CHARACTERISTICS

Wind turbines range in size from a meter to a hundred meters in rotor diameter and from a hundred watts to a thousand kilowatts in power output. Wind turbines suitable for residential or village scale wind power range from 500 watts to 50 kilowatts. Even though wind is an intermittent source, on a large grid it can contribute an estimated 15-20% of annual electricity production without special arrangements for storage, backup and load management.

The amount of energy in wind speed is proportional to the cube of the wind speed. While wind speed varies over time, it generally follows daily and seasonal patterns. Utility-scale wind power plants require wind speeds of at least 13 mph (6 meters per second). A 10 kW turbine located in a moderate wind regime can generate an average of 30 kWh of power each day. For large-scale projects, 12 months of consistent observation and recording is recommended for assessing wind resources.

Wind energy produces no GHG emissions. Thus, every kWh of electricity generated by wind technologies avoids the emissions associated with a similar number of fossil-fuel generated kWh.

Advances in the fields of aerodynamics and composite materials have helped reduce the costs of wind turbines, making modern electric power-generating wind turbines a reality. Utility interconnected wind turbines can generate power synchronous with the grid. These machines are economically attractive where there is a good wind resource and where the local power costs are in excess of 15 cents (or less) per kilowatt hour. State-of-the-art wind technology can operate with 98% availability, and today's turbines perform with capacity factors over 30%.

SIZE:
100-1000 kW_e (utility-scale); 1-50 kW_e (distributed power)

FEATURES:
Grid-connected or stand-alone uses, but availability is dependent on the presence of wind. Well-designed and well-maintained wind turbines at windy sites can generate 1000 kWh/m²/year.

COST:
$1,000-1,200/kW_e (utility-scale) (1992 dollars)
$1,900-2,200/kW_e (distributed, grid-connected)
$2,400-5,600/kW_e (distributed, battery storage)

Cost is very dependent on average annual wind speed, but under ideal conditions, electricity can be generated from wind for as little as $0.04/kWh, making wind competitive with conventional fuels.⁶

CURRENT USAGE:
Nearly 8,000 MW worldwide at end of 1997, although several thousand megawatts of additional projects have been proposed.

POTENTIAL USAGE:
Total worldwide wind potential is enormous; in China alone total wind energy potential is estimated at 250,000 MW.

ISSUES ASSOCIATED WITH IMPLEMENTING ACTION

• There is aesthetic opposition to wind because of noise while in operation and location of turbines. However, turbines can be located in rural areas, with surrounding land used for agriculture or other purposes.
• Birds are attracted to the whirring noises made by the turbines; in some areas bird mortality rates have increased significantly—in some instances affecting endangered species of birds.
• Resources are site-specific and may not be located close to demand centers.
• Wind is intermittent; if not grid connected, a source of back-up power is needed, increasing costs of generation.

CLIMATE CHANGE IMPACT

EMISSION EFFECT:
    

CONDITIONS FOR EMISSIONS MITIGATION:

• If wind potential reaches the projected 700-1,000 TWh worldwide by 2020, it would avoid the production of 0.1-0.2 GtC/year of fossil fuel-fired electricity.

EMISSION ESTIMATE:
1 kWh of wind avoids 0.5-1.0 kg/CO2 (~1-2 lbs/CO2) from conventional sources.
A wind turbine with a 500-kW capacity operating at 30% availability and producing 1.3 MWh per year avoids 351 MtC/year.

COST-EFFECTIVENESS:
$21.53 ton/C

SECONDARY EFFECTS:
Produces no air pollutants or greenhouse gases. Wind generation avoids up to 7 grams/kWh of SO, NOx and particulates from the coal fuel cycle (including mining and transport); 0.1 g/kWh of trace metals (including mercury); and more than 200 g/kWh of solid wastes from coal tailings and ash.

RESOURCES

• EPRI/DOE Utility Wind Interest Group (UWIG) is a utility organization that helps utilities evaluate the potential for wind generation in their service territory. UWIG also publishes a series of information brochures on technologies, costs, technical and environmental issues, resources, etc.
• The National Wind Technology Center provides a virtual library of wind-related technical publications. http://www.nrel.gov/wind/library.html

CONTACTS

American Wind Energy Association (AWEA)
Randall Swisher
Executive Director
Washington, DC
Tel: (202) 383-2500
http://www.igc.apc.org/awea/

European Wind Energy Association
London, United Kingdom
Tel: +44 171 402 7122
Fax: +44 171 402 7125
ewea@ewea.org
http://www.ewea.org/

National Renewable Energy Laboratory
Robert Thresher
Director, Wind Division
Boulder, CO
Tel: (303) 231-7199
http://www.nrel.gov/wind/

National Wind Coordinating Council (NWCC)
Janet Stone
Washington, DC
Tel: (202) 944-2300
Fax: (202) 338-1264

National Wind Technology Center
Golden, Colorado
http://www.nwtc.gov

U.S. Department of Energy
Office of Utility Technologies
Washington, DC
http://www.eren.doe.gov/wind/