1. Wind Energy 101
This slide show is a basic outline. We often make changes to this template depending on the time and location of the event.

2. Where do we get our electricity?2

3. Wind Energy is the Fastest Growing Energy Source in the World!!
The lack of cheap and easy lesson plans, kits and material is kind of strange as wind energy is the fastest growing energy resource in the world. For the last five years it has been growing at rate of 20-30%.
A bit misleading b/c when you start with a small amount it easy to grow fast. Nuclear, Coal and Oil could never grow at those rates takes too long to build and there is too much generation out there.
US installed capacity grew a WHOPPING 45% in 2007!!!

4. Look at the pie chart on the left.
Most of the wind energy generated in world is in Europe…next slide shows where. Americas (Canada, US, Mexico) accounts only for 15%...although this is increasing.

5. Note where wind energy projects are located….
CA, TX are the leaders…IA, MN and WA are the next batch….
Projects tend to be where the wind is located….not a whole lot in the SE

7. US installed capacity has fluctuate due to incentive that come into affect and then expire…hard to run a highly capitalized industry in this kind of environment. Things have been getting a little better. Last round of incentives will expire in December Some in congress want to extend this another 5 years.
One thing to explain here…
1 Megawatt of wind will generate enough power for about 300 homes. This depends on the type of device and where it is located.
Most large turbines that you see today are rated at 1.5 Megawatts…meaning that at peak output (high winds) it will be producing about 1.5 Megawatts

8. Why such growth…costs! 1979: 40 cents/kWh 2000: 4 - 6 cents/kWh
Increased Turbine Size
R&D Advances
Manufacturing Improvements
NSP 107 MW Lake Benton wind farm
4 cents/kWh (unsubsidized)
The rapid growth in wind power can be attributed to two things….reduction in cost of the electricity produced and more interested in Green Power.
I usually ask people here what they pay for their electricity by kwh….typical # are 7-20 cents. Wind has come way down in terms of cost over the last 40 years. The cheapest power out there is coal and wind cannot compete with that…Natural Gas and coal are comparable. The costs for wind listed above are the wholesale rate…do not include transmission etc.
On this slide I often ask the crowd how we generate most of our electrical power in the US.
Coal 50%
Nuclear 20%
Natural Gas 17%
Hydro 7%
Oil 3%
Renewables 3% Wind less than 1%
2004:
3 – 4.5 cents/kWh

9. Wind Energy: The Technology
This section talks about the history of wind turbines and the modern devices.

10. Early “WINDMILL” in Afghanistan (900AD)
First windmills were found in Persia.
They were vertical axis and were used to grind grains and seeds. They were kind of like a waterwheel turned on its side. Most of the paddles were covered by a wall and wind would run through a narrow opening to push the blades.

11. Many have seen the Dutch windmills
Many have seen the Dutch windmills. Used to grind grains, seeds, pump water, saw lumber…these were fairly sophisticated devices. Used to cover much of New England coastline.

12. Water pumpers were (and still are) a common site on farms in the Midwest and West. These devices pump water into a pond or cistern when it is windy and can be used at any time. Notice the blades on this device and compare them to electrical generating wind turbines are they the same or different?

13. Jacobs Turbine –
In 1888, Charles F. Brush invented a large wind turbine which created electricity. This enormous windmill produced enough electricity for about 10 homes. Brush’s invention was soon adapted and copied all over the world. Electricity generating wind turbines spread throughout Europe in the early 1900’s, and they soon appeared in the United States as well. In the 1930s Marcellus Jacobs producing an affordable small turbine called the Jacobs that provided electricity for homes and farms throughout rural America. However, these small American turbines faded away with the widespread installation of power lines through the end of the 1930s.

14. Smith-Putnam Turbine Vermont, 1940's
In response to fuel shortages, Palmer Putman was able to raise enough money to design and build a 1,250 kW wind turbine in Vermont in This was the largest turbine ever built and functioned for more than a year. But a bearing failure and lack of support (due to machinery shortages caused by WWII) caused maintenance to be overlooked. When the turbine was restarted in 1945 this lack of maintenance led to a catastrophic blade failure and the project never recovered.

