History of Wind Power

Large Wind Systems  Range in size from 100 kW to 2 MW  Provide wholesale bulk power  Require 13 mph average wind sites

Technology Overview - Large Wind Projects  Projects operating at greater than 35% capacity factors at good wind sites  Over 98-99% availability  Select projects are delivering power ~ 3 cents/kWh (with Production Tax Credit)

Cost of Energy - Large Wind Projects Levelized Cost of Energy (cents/kWh)

Fastest Growing Energy Source in the World Global growth by energy source, annual average Source: Worldwatch Institute 2000

Taking Off Worldwide Wind Leaders: 1. Germany 2. United States 3. Spain 4. Denmark 5. India Total (end of 2000): nearly 17,000 MW Based on information supplied by International Energy Agency.

2000: A Year for Market Innovations  Several companies begin selling green power certificates  Several states see first large- scale wind power project: PA, NY, TN  Texas RPS fuels building boom

2001: Wind Power Expected to Take Off  US Wind Capacity expected to nearly double by the end of 2001  The Northwest will see the largest US wind project to date with the Stateline Wind Farm (300 MW)

An All American Resource Rank State North Dakota Texas Kansas South Dakota Montana Nebraska Wyoming Oklahoma Minnesota Iowa Colorado New Mexico Idaho Michigan New York Illinois California Germany’s Potential: 100 GW North Dakota’s Potential: 250 GW World Class Wind Potential

Drag Device

Giant Brush Windmill (1887 – 1900s)  Charles Brush  Automatically operated  Dynamo  Charged batteries  Provided light

Earliest Use  May be sail boats  Persia A.D. - Drag, Vertical Axis Device - Panemone - Grain Grinding & Water Pumping  China 1219 A.D. - Grain Grinding & Water Pumping  Crete - Water pumping for livestock.

 Horizontal Axis with Sail Wings  Higher Efficiency  Wooden Cogs and Ring Gears to Transmit Power. Windmills of Western World (1270 Mediterrean Coast)

 Water Pumping Windmill  Pumping water for livestock.  Relatively light, steel blades with aerodynamic shape.  Blades hinged to fold in high winds.  Tail to track wind direction. Halladay Fan-Type Windmill (1854 in U.S.)

Windmill with Pitch Change Mechanism

Palmer Putnam’s Windmill

Darrieus Machine (1973)  NASA sponsored research during oil crisis.  No tower and major equipment at ground level.  Marketed by Flo Wind  Failed to withstand forces during high winds  Never caught on.

Early, Large Large 2 MW Machine (Early 1980s.)  Developed by NASA.  Response to problem with downwind machine of Ulrich Hutter.  Large loads.  Noisy. Interfered with communications.  Tested in Boone, NC and Hawaii.

Another Early MW Machine

Federal Wind Test Center ( )  Tested Small & Intermediate Wind Turbines  Culled bad designs.  Bergie Design is spinoff.  UTRC's Composite, Flexbeam Rotor  NREL assumed control in 1989.

Danish Machines (1942)  F.L. Smidth early designs  Three Blade Upwind Machine  Hybrid wind & diesel systems.  DC Generator

Vester Egesborg Turbine (1950s)  Johannes Juul  Student of Poul La Cour  First ac machine.

Gedser Wind Turbine ( )  Johannes Juul  Electromechanical Yawing  Asynchronous Generator  Stall Controlled  Special brakes for overspeed conditions.

The Riisage Turbine

Competing Turbine Engines

The Tvind 2 MW Machine

Bonus 20 KW

Danish Domination of 1990s  Slow, steady growth in Europe & Asia  Mid-range machines  Reliable with high availabilities.  Conservative, Lower Efficiency  American Company - Zond emerged  Green Power, State RPS program, & Tax credits kick- started American Market in late 1990s.

Great California Wind Rush (1980s)  Tax Credit based on installed capacity.  Lots of bad wind turbines installed.  Lot of turbines were inoperable and had high O&M.  Conservative, Danish machine emerged.

Avedore Wind Farm, Denmark

Middelgrunden Wind Farm

Tuno Knob Offshore Wind Farm

Vindeby Wind Farm

TVA History  In 1980s Tested a 2 MW machine. – numerous problems Tested small machines at various locations. Conducted extensive siting  2000 Re-examined earlier work Meso scale computer modeling Sodar development Monitoring Walk-throughs  October 2000 Commissioned 2 MW project on Buffalo Mountain

Future of Wind Power  Expect cost to continually drop ($0.02/kwh by 2010) Taller towers Increased efficiency, less expensive blades – wood composite Drive trains – Direct drive – Power electronics Revolutionary change – The Wind Power Company down 2 blade machine Larger size (1.5 – downwind 3.0 MWs)

Future of Wind Power - continued  AWEAs estimates 100,000 MW in USA by  Transport of wind power from plains states.  Off shore wind development

Future for the Tennessee Valley  Taller towers  Self erecting towers  Different Power Test procedures  Sodars for wind resource measurements  Low wind speed turbines  Energy storage

TVA’s Plans  RFP for wind power on Buffalo Mountain.  Online by December  Prefer Power Purchase Agreement.  Expansion for Green Power Switch.  May partner with neighboring utilities.