Independent System Operators (ISO) grew out of the Federal Energy Regulatory Commission (FERC) Orders Nos. 888/889 where FERC suggested the concept of an Independent System Operator as one way for existing power pools to satisfy the requirement of providing non-discriminatory access to transmission. Subsequently, in Order No. 2000, FERC encouraged the voluntary formation of Regional Transmission Organizations (RTOs) to administer the transmission grid on a regional basis throughout North America (including Canada). Order No. 2000 delineated twelve characteristics and functions that an entity must satisfy in order to become an RTO.
Indiana has two (2) RTOs in which our utilities are members: MISO and PJM. All electric utilities are members of MISO except for American Electric Power (AEP) d/b/a Indiana-Michigan Power (I&M) who is a member of the PJM Interconnection (PJM). Membership in RTOs is voluntary. Below is a graphical depiction of the North American Grid Operators. Tan-shaded areas do not have membership in any RTO/ISO.