EXPLAINER | Keeping the lights on: the PJM Interconnection
22 stories

Keeping the lights on: the PJM Interconnection

This map shows PJM's territory. It serves 61 million people.

This map shows PJM's territory. It serves 61 million people.

The PJM Interconnection is the regional transmission organization serving Pennsylvania’s electric market.

Its main function is to act as a neutral party for the movement of wholesale electricity– essentially to “keep the lights on” and ensure a reliable grid.

About 21 percent of the nation’s gross domestic product (GDP) is produced within PJM’s territory.

It serves 61 million people and covers all or part of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia.

PJM’s authority does not extend into retail electric markets. In Pennsylvania, that’s the role of the state’s Public Utility Commission.



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