Creating Electricity from the Wind In addition to teaching about wind power because of it’s growth in the US I find it to be an elegant source of power as do students when they try to build their own spinning devices. Solar boring….just sits there;-) I will often tell a story about the Research done by Smart Power SmartPower research is based on the fact that studies continue to show consumers are willing to switch and pay more for renewable energy, yet there is minimal market activity to date. SmartPower wanted to understand what are the emotional barriers which prevent people from purchasing clean energy and what are the most powerful emotional hooks that could make clean energy important and desirable to the American public?   SmartPower brought together focus groups to explore how the public perceives current energy choices. Participants were charged to write an obituary. Respondents were asked to imagine fossil fuels on earth have died. Their task is to then to write an obituary including: What was the cause of death? What will it be remembered for? Who will take its place? Who will miss it? They found that many people were far less critical of fossil fuels than you might have imagined. Many felt it was scary to imagine our world without fossil fuels.  While many participants clearly recognized the problems of pollution, health and energy independence, they see fossil fuels as a necessary evil because it can be relied on to power our world. They also did not know about reliable alternatives. While they were all comfortable discussing clean energy and know how it’s made -- they don’t see it as “being up to the job” and is viewed as “eccentric” with “kinks to work out.” Next, they asked respondents to draw what their “clean energy” world would look like and to name their “worlds” and date them. The pictures reinforced the prior findings; fossil fuels are viewed as a necessary evil -- bad for health, bad for the environment, bad for national security. But at the end of the day, it keeps my house warm. Some other findings were that: Clean energy is simply not seen as up to the job Using clean energy would require sacrifices Clean energy is just too far in the future to be useful now As the obituaries and the drawings tell us we need to convince people that clean energy is strong enough to take the place of coal, oil and nuclear. They also found that we need to inform consumers that these sources are available and happening now. From this research came an advertising campaign that tries to convince people that clean energy is viable and available. The slogans, ads and radio spots created by this research is called Clean Energy: Its Real. It’s Here. It’s Working. Let’s Make More. Now SmartPower is doing research to see if this campaign changes any peoples mind about renewable energy choices. Elegant Power Source

KidWind Project | www.kidwind.org Wind Power History Electricity Generation Where in the US Pros and Cons Technological Issues KidWind Project | www.kidwind.org

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.

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.

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?

Jacobs Turbine – 1920 - 1960 WinCharger – 1930s – 40s 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.

Modern Windmills

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

Part of a turbine…all turbines from our little models to the biggest in the world have these parts.

A look inside. Things to note as compared to Small Wind Turbines Blades can be actively pitched by hydraulics. Spin at 12-20 RPM --- much slower than a small wind turbine Large driveshaft attached to a gearbox….must go from 12-20 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.

KidWind Project | www.kidwind.org The “guts” of a wind turbine KidWind Project | www.kidwind.org

Energy Transformations Kinetic Energy in the Wind  Kinetic Energy in the turbine  Magnetic Energy in the motor  Electric energy (electricity) KidWind Project | www.kidwind.org

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

KidWind Project | www.kidwind.org

KidWind Project | www.kidwind.org

KidWind Project | www.kidwind.org

Why such growth…costs! 1979: 40 cents/kWh 2000: 4 - 6 cents/kWh NSP 107 MW Lake Benton wind farm 4 cents/kWh (unsubsidized) Increased Turbine Size R&D Advances Manufacturing Improvements 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

Key Issues facing Wind Power

Need to Change Perceptions… 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 600-1000Mw… 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.

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. National Audubon Society endorses wind power…

Wildlife Impacts When siting a wind farm, developers must consider any possible wildlife impacts. Though this was not the case in early wind farm development (1980’s), today all proposed wind farms must undergo a strict environmental impact assessment.

It is a common complaint that wind turbines kill birds It is a common complaint that wind turbines kill birds. While it is true that turbines kill birds, this graph puts that in perspective with other human technologies.

1980’s California Wind Farm Older Technology + Higher RPMs + Lower Elevations + Lattice Towers + Poorly Sited = Bad News! Altamont Pass Wind Farm in California… This wind farm was built in the 1980’s. Without doing an Environmental Impact Assessment, they built the wind farm in a raptor migration path. This wind farm had a major problem with avian mortality, and scarred the industry. Today this farm is being repowered. This means they are taking down the old turbines and replacing them with new. With one new turbine, they can replace 10 old turbines. Still poorly sited, but this is an improvement.

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.

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.

Transmission Problems Where is the wind? Where are the population centers? Where are the wind farms? How do we get wind energy from the wind farms to the population centers? Probably the largest issue 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. Quick Fact: 1 mile of High Voltage transmission line can cost upwards of $1 million!

Energy Storage Wind is inconsistent Wind must be just the right speed Battery storage lags behind technology Leads to reduced political interest in wind Probably the largest issue 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. Quick Fact: 1 mile of High Voltage transmission line can cost upwards of $1 million!

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

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 Centripetal 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 (large scale)

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 Proven, viable technology

Various small HAWTs 1. Southwest Skystream 2. Bergey 3. ARE (now Xzeres) Check out http://www.smallwindcertification.org/index.html

Wacky Designs out there… Over-road design is an artist rendering.. Lots of engineering/design excitement in this industry.

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

What blade designs cause the maximum amount of energy to be produced What blade designs cause the maximum amount of energy to be produced?Brainstorm these on your worksheet.

Create a controlled experiment: What design aspect do you want to check? (independent variable) What design aspects do you need to hold constant? (controlled variables) What will you be measuring? (dependent variable) What is your hypothesis about how changing the independent variable will affect the dependent? On what prior knowledge are you basing your hypothesis?