15. Modern Windmills

16. Orientation
Turbines can be categorized into two overarching classes based on the orientation of the rotor
Vertical Axis Horizontal Axis
Turbine can spin on a vertical axis or a horizontal axis

17. Vertical Axis Turbines
Advantages
Omnidirectional
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

18. Lift vs Drag VAWTs Lift Device “Darrieus” Drag Device “Savonius”
Low solidity, aerofoil blades
More efficient than drag device
Drag Device “Savonius”
High solidity, cup shapes are pushed by the wind
At best can capture only 15% of wind energy

19. Horizontal Axis Wind Turbines
Rotors are usually Up-wind of tower
Some machines have down-wind rotors, but only commercially available ones are small turbines

20. Types of Electricity Generating Windmills
Small (10 kW)
Homes
Farms
Remote Applications
(e.g. water pumping, telecom sites, icemaking)
Intermediate
( kW)
Village Power
Hybrid Systems
Distributed Power
Large (250 kW - 2+MW)
Central Station Wind Farms
Distributed Power

21. Very Low Maintenance Requirements Proven: ~ 5,000 On-Grid
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
50 kW
10 kW
400 W
900 W
When teachers build their Basic PVC Turbines they are more like a small wind turbine, simple direct drive systems.
Emphasize high RPM…these things spin fast RPM.
Many of these are sent to villages offshore as they can provide power for an entire village…here in the US is hard to justify the cost for one household. $$ on small wind turbines 10K-100K
(Not to scale)

22. Close Up of a Bergey XL 1 a 1kW wind turbine
Close Up of a Bergey XL 1 a 1kW wind turbine. Produces 1000w at peak output.
For more info

23. Overspeed Protection: Furling

24. 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

25. US Large Wind Manufactures
General Electric
Clipper

26. Comparative Scale for a Range of Wind Turbines
Wind Turbine Technology
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
Enercon E-112
rating: 4000 kW
rotor: 112 m
hub height: 100 m
Boeing 747
wing span: 69.8m
length: 73.5 m
Scale of these devices….The largest wind turbines have a blade span much larger than a 747!!
Comparative Scale for a Range of Wind Turbines

27. A look inside.
Things to note as compared to Small Wind Turbines
Blades can be actively pitched by hydraulics. Spin at RPM --- much slower than a small wind turbine
Large driveshaft attached to a gearbox….must go from RPM to 1600 RPM for the generator.
Generator creates electricity.
Small Wind Turbines use vanes (typcally) to track the wind…they uses and anemometer and hydraulics to move the turbine.
Highly computerized and automated….senses conditions and can turn itself off if there is a problem.
Often connected by computers to one location and run from there.

28. Inside a Wind Turbine

29. Airfoil Shape
Just like the wings of an airplane, wind turbine blades use the airfoil shape to create lift and maximize efficiency.

31. Yawing – Facing the Wind
Active Yaw (all medium & large turbines produced today, & some small turbines from Europe)
Anemometer on nacelle tells controller which way to point rotor into the wind
Yaw drive turns gears to point rotor into wind
Passive Yaw (Most small turbines)
Wind forces alone direct rotor
Tail vanes
Downwind turbines

32. Wind farms are like powerplants…we wire a bunch of them together transform the current and put it on the power lines.
Some wind farms are very large 700MW that is as big as coal or nuclear power plant.

33. Wind Farms

34. Wind Farm in the MidWest

35. Windfarm 2
Windfarm in VT called Searsburg…one of the first windfarms in the Northeast. Wind farm development in VT is very contentious now in VT.. Notice the black blades. Why do they do that……to reduce ice build up in cold weather.
More info head tohttp://

36. Off-Shore Windfarms
Many developers would like to move windfarms offshore because the wind are faster, smoother and they can be close to major population centers on the coast. This is very controversial in the US….we have a few planned offshore farms…CapeWind and Long Island…but nothing installed.
Major complaints about offshore are related visual impact, navigation impact and lack of history.
Check

37. Middelgrunden
There are quiet a few offshore wind farms in Europe near Holland, England, Ireland, Sweden and the Denmark.
This one is off the coast of Copehagen.

