Allegheny Energy, Inc., Greenburg, PA, announced that PJM Interconnection has approved a major expansion of the company's 500-kV electric transmission system.The PJM board has approved a five-year program designed to maintain the reliability of the transmission grid in the Mid-Atlantic region. The plan, which was proposed in a regional planning study released by PJM in May, includes construction of approximately 210 miles of 500-kV transmission lines within Allegheny's service territory.

Specifically, the plan calls for construction of a new 500-kV line extending from southwestern Pennsylvania to West Virginia to northern Virginia. The project has a targeted completion date of 2011. Preliminary cost estimates for Allegheny's portion of the project and other upgrades are in excess of $850 million.

Allegheny will now begin line siting and permitting. In addition, Allegheny will seek regulatory approvals from the utility commissions in states the line crosses. Also, Allegheny has requested incentive rate treatments from the Federal Energy Regulatory Commission, and requested that the U.S. Department of Energy designate the project as a National Interest Electric Transmission Corridor.