Pjm is the largest power grid operator in the united states, serving 67 million customers from chicago to new jersey. [4] pjm, headquartered in valley forge, pennsylvania, was the world's largest รขโ‚ฌยฆ In 2025, pjm collaborated with its stakeholders to consider and act upon modifications needed to keep pace with the changing grid and ensure that reliable electricity continues to be delivered cost-effectively.