39. Wind Turbine Perspective
Workers
Blade
112’ long
Nacelle
56 tons
Tower
3 sections

40. Twist & Taper
Speed through the air of a point on the blade changes with distance from hub
Therefore, tip speed ratio varies as well
To optimize angle of attack all along blade, it must twist from root to tip
Fast
Faster
Fastest

41. The importance of the WIND RESOURCE

42. Why do windmills need to be high in the sky??
The higher we get the more faster and cleaner the wind are.
As you move closer to the earth the friction with the surface of the earth causes the wind to slow down and to become more turbulent…bad things if you want to generate energy from the wind. The nacelle of most commercial wind turbines is around 100 meters.

43. Stuctures, tree anything in the path of the wind will create turbulence which can negatively affect wind turbines. This is why horizontal wind turbines should not be near your house, on your roof or in the middle of cities…too much turbulence.

44. Calculation of Wind Power
Power in the wind
Effect of air density, 
Effect of swept area, A
Effect of wind speed, V
Power in the Wind = ½ρAV3 R
This is the equation for the power in the wind. (Don’t fear – there are only 2 equations in this presentation.) Each of the terms in this equation can tell us a lot about wind turbines and how they work. Lets look at wind speed (V), swept area (A), and density (Greek letter “rho,” ) one at a time.
First, let’s look at wind speed, V. Because V is cubed in the equation, a small increase in V makes for a increase in power. (illustrated on next slide)
(Click on the links at the bottom to get the values of both k and .)
Swept Area: A = πR2 Area of the circle swept by the rotor (m2).

45. 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

46. Betz Limit
All wind power cannot be captured by rotor or air would be completely still behind rotor and not allow more wind to pass through.
Theoretical limit of rotor efficiency is 59%
Most modern wind turbines are in the 35 – 45% range

47. Wind Energy Potential

48. Notice where the winds are the strongest….
MN, ND, SD called the Saudia Arabia of windpower…if we saturated these state with wind turbine we could generate at most of energy used in the US…Why have we not done this? Tranmission is one major problem need to match load with generation…how would we get all the power out of there?
Why don’t we put lots of wind farms in the rockies? Lots of wind but very hard to get at 60 meter long blade to the continental divide….logisitics of these large machines is very challenging!

51. Wind Farms in Southwest Minnesota
Buffalo Ridge
Buffalo Ridge
Worthington, MN

52. Wind Farms in SW Minnesota
North Shaokatan MW
Shaokatan Hills MW
Lake Benton II MW
Viking MW
Chanarambie MW
Moraine MW
Woodstock MW
Buffalo Ridge MW
Ruthton MW
Lake Benton I MW
Lakota Ridge MW
Southwest Ridge Total = MW
Minnesota Total = 895 MW

54. Wind Potential
Source: U.S. DOE

55. Key Issues facing Wind Power

56. FACT:

57. 1980’s California Wind Farm
Older Technology
+ Higher RPMs
+ Lower Elevations
+ Poorly Sited
= Bad News!

58. 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.

59. Impacts of Wind Power: Noise
Modern turbines are relatively quiet
Rule of thumb – stay about 3x hub-height away from houses
Many people think wind turbines are noisy.
While this may have been true in the past (it is still somewhat true on older smaller devices)…newer larger devices are much quieter.
Go to Hull or Searsburg & listen!
Note: Searsburg turbines are
older & a bit louder than many modern turbines

