TEPPC 2026 Common Case
California Once Through Cooling Assumptions
November 3, 2015
OTC Replacement Assumptions for Southern California
A year has passed since the Data Work Group (DWG) last visited SONGS and OTC resource
replacement assumptions in the TEPPC database making this year’s update go much
smoother. David Le from the ISO took a first pass at updating the assumptions last agreed in
the TEPPC 2024CC using recent information from ongoing LTPP proceeding for the PPTA,
Tracks 1 and 4.
Accordingly, DWG met on September 1 to hear more about how some pieces of the puzzle are
coming together such as the procurement selection from SCE as well as the CPUC’s recent
Decisions on the Carlsbad Energy Center for SDG&E. (The commission’s authorization for
preferred resources was high level). Additional work was deemed necessary to reflecting recent
information that covered:
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SCE’s Ex Parte Communication with CPUC.
CPUC Decision on SDG&E’s Power Purchase Agreement (PPA) with Carlsbad Energy
Project (CEP).
SDG&E’s long-term expectation for energy storage additions in the San Diego area
Jan Strack further reviewed and edited David’s table to reflect assumptions agreed to by
meeting participants:
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Incremental EE to use
Additional Achievable Energy Efficiency (AAEE) assumptions making consistent with the
CEC forecast
Added 99 MW of generic preferred resources + storage in the LA Basin in order to reach
the CPUC-specified minimum procurement authorization for preferred resources +
storage based on a recommendation made by Keith White.
OTC Replacement Assumptions for Northern California
Relative to Northern California OTC assumptions, David Le had suggested using
assumptions from Table 4-4 of the ISO 2015-2016 Transmission Planning Process
Unified Assumptions and Study Plan (http://www.caiso.com/Documents/2015-
2016FinalStudyPlan.pdf). David noted that Morro Bay has a process in place.
Relative to Diablo Canyon, there are alternatives for cooling systems that were
evaluated by the consultants to the utility and the State Water Resources Control Board
(SWRCB). The review process, especially in the Special Studies Final Report, remains
on-going at the SWRCB. David indicated that in ISO studies, the plant is on-line in
2025 and is modeled as base loaded resource.
Jamie Austin, DWG
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Relative to Moss Landing, Angela shared that the CEC used de-rated capacity values:
85% + 10MW for both units, as of 2021. David agreed with Angela’s suggestion of
adding the NQC de-rate of 10MW, a 10% de-rate.
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Units 6 and 7 will retire 12/31/2020
Moss Landing Units 1 and 2 will continue operating. However these will begin operating
1/1/2021 with a 15% capacity de-rate due to some type of parasitic load that will allow
those two units to be in compliance.
In a follow-up meeting on September 15, concerns relating to Energy Efficiency and Demand
Response were discussed and a recommendation was developed to their treatment in TEPPC
modeling.
Jamie Austin, DWG
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