April 9, 2024
Information Only
2022-2023 Transmission Planning Process, Phase 3 Competitive Solicitation: Revised Proposal Award Dates for Sequence 2 and Sequence 3 Projects

The California ISO identified three transmission solutions through the 2022-2023 transmission planning process, which were approved by the ISO Board of Governors on May 10, 2023.


Due to the complex nature of the proposals and complications in processing all three competitively bid projects under the original staggered schedule, the ISO is revising the award date of the Imperial Valley - North of SONGS 500kV Line and 500/230kV Substation, Sequence 2, Project and the North of SONGS - Serrano 500kV Line, Sequence 3, Project, by one and two weeks, respectively.


The award date for the Imperial Valley - North of Songs 500kV Line and 500/230kV Substation, Sequence 2, Project is revised from April 22, 2024 to April 29, 2024.


The award date for the North of Songs Serrano 500kV Line, Sequence 3, Project is revised from May 6, 2024 to May 20, 2024.


Section 24.5. of the CAISO Tariff defers the project evaluation process schedule to the ISO’s Business Practice Manuals (BPM).  The BPM for Transmission Planning Process, in Section 5.2, allows the ISO to update the originally posted schedule if circumstances necessitate a change.  The original staggered timelines were based on the ISO’s best estimates and prior experience.  However, the complexity of the proposals received for all three of the transmission projects necessitates an extension of the original timeline for the latter two phases of the staggered schedule to ensure the CAISO can complete a thorough comparative analysis of the bids.


The revised 2022-2023 Transmission Planning Process Phase 3 Sequence Schedule is available on the recurring process webpage.



Questions concerning the revised schedule can be submitted to Transmission Competitive Solicitation at

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