2025-2026 Transmission Planning Process, Phase 3 Competitive Solicitation: Bid window open; call on 6/24/26

The California ISO identified the transmission solution through the 2025-2026 transmission planning process, which was approved by the ISO Board of Governors on May 12, 2026. This transmission solution is now eligible for project sponsor selection in the Transmission Planning Process, Phase 3 Competitive Solicitation process as follows:

• Interested project sponsors must submit an application deposit and complete applications to finance, construct, own, operate, and maintain the Trout Canyon – Lugo 500 kV Line Project within the bid window, which runs from June 24 through Sep. 25, 2026.
• Entities interested in collaborating with another entity may notify the ISO prior to July 10, 2026.  If notified, the ISO will post a list on its webpage, including contact information, of entities interested in collaborating.  Project sponsors are not required to notify the ISO to collaborate. After the bid window closes, there will be no further opportunity to collaborate.

The project description, functional specifications and key selection factors for the competitive solicitation project is available on the 2025-2026 transmission planning process webpage.

The 2025-2026 Transmission Planning Process and Phase 3 Competitive Solicitation Schedule for these projects are available on the transmission planning process webpage linked above.

The Transmission Project Sponsor Application, which includes the instructions and data requirement descriptions, has been updated and will be available on the Transmission Planning webpage under the Transmission planning documents/Project sponsor documents subheadings. Project sponsors must use the most recent version of the application when preparing their proposal after the call.

Please submit complete applications, including the application deposit, as per the instructions in the Transmission Project Sponsor Application before the closing dates specified above. The ISO will acknowledge receipt of the application to the applicant within three (3) business days.

More information on Phase 3 of the transmission planning process is available in the Transmission Planning Process Business Practice Manual, which is available at the BPM Change Management webpage.

The ISO will hold a public stakeholder call on June 24, 2026, to discuss the Phase 3 Transmission Planning Process for the competitive solicitation projects. The purpose of the stakeholder call is to provide information to potential participants who want to better understand the process and projects currently eligible for competitive solicitation.

The stakeholder call will cover the following topics:

• Project functional specifications and key selection factors
• Submission of project sponsor applications
• Competitive solicitation process steps and schedule
• Matrix log of questions and answers

A presentation, as well as the schedule for these projects, will be available prior to stakeholder call on the process webpage linked above.

After the bid window opens on June 24, 2026, questions can be submitted to Transmission Competitive Solicitation at transmissioncompetitivesolicitation@caiso.com