Over $3bn will be spent on the upgrades to connect new generating facilities, while another $1.2bn has been allotted to a project in northern New Jersey, that seeks to address short circuit and thermal problems in that area.

PJM president and CEO Terry Boston said the transmission system is required to keep pace with the decommissioning of over 20,000MW of generation in the PJM region, and construction of new gas plants in various locations.

"The good news is that we continue to identify and approve projects needed to make the grid more reliable and resilient," Boston added.

Baseline reliability projects with a total estimated cost of $1.5bn has been identified in 15 different utility territories, some of which include construction of a new 500kV line within an existing right-of-way in the Dominion region, new substations in several regions to reinforce lower voltage systems, as well as additional upgrades to boost the grid reliability.

Some previously approved transmission projects have been canceled, due to the combined effects of other planned transmission upgrades, adjustments in annual load forecasts, generation retirements among others.

The canceled projects include the Toronto-Harmon 345kV line in FirstEnergy’s American Transmission System’s territory.