PJM Interconnection

PJM Interconnection LLC (PJM) is a regional transmission organization (RTO) in the United States. It is part of the Eastern Interconnection grid operating an electric transmission system serving all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and the District of Columbia. PJM, headquartered in Valley Forge, Pennsylvania, was the world's largest competitive wholesale electricity market until the development of the European Integrated Energy Market in the 2000s. More than 1,000 companies are members of PJM, which serves 65 million people and has 185 gigawatts of generating capacity. With 1,436 electric power generators and 85,103 miles of transmission lines, PJM delivered 783 terawatt-hours of electricity in 2021. Started in 1927, the pool was renamed the Pennsylvania-New Jersey-Maryland Interconnection (PJM) in 1956. The organization continues to integrate additional utility transmission systems into its operations. The Federal Energy Regulatory Commission (FERC) regulates PJM and approves its open access transmission tariff for the wholesale electricity market. In 1927 the Public Service Electric and Gas Company, Philadelphia Electric Company, and Pennsylvania Power & Light Company formed a power pool called the Pennsylvania-New Jersey Interconnection. The purpose of the power pool was to dispatch electric generating plants on a lowest cost basis, thereby reducing the electric costs for all members of the pool. After Baltimore Gas and Electric Company and General Public Utilities joined in 1956, the pool was renamed the Pennsylvania-New Jersey-Maryland Interconnection, or PJM. In 1996 - 1999 the FERC made a series of decisions which resulted in the restructuring of the U.S. electric utility industry. The FERC's intention in doing so was to open the wholesale power market to new players, with the hope that spurring competition would save consumers $4 to$5 billion per year and encourage technical innovation in the industry.