies.
This design approach sought to reduce bearing and structural failures by "shedding" aerodynamic loads, rather than "withstanding" them as did the Danish approach. One of the most innovative load-shedding design features was the use of a bearing at the rotor hub that allowed the rotor to "teeter" in response to wind gusts and vertical wind shear. Hutter's advanced designs achieved over 4000 hours of operation before the experiments were ended in 1968.
Post war activity in Denmark and Germany largely dictated the two major horizontal-axis design approaches that would emerge when attention returned to wind turbine development in the early 1970s.
The Danes refined the simple, fixed pitch, Gedser Mill design, utilizing advanced materials, improved aerodynamic design, and aerodynamic controls to reduce some of its shortcomings. The engineering innovations of the light-weight, higher efficiency German machines, such as a teeter hinge at the rotor hub, were used later by U.S. designers. Figure 10. Hutter's wind turbines, like other German devices of the mid-20th century, were advanced for their time. Why Wind? : Why Wind? Electricity! : Electricity! How much would it cost to run this 100 Watt bulb for a full day (24 hrs)? 100 Watts x 24 hours = 2400 Watt Hours (2400 Watt Hours = 2.4 Kilowatt Hours) 2.4 kWh x $0.08/kWh = $0.19 What about this 25 Watt CFL light bulb, which produces the same amount of light? 25 Watts x 24 hours = 600 Watt Hours (600 Watt Hours = 0.6 Kilowatt Hours) 0.6 kWh x $0.08/kWh = $0.05 More efficient light bulbs are great, but what is the BEST way to conserve electricity and reduce our consumption of fossil fuels???
TURN IT OFF!!!
Be conscious of your energy choices! This is strange because…Wind Energy is the Fastest Growing Energy Source in the World!! : This is strange because…Wind Energy is the Fastest Growing Energy Source in the World!! US installed capacity grew a WHOPPING 45% in 2007!!! Where do we get our electricity? : Where do we get our electricity? Why such growth…costs! : Why such growth…costs! 1979: 40 cents/kWh Increased Turbine Size
Manufacturing Improvements NSP 107 MW Lake Benton wind farm
4 cents/kWh (unsubsidized) 2004:
3 – 4.5 cents/kWh 2000:
4 - 6 cents/kWh Elegant Power Source 0f power : Elegant Power Source 0f power Wind energy Slide 33: Need to Change Perceptions… Wind Power : Wind Power Early “WINDMILL” in Afghanistan (900AD) : Early “WINDMILL” in Afghanistan (900AD) Jacobs Turbine – 1920 - 1960 : Jacobs Turbine – 1920 - 1960 Slide 39: Smith-Putnam Turbine
Vermont, 1940's Modern Windmills : Modern Windmills Orientation : Orientation Turbines can be categorized into two overarching classes based on the orientation of the rotor
Vertical Axis Horizontal Axis Vertical Axis Turbines : Vertical Axis Turbines Advantages
Accepts wind from any angle
Components can be mounted at ground level
Ease of service
Lighter weight towers
Can theoretically use less materials to capture the same amount of wind Disadvantages
Rotors generally near ground where wind poorer
Centrifugal force stresses blades
Poor self-starting capabilities
Requires support at top of turbine rotor
Requires entire rotor to be removed to replace bearings
Overall poor performance and reliability
Have never been commercially successful Types of Electricity Generating Windmills : Types of Electricity Generating Windmills Small (10 kW)
(e.g. water pumping, telecom sites, icemaking) Large (250 kW - 2+MW)
Central Station Wind Farms
Distributed Power Intermediate
Distributed Power Modern Small Wind Turbines:High Tech, High Reliability, Low Maintenance : Modern Small Wind Turbines:High Tech, High Reliability, Low Maintenance Technically Advanced
Only 2-3 Moving Parts
Very Low Maintenance Requirements
Proven: ~ 5,000 On-Grid
American Companies are the Market and Technology Leaders (Not to scale) Overspeed Protection: Furling : Overspeed Protection: Furling Wacky Designs out there… : Wacky Designs out there… Large Wind Turbines : Large Wind Turbines 450’ base to blade
Each blade 112’
Span greater than 747
163+ tons total
Foundation 20+ feet deep
Rated at 1.5 – 5 megawatt
Supply at least 350 homes Slide 50: North Wind HR3
rating: 3 kW
rotor: 5 m
hub height: 15 m North Wind 100
