SDG&E TL623C San Ysidro to Otay Tap 69 kV

Evidence chain

1. 1

   Policy, planning or funding trigger

   CAISO approved reconductoring to raise the TL623C normal rating to 136 MVA at an estimated $5.4M, with a 2032 in service target, and stated that aged wood pole infrastructure requires detailed structural analysis.
2. 2

   Why this project is exposed

   The lower cost case assumes advanced conductor can be used without structure replacement on feasible sections, while the upper case assumes a full rebuild with standard conductor. SDG&E must provide analysis in the next planning cycle and seek CAISO approval for final scope.
3. 3

   Relevant TS capability

   Low weight, high capacity conductor that raises the rating on existing wood pole sections, supported by structural loading analysis and installation sequencing.
4. 4

   Is specification still influenceable?

   Yes. The decision is documented as open and the deciding analysis has not yet been filed.
5. 5

   Recommended commercial action

   Offer a pole by pole PLS CADD and structural feasibility comparison between TS and the standard conductor rebuild alternative.
6. 6

   Likely buyer

   SDG&E structural engineering and transmission planning, with CAISO approving final scope.
7. 7

   Key uncertainty

   How much of the route is overhead and feasible for reconductoring without structure replacement is not established at segment level.
8. 8

   Primary evidence

   • CAISO 2025 to 2026 Transmission Plan, Appendix H ProjectsISO planning document
   • CAISO Board Approved 2025 to 2026 Transmission PlanISO planning document