California ISO 2017-2018 transmission plan identifies 17 projects as needed to maintain reliability

The 2017-2018 California ISO transmission plan identified 17 transmission projects, having an estimated cost of about $271.3m, as needed to maintain the reliability of the ISO transmission system and provide for the economic operation of the grid, Keith Casey, vice president, Market & Infrastructure Development, said in his March 14 memorandum to the ISO Board of Governors.

Casey added that Management requests that the board approve seven reliability driven transmission projects identified as needed to ensure compliance with NERC and ISO planning standards and three economic-driven transmission projects. Those projects are in addition to the six reliability driven projects and one economic-driven project already approved by Management under its existing approval authority for projects costing less than $50m. None of those 17 projects are eligible for competitive solicitation, Casey added.

Other key findings and conclusions from the 2017-2018 transmission plan include that:

  • No policy driven transmission projects were identified as needed for meeting the 33% renewables portfolio standard (RPS) state policy objective
  • The third and final year of a major programmatic review of previously approved transmission projects in the PG&E service territory, given materially changed circumstances underpinning the original need for the projects, resulted in recommendations to cancel 18 transmission projects in the PG&E service area and major scope revisions to 21 projects, paring about $2.6bn from the current estimates of all previously approved projects. Further, Management recommends that seven projects in the PG&E service area remain or be placed on hold pending further review in future planning cycles
  • Two projects in the San Diego Gas & Electric (SDG&E) service territory are recommended to be canceled

“Based on the findings that the transmission solutions listed above are the most cost-effective, feasible solutions for meeting the identified transmission needs in the ISO system, Management recommends that the Board approve the attached ISO 2017-2018 transmission plan,” Casey added.

The ISO released a draft plan on Feb. 1 and presented it at a stakeholder session on Feb. 8. Casey also said that based on comments received from stakeholders, further revisions were made, culminating in the revised draft ISO 2017-2018 transmission plan.

Further discussing the key findings, Casey noted that the 13 reliability driven transmission projects that were identified as needed in this planning cycle to ensure compliance with NERC and ISO planning standards represent an investment of about $182.3m in infrastructure additions to the ISO-controlled grid.

Two of those, the Moorpark 230-kV circuit and the Oakland Clean Energy Initiative, are noteworthy in being part of comprehensive solutions including conventional transmission reinforcement and preferred resources, Casey said. The Moorpark project is part of the solution to allow the remaining once-through cooling generation in the area to retire on its compliance schedule, and the Oakland Clean Energy Initiative allows for the eventual retirement of the Oakland Generation Station. The Oakland Clean Energy Initiative is also one of two projects where the transmission plan includes selecting batteries to be procured as transmission assets to meet grid reliability needs – also a first for the ISO transmission planning process, Casey added.

According to the March 14 revised draft 2017-2018 plan, the “Moorpark-Pardee 4th 230 kV circuit” project is in the service area of Southern California Edison (SCE), has a cost of $45m, and is expected to be in service in December 2020. The revised draft plan also noted that the Oakland Clean Energy Initiative is in the PG&E service area, has a cost of $56m to $76m, and its expected in-service date is to be determined.

Casey said in the memorandum that the recommendations to cancel 18 projects in the PG&E service territory – as well as 21 projects requiring material scope modifications – reflect a number of changing circumstances from when the projects were approved several years ago, with the most significant changes mitigating the need for those projects being declining load forecasts as well as increased penetration of distributed renewable energy resources and their associated production profiles.

The ISO also identified seven other projects requiring further review in future planning cycles. Furthermore, Casey added, two previously approved reliability projects in the SDG&E area are recommended to be canceled – one of them, the Mission-Penasquitos project, was noted to be needing further review in the 2016-2017 Transmission Plan and the change resulted from the siting decision of the California Public Utilities Commission (CPUC) in approving the Sycamore-Penasquitos project.

According to the revised draft plan, the Mission-Penasquitos 230-kV circuit project was approved as a reliability project to mitigate the thermal overload concern on TL13810 Friars-Doublet Tap 138-kV line in the ISO’s 2014-2015 transmission plan. The expected cost of the project is $30m, the revised draft plan said, noting that the project would have utilized a de-energized portion of the Mission-San Luis Rey 230-kV line (TL23001) that would have been left behind after completion of the original Sycamore Canyon-Pensaquitos 230-kV project.

However, the CPUC recently approved an alternative line route that allows the new circuit go underground directly from Sycamore Canyon to Penasquitos substation. The revised draft plan added that the ISO reevaluated the need for the Mission-Penasquitos 230-kV circuit project in this planning cycle and did not identify the thermal overload concern on TL13810 Friars-Doublet Tap 138-kV line because TL23001 remained unchanged. In addition, the ISO’s further evaluations did not recognize a negative impact on generation deliverability or the local capacity requirement in the area; therefore, the ISO is recommending canceling this project, the revised draft plan said.

Casey noted in the memorandum that four upgrades were found to be needed as economic-driven projects in the 2017-2018 planning cycle:

  • The S-Line Upgrade, providing congestion and local capacity benefits
  • The Bob to Mead 230-kV Line Upgrade, providing congestion benefits
  • Two South Bay-Moss Landing enhancements comprised of the San Jose-Trimble 115-kV series reactor and the Moss Landing-Panoche 230-kV Path Upgrade, providing local capacity benefits

According to the revised draft plan:

  • The “IID S-Line Upgrade” is in the SDG&E service area, has a project cost of $50m, and is expected to be in service in December 2021
  • The “Bob-Mead 230 kV Reconductoring” project is in the VEA service area, has a project cost of $25m, and is expected to be in service in December 2020
  • The “San Jose-Trimble 115 kV line limitation and consideration of series reactors” project is in the PG&E service area, has a project cost of $6m to $9m, and is expected to be in service in May 2019
  • The “Moss Landing-Panoche 230 kV Path Upgrade” is in the PG&E service area, has a project cost of $5m, and is expected to be in service in December 2018

Casey noted in the memorandum that each year, the ISO undertakes a comprehensive assessment of the transmission needs of the system over a 10-year planning horizon and produces an annual transmission plan. Casey said that the ISO 2017-2018 plan provides a comprehensive evaluation of the ISO’s transmission grid to identify upgrades needed to successfully meet California’s policy goals, in addition to examining conventional grid reliability requirements and transmission projects that can bring economic benefits to consumers.

The number and capital costs of recommended transmission projects in the 2017-2018 plan represent a modest increase from the low amounts experienced in recent years, Casey said, adding that while the previous lows were due to the considerable progress made in earlier planning cycles in identifying and approving a wide array of transmission projects, emerging issues and evolving economic opportunities as well as localized load growth have led to more development being identified in this cycle.

However, policy driven transmission has not played a role in this year’s plan as earlier cycles addressed the policy driven transmission needs to achieve a 33% RPS. Casey added that while California Senate Bill 350, the Clean Energy and Pollution Reduction Act of 2015, which was signed into law in October 2015, established among other goals a 50% RPS by 2030, the implementation details for achieving the goal are not yet ready to inform transmission planning approvals.

About Corina Rivera-Linares 3286 Articles
Corina Rivera-Linares was TransmissionHub’s chief editor until August 2021, as well as part of the team that established TransmissionHub in 2011. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial from 2005 to 2011. She has also covered such topics as health, politics, and education for weekly newspapers and national magazines.