PJM staff seeks removal of planned U.S. mid-Atlantic power lines

Aug 8 (Reuters) - U.S. power grid operator PJM Interconnection said Wednesday its staff will recommend the removal of the Potomac Appalachian Transmission Highline (PATH) and the Mid Atlantic Power Pathway (MAPP) projects from PJM's regional transmission plans.

In a release, PJM, which oversees the grid serving 60 million people in 13 mid-Atlantic and Midwest states and the District of Columbia, said grid conditions have changed since the lines were originally planned.

"Our updated analysis no longer shows a need for the lines to maintain grid stability," PJM said.

Units of Ohio power companies American Electric Power Co Inc and FirstEnergy Inc proposed building the 765-kilovolt, 275-mile (442 km) PATH transmission line from West Virginia to Maryland for about $1.8 billion around 2007.

Washington power company Pepco Holdings Inc proposed the 500-kilovolt, 230-mile MAPP transmission line from Virginia to New Jersey for about $1.4 billion around 2008. The final project approved by PJM was smaller and would have run from Virginia to Delaware.

Both lines were already delayed, and in 2011 AEP and FirstEnergy sought to withdraw their application for PATH after PJM suspended the project.

The grid operator cited the slow economy, which reduced the growth of electricity usage, and its latest capacity auction, which added 4,900 megawatts (MW) of new generation and 14,833 MW of demand response resources.

Those new generation and demand response additions would more than offset planned retirements of about 16,000 MW of mostly coal-fired plants in PJM over the next few years due to environmental regulations.

PJM said its regional planning process looks 15 years into the future to determine what transmission upgrades will be necessary to keep power systems stable.

Since PJM's first regional transmission plan in 2000, the grid said its board has approved more than $24.3 billion in transmission upgrades.