Independent System Operator (ISO) (ISO)

The ISO is an evolving concept. In general usage, an ISO is a voluntarily-formed entity that ensures comparable and nondiscriminatory access by power suppliers to regional electric transmission systems. As currently envisioned, ISOs would be governed in a manner that renders them "independent" of the commercial interests of power suppliers who also may be owners of transmission facilities in the region. The ISO assumes operational control of the use of transmission facilities, administers a system wide transmission tariff applicable to all market participants, and maintains short-term system reliability. ISOs will develop on a regional basis, reflecting differences among regions in operating and structural characteristics of the transmission grid. Some ISOs also may be responsible for long-range system planning.