rating 100 kW
rotor: 19.1 m
hub height: 25 m Lagerwey LW58
rating: 750 kW
rotor: 58 m
hub height: 65 m Enercon E-66
rating: 1800 kW
rotor: 70 m
hub height: 85 m Boeing 747
wing span: 69.8m
length: 73.5 m Enercon E-112
rating: 4000 kW
rotor: 112 m
hub height: 100 m Comparative Scale for a Range of Wind Turbines Wind Turbine Technology Nomenclature : Nomenclature Working and use of wind turbine technology : Working and use of wind turbine technology Power generation Airfoil Nomenclaturewind turbines use the same aerodynamic principals as aircraft : Airfoil Nomenclaturewind turbines use the same aerodynamic principals as aircraft Slide 55: Blades Anatomy of a Wind Turbine Slide 56: Hub Anatomy of a Wind Turbine Blades Slide 57: Hub Anatomy of a Wind Turbine Blades Slide 58: Blades Hub Anatomy of a Wind Turbine € Anatomy of a Wind Turbine : Anatomy of a Wind Turbine Blades Hub Nacelle Yaw system Slide 60: Inside – Novel Nacelles (High Speed Generators) Slide 61: Inside – Novel Nacelles (Mid Speed Generators) Slide 62: Inside – Novel Nacelles (Direct-Drive Generators) Wind Energy Technology : Wind Energy Technology What works & what doesn’t Blade CompositionMetal : Blade CompositionMetal Steel
Heavy & expensive
Lighter-weight and easy to work with
Subject to metal fatigue Generation and transmission : Generation and transmission Village farming : Village farming Wind Farms in remote area : Wind Farms in remote area Wind farm : Wind farm Off-Shore Wind farms : Off-Shore Wind farms Middelgrunden : Middelgrunden Slide 75: 1980’s California Wind Farm
+ Higher RPMs
+ Lower Elevations
+ Poorly Sited
= Bad News! Industry Structure : Industry Structure Modern Approach in wind turbine technology : Modern Approach in wind turbine technology Concept used Wind Turbine Perspective : Wind Turbine Perspective Wind Power Today: Relative Height : Wind Power Today: Relative Height Empire Eiffel Umass 1.5 MW Medium Farm
State Tower Library Turbine Turbine Turbine
1250’ 986’ 297’ 356’ 212’ 142’
381 m 301 m 90 m 109 m 65 m 43 m
28 stories --------------examples ------------------- Relative height
of tall human
structures The importance of the WIND RESOURCE : The importance of the WIND RESOURCE Typical Wind Lessons - Not Technical : Typical Wind Lessons - Not Technical Beaufort Scale
All very interesting but very little of the science and technology related to the current wind industry is presented.
In fact most text books are pretty negative about the future of wind and misrepresent the technology miserably. Why do windmills need to be high in the sky?? : Why do windmills need to be high in the sky?? Importance of Wind Speed : Importance of Wind Speed No other factor is more important to the amount of power available in the wind than the speed of the wind
Power is a cubic function of wind speed
V X V X V
20% increase in wind speed means 73% more power
Doubling wind speed means 8 times more power Calculation of Wind Power : Calculation of Wind Power Power in the wind
Effect of air density,
Effect of swept area, A
Effect of wind speed, V R Swept Area: A = πR2 Area of the circle swept by the rotor (m2). Power in the Wind = ½ρAV3 Wind Energy Potential : Wind Energy Potential Key Issues facing Wind Power : Key Issues facing Wind Power Slide 91: In the November-December Audubon Magazine, John Flicker, President of National Audubon Society, wrote a column stating that Audubon "strongly supports wind power as a clean alternative energy source," pointing to the link between global warming and the birds and other wildlife that scientist say it will kill. Slide 92: May 1, 2002 Tax Incentives & Buydown Local Option Tax Incentives** Net Metering & Local Option Tax Incentives** Tax Incentives & Net Metering Tax Incentives, Net Metering & Buydown Net Metering & Buydown *Contact your utility to see if you qualify for the Renewable Energy Resources Program.
** Contact your city or county to see if they offer tax incentives for small wind systems. Net Metering Only Residential Small Wind Incentives Net Metering : Net Metering What does it take to install a Turbine? : What does it take to install a Turbine? Utility Engineers
Turbine Engineering (ME/EE/Aerospace)
Business Expertise (Financial)