Electric Transmission and Transmission Facilities
Electric transmission is the process by which electricity is transported over long distances to consumers. New electric transmission facilities will be required for some new wind energy facilities.
Electric transmission is the process by which large amounts of electricity produced at power plants, such as industrial-scale wind facilities, is transported over long distances for eventual use by consumers. In North America, electricity is sent from power plants to the North American transmission grid, a network of electric transmission lines and associated facilities in the United States, Canada, and Mexico. Due to the large amount of power involved, and the properties of electricity, transmission normally takes place at high voltage (69 kV or above). Electricity is usually transmitted to a substation near a populated area. At the substation, the high voltage electricity is converted to lower voltages suitable for consumer use, and then transmitted to end users through relatively low-voltage electric distribution lines.
For newly constructed wind energy facilities, if no existing suitable transmission facilities are available, new transmission lines and associated facilities will be required. The construction, operation, and decommissioning of high-voltage transmission lines and associated facilities would create a range of environmental impacts. The type and magnitude of the impacts associated with transmission line construction, operation, and decommissioning would vary depending on line type and size, as well as the length of the transmission line, and a variety of other site-specific factors.
The main components of high-voltage electric transmission lines and associated facilities include:
Conductors (Transmission lines)
Conductors are the cables that carry the electricity to and through the grid to consumers. Generally, several conductors are strung on a tower for each electrical circuit. Conductors are constructed primarily of twisted metal strands, but newer conductors may incorporate ceramic fibers in a matrix of aluminum for added strength with lighter weight.
Rights of Way
Access routes to transmission structures for both line construction and maintenance are normally required, and may be paved or graveled. Vegetation clearing and recontouring of land may be required for access road construction. Additional temporary roads may also be needed during the construction and decommissioning phases of a transmission line project.
For More Information
More information about electric transmission and detailed descriptions of transmission facility components are available in the following technical report.