Welcome to the American Transmission Systems, Incorporated (ATSI) home page. On September 1, 2000, ATSI became the first electric transmission subsidiary of an investor-owned utility in the United States. FirstEnergy Corp. transferred ownership and control of the transmission system assets of its electric utility operating companies - The Toledo Edison Company (Toledo Edison), The Cleveland Electric Illuminating Company (The Illuminating Company), Ohio Edison Company (Ohio Edison), and Pennsylvania Power Company (Penn Power) - to ATSI, a wholly owned subsidiary of FirstEnergy.

Effective October 1, 2003, ATSI transferred operational control of its transmission facilities to the Midwest Independent Transmission System Operator (Midwest ISO). With this transaction, ATSI's control of those functions and activities contemplated by FERC in its Order No. 2000 to be undertaken by a PJM Interconnection Regional Transmission Organization (RTO) will be performed by the Midwest ISO.

ATSI owns major, high voltage transmission facilities, including approximately 7,100 circuit miles of transmission lines with nominal voltages of 345 kV, 138 kV and 69 kV. There are 37 interconnections with six neighboring control areas. ATSI's transmission system offers gateways into the east via high capacity ties with Pennsylvania Electric Company (Penelec), Duquesne Light and Allegheny Power, the north through multiple 345 kV high-capacity ties with Michigan utilities (MECS), and to the south through ties with American Electric Power and Dayton Power & Light. With its affiliation with the Midwest ISO, ATSI plans, operates, and maintains its transmission system in accordance with North American Electric Reliability Corporation reliability standards, and applicable regulatory agencies to ensure reliable service to customers.

FirstEnergy transmission planning criteria (pdf)

(05/28/09)