extra-high voltage

"Like most parts of the country, Indiana will see significant benefits from extra-high voltage transmission expansion.

"Building more extra-high voltage 765-kV transmission lines in Indiana can provide significant economic and environmental benefits.

Pooling critical energy apparatus in regions such as extra-high voltage transformers which can take months to manufacture and transport.

Copper is the preferred conductor material for underground transmission lines operating at high and extra-high voltages to 400 kV.

This type is useful at extra-high voltages, where phase conductors are bundled (two or more wires per phase).

Eon is selling almost 11,000km of extra-high voltage connections that pipe electricity from the North Sea to the Alps.

The turbine is linked to a 66 kilovolt floating power substation, the world's first according to the project operators, and an extra-high voltage undersea cable.

Bundle conductors, which are used for almost all extra-high voltage lines, are more susceptible to oscillations from wind forces than single conductors.

Towers for high- and extra-high voltage are usually designed to carry two or more electric circuits (with very rare exceptions, only one circuit for 500-kV and higher).

To continue reliable delivery of this energy and add the output of new generation that has been proposed in the state, Indiana needs additional extra-high voltage transmission capacity.

"AEP owns and operates the nation's largest transmission system, and we are the experts in building and operating extra-high voltage transmission.

This is particularly useful for high voltage cable and extra-high voltage cable applications, where degassing requirements can significantly lengthen cable manufacturing time.

In that incident, an energy industry association called the Western Systems Coordinating Council posted highly sensitive real-time data about transmission of extra-high voltage electricity in California.

Through the 50-50 partnership, AEP and Duke are proposing to build 240 miles of extra-high voltage 765-kilovolt (kV) transmission lines and related facilities in Indiana.

The combined projects encompass the first two phases of the Extra-High Voltage Overlay Study plan released March 3 by SPP.

AEP owns the nation's largest electricity transmission system, a nearly 39,000-mile network that includes more 765-kilovolt extra-high voltage transmission lines than all other U.S. transmission systems combined.

The EU executive said E.ON had offered to divest around 5,000 MW of generation capacity and committed to divest its extra-high voltage network.

"These extra-high voltage lines will not only help unlock the wind potential and opportunities for investment in Oklahoma, but also will provide a valuable renewable source of electricity to Oklahoma's utility customers."

The accelerating voltage for a television cathode ray tube may be described as extra-high voltage or extra-high tension (EHT), compared to other voltage supplies within the equipment.

The Commission in November 2008 ended an antitrust case against Eon after the German utility accepted to sell its extra-high voltage distribution network and a fifth of its power generation assets.

Extra-high voltage transmission inherently costs less and requires less land to carry the same amount of power than other transmission designs, and new 765-kV designs reduce line losses 40 percent over older designs.

These issues can be managed more successfully through strategic expansion of our nation's transmission grid, including significant investment in extra-high voltage transmission," said Michael G. Morris, AEP chairman, president and chief executive officer.

For high voltage and extra-high voltage networks underground cables were used (in the form of oil-filled cables) only in exceptional cases owing to their high cost in comparison with the equivalent overhead lines carrying the same electricity flow.

Southwest Power Pool's (SPP) estimated cost for the project is approximately $500 million based on SPP's Extra-High Voltage Overlay Study, but final costs will depend on the routing of the line, equipment and commodity costs.

The project is part of AEP's vision of expanded extra-high voltage transmission to improve the reliability of the nation's transmission grid, allow more efficient use of existing electricity production and delivery infrastructure, protect national security and expand opportunities for new generation, including renewables.