60. Tax Credits No Federal Incentives for Small Wind Since 1985
Large Wind Supported with Production Tax Credit – 3 Yr. Renewal in the 2005 Energy Bill – EXPIRES END OF THIS YEAR!!!
States have varying levels of support
NY 50%-75% Support
ME 0%
MA 20%-50%
Wind Incentives:
Most of the incentives from the Federal Level are for large utility sized sytems…nothing is really enacted at the small wind at the federal level.
The Wind Energy Production Tax Credit (PTC), is a per kilowatt-hour tax credit for wind-generated electricity. Available during the first 10 years of operation, it provides 1.5 cents per kWh credit adjusted annually for inflation. The adjusted credit amount for 2005 is 1.9 cents per kWh. Enacted as part of the Energy Policy Act of 1992, the credit has gone through several cycles of expiration and renewal. The inconsistent nature of this tax credit has been a significant challenge for the wind industry, creating uncertainty for long term planning and preventing steady market development. In July 2005, the PTC was "seamlessly" renewed for the first time when an extension through December 31, 2007 was included in the federal Energy Bill. Just recently is was extended until 12/31/08…some legislators are looking for a 5 year extension on top of that.
The tax credit also is primarily useful for corporations and is difficult (but, not impossible) for other entities (farmers and individuals, schools, municipal utilities, etc.) to use effectively. (from Windustry).
States have varying levels of support from tax incentives, buydown, etc depending on where you live…

61. Residential Small Wind Incentives
This map is old….but it shows how there is a patchwork of incentives for small wind.
Some states offer buydowns, tax incentives and net metering others just offer net metering others offer nothing.
Some states like NY will pay for 50% of your system in approved location along with tax incentives etc.
There is a great database to research incentives for your state that is updated very regularly >>
May 1, 2002
Tax Incentives
Buydown*
Net Metering Only
Local Option Tax Incentives**
Tax Incentives & 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 & Buydown
Tax Incentives, Net Metering & Buydown
Tax Incentives & Net Metering
Net Metering & Local Option Tax Incentives**

62. Net Metering FROM AWEA.org
"Net-metering" is a simplified method of metering the energy consumed and produced at a home or business that has its own renewable energy generator, such as a wind turbine. Under net metering, excess electricity produced by the wind turbine will spin the existing home or business electricity meter backwards, effectively banking the electricity until it is needed by the customer. This provides the customer with full retail value for all the electricity produced.
Under existing federal law (PURPA, Section 210) utility customers can use the electricity they generate with a wind turbine to supply their own lights and appliances, offsetting electricity they would otherwise have to purchase from the utility at the retail price. But if the customer produces any excess electricity (beyond what is needed to meet the customer’s own needs) and net metering is not allowed, the utility purchases that excess electricity at the wholesale or ‘avoided cost’ price, which is much lower than the retail price. The excess energy is metered using an additional meter that must be installed at the customer’s expense. Net metering simplifies this arrangement by allowing the customer to use any excess electricity to offset electricity used at other times during the billing period. In other words, the customer is billed only for the net energy consumed during the billing period.

63. Transmission Problems
6.5 million customers
330+ generating units
Over 8,000 miles of transmission lines
11 Interconnections
28,100 MW of capacity
Peak demand: 22,544MW
One of the other major issues facing Commercial Wind Energy is transmission. It is typically windy where people don’t want to live so how will you get the power from where it is generated to where the people live? Most people oppose new power line construction vehemently….so this will be a touchy issue for a very long time.

65. Predicting Power Output
One major complaint about wind is that its power is intermittent. It comes and goes without notice…well this is not true…we can predict the weather and wind…
To deal with that issue wind engineers have teamed up with meteorologists to help improve the accuracy of predicting the windspeed so they can predict power output 2,4,8, 24 hours ahead of time. While not perfect this science is getting better and due to the nature of the grid if wind power plants can accurately predict power output the will act more like power plants.

66. Siting and NIMBY Where you site is a very big issue….
Many communities are wary of large wind farms being built in there communities…This can come from general grievances with the techololgy to perceived problems of noise, bird kills etc.
This image shows where they want to site the Cape Wind Offshore windfarm…this is a very contested project…about half the people on the cape support this the other half oppose.

67. What do you want in your backyard?
We also need to change students perceptions about what the future may look like and the limits of this technology.
Wind will never be “base load” for the grid. The wind farm above is capable of generating 15-20Mw of electricity at full capacity. The oil fired facility below is at 300Mw. Most Nuclear plants are at Mw…
Must keep the scale in mind….a very aggressive wind program can generate 10-20% of our power needs. To move towards a green future we are going to need mix of sources and also a great deal of energy efficiency….Wind cannot do it all.

68. Questions???

69. Joe Rand
The Kidwind Project