TANC is currently planning an upgrade of the California-Oregon Intertie (COI) which consists of the California-Oregon Transmission Project (COTP) and the two Pacific AC Intertie lines. Modifications to these COI facilities will result in a 300-MW upgrade to the COI rated transfer capability.
The California-Oregon Transmission Project (COTP or Project) consists of 340-miles of 500-kV transmission line that interconnects with the Bonneville Power Administration (BPA) at the BPA Captain Jack Substation in Southern Oregon and with Pacific Gas and Electric Company (PG&E) in California at the Tesla Substation near Tracy, and the Los Banos Substation near Los Banos.

In commercial operation since March 17, 1993, the COTP is an integral part of the California-Oregon Intertie (COI). The Project is rated at 1600-MW and consists of two substations (Olinda and Tracy), and one series-compensation station (Maxwell).

The Olinda Substation near Redding, California includes facilities to interconnect the Project to the Western Area Power Administration’s (Western) 230-kV transmission system through an 850-MVA transformer bank. At Tracy Substation, there are two similar transformer banks interconnecting the Project to Western, each of which has a capacity of 850-MVA.

The COTP participants include TANC, Western, PG&E, City of Redding, Carmichael Water District, and San Juan Water District.  The Project has been operating reliably since being placed in operation. Operations and maintenance services are provided by Western.