PJM's analysis said the project wasn't needed until 2014.
Friday's filing starts a 400-day clock for the PSC's review and decision, said agency spokeswoman Sarah Robertson. The agency is expected to hold public hearings while it reviews the application.
The filing comes as Eastern Panhandle residents planned a May 31 protest. Kerwyn Newcom and Patience Wait planned to take advantage of routine traffic jams on U.S. 340 to protest the line's proposed route through Jefferson County. The highway is often congested by weekend motorists traveling to fish or canoe the Potomac River or visit Harpers Ferry National Historical Park.
As envisioned, PATH would travel from AEP's John Amos power plant in western West Virginia to a substation in Frederick, Md. The line would cross central West Virginia before passing through Clarke, Frederick and Loudoun counties in Virginia. The line then crosses back into West Virginia before ending in Maryland.
"We understand the concerns about the impact of transmission lines and will work with the states and landowners to address concerns," Michael Morris, AEP's chairman, president and chief executive, said in a prepared statement.
The West Virginia Highlands Conservancy said Friday the transmission line would promote the use of coal as an energy source, ruin scenic vistas and increase utility rates for customers.
Last month, the state Supreme Court rejected similar arguments when it decided not to interfere with a separate high-voltage line Allegheny Energy proposes to build through northern West Virginia.