Wind Power

Approximately 2% of the solar power that reaches the earth’s surface is converted into wind. Approximately 2% of the solar power that reaches the earth’s surface is converted into wind. This is ~30 times our present energy usage. This is ~30 times our present energy usage.

History Large sailing ships could generate hp. Large sailing ships could generate hp. Used extensively in Europe in the 19 th century Used extensively in Europe in the 19 th century Used for pumping water or grinding grain Used for pumping water or grinding grain Most rapid new development for generating electricity Most rapid new development for generating electricity

Early wind generators focused on single large generators Early wind generators focused on single large generators Grandpa’s Knob (Vermont) could generate up to 1.2 MW of power in the 1940’s. Grandpa’s Knob (Vermont) could generate up to 1.2 MW of power in the 1940’s. 200 ft diameter blades 200 ft diameter blades

New interest in wind electricity after oil embargo in New interest in wind electricity after oil embargo in Early NASA wind generator built in Ohio in 1975 could generate 100 kW of power in 18 mph wind using 125 ft long blade diameter. Early NASA wind generator built in Ohio in 1975 could generate 100 kW of power in 18 mph wind using 125 ft long blade diameter.

Boeing Mod 5B wind turbine on Oahu designed to generate 7.2 MW of electricity. Actually, produced 3.2 MW operating from Boeing Mod 5B wind turbine on Oahu designed to generate 7.2 MW of electricity. Actually, produced 3.2 MW operating from ft diameter on a 192 ft tall tower 420 ft diameter on a 192 ft tall tower Last government-sponsored project. Last government-sponsored project.

Many Different Styles Savonius Rotor Darius Rotor American multivane 2-Blade Wind Turbine 3-Blade Wind Turbine

Choice of style depends on application Multi-blade has good starting torque. Good for applications like pumps. Multi-blade has good starting torque. Good for applications like pumps. 3-blade has low starting torque but is more efficient at high rotation rates. Used for generating electricity 3-blade has low starting torque but is more efficient at high rotation rates. Used for generating electricity

Wind Farms Rather than using single large generator, we usually use several smaller generators to make wind farms Rather than using single large generator, we usually use several smaller generators to make wind farms

Practicalities Wind speed tends to increase with increasing height. Optimal height is ~300 m. Wind speed tends to increase with increasing height. Optimal height is ~300 m. Most commercial wind towers are 50 to 100 m high. Get ~80% of wind potential at this height. Most commercial wind towers are 50 to 100 m high. Get ~80% of wind potential at this height.

Power in the wind (Betz Limit) P=2.8310 -4 D 2 v 3 kW D is the diameter in meters v is the wind speed in meters per second D 2 - because area of windmill increases as D 2 v 3 - because KE in wind is proportional to v 2 and an additional v because of rate at which energy is brought to windmill

Maximum theoretical efficiency is 59% of the Betz limit. Maximum theoretical efficiency is 59% of the Betz limit. Modern wind generators are around % of maximum theoretical efficiency Modern wind generators are around % of maximum theoretical efficiency

You want to place wind generators in a location that get consistently high wind power.

Rated Output A wind generator has a rated power output a a particular wind speed, e.g. 10 kW at 20 mph. A wind generator has a rated power output a a particular wind speed, e.g. 10 kW at 20 mph. If wind speed drops so does power, e.g. if wind drops to 15 mph, P=(15/20) 3 10kW = 4.2 kW. If wind speed drops so does power, e.g. if wind drops to 15 mph, P=(15/20) 3 10kW = 4.2 kW. If wind speed increases, they usually feather the blades so they don’t generate too much power. If wind speed increases, they usually feather the blades so they don’t generate too much power.

Home Wind Power? HORNET - LOW WIND SPEED turbines with Split-Core PMA HORNET - LOW WIND SPEED turbines with Split-Core PMASplit-Core Hornet's are designed for class 3 to 7 or AVERAGE wind zones. Hornet's are designed for class 3 to 7 or AVERAGE wind zones. wind zoneswind zones Super low cost turbines! Super low cost turbines! 59" diameter blade 59" diameter blade MPH MPH 1200 Watts 65 MPH (under load) 1200 Watts 65 MPH (under load) ~$ ~$ Note at 11mph P=800/27=30W Note at 11mph P=800/27=30W

Globally averaged growth in wind power has been 34% for the last five years. Globally averaged growth in wind power has been 34% for the last five years. Goal: Have wind provide 5-10% of our electricity by (Currently it is ~2.3 %) Fall 2011: 43.5 GW installed (90 projects for another 8.5 GW under construction) Goal: Have wind provide 5-10% of our electricity by (Currently it is ~2.3 %) Fall 2011: 43.5 GW installed (90 projects for another 8.5 GW under construction) The EU was attempting to provide 20% by As of 2010, 84 GW ( turbines), which is 9.1 %. The EU was attempting to provide 20% by As of 2010, 84 GW ( turbines), which is 9.1 %.

as of June 2011

Illinois Energy Context Electric Profile (2009) Energy SourcePercent Total Coal43.4 % Petroleum0.05 % Natural Gas2.3 % Nuclear52.1 % Hydroelectric0.05 % Renewables1.9 % Data from the Energy Information Administration

Advantages Renewable Renewable No CO 2 or other emissions No CO 2 or other emissions Competitive price per kW-h Competitive price per kW-h Less than 1% of the land would be used for foundations and access roads, the other 99% could still be used for farming or other uses. Less than 1% of the land would be used for foundations and access roads, the other 99% could still be used for farming or other uses.

Advantages Diversify the predominantly coal and nuclear energy profile in Illinois and provide a hedge against rising energy costs Diversify the predominantly coal and nuclear energy profile in Illinois and provide a hedge against rising energy costs Every megawatt of installed wind capacity generates $1.7 million of investment Every megawatt of installed wind capacity generates $1.7 million of investment Renewable energy projects such as wind development contribute significantly to the local tax base Renewable energy projects such as wind development contribute significantly to the local tax base Each wind turbine can provide $2,000-$4,000 per year in lease payments thereby diversifying the income of farmers, ranchers and other landowners Each wind turbine can provide $2,000-$4,000 per year in lease payments thereby diversifying the income of farmers, ranchers and other landowners

Concerns About Wind Power Wind is intermittent so you don’t want to rely on it too much. ~15- 20% is considered safe. Wind is intermittent so you don’t want to rely on it too much. ~15- 20% is considered safe. Aesthetics: Actually more opposed to by people who don’t live near them. Aesthetics: Actually more opposed to by people who don’t live near them. Noise: New designs are very quiet Noise: New designs are very quiet

Concerns About Wind Power Bats & Birds Bats & Birds 30 % of first year bird deaths are due to collisions in nature30 % of first year bird deaths are due to collisions in nature interactions with humans and human- made objects cause many bird deathsinteractions with humans and human- made objects cause many bird deaths

Human Objects or Activity Number of Bird Deaths per Year Power Transmission Lines 130 – 174 million Collisions with Cars and Trucks 60 – 80 million Collisions with windows on buildings and homes 100 – 500 million Exxon Valdez oil spill About Collisions with Communications Towers 40 – 50 million Pesticides About 70 million

Human Objects or Activity Number of Bird Deaths per Year Cats million Jet engines, smoke stacks, and all other structures 300 – 500 million Altamont Pass, CA wind farm 92 San Gorgono Pass, CA 38 (out of 69 million in 1986 study) All wind farms 1.8 per wind turbine Migrating Bats 2 – 4 per turbine