Introduction

1. Impact of the Generation Addition at Red Bluff and Colorado River Stations on operation of EOR/WOR Paths

2. Introduction • Southern California Edison Co. (SCE) is currently constructing a 110 mile, 500 kV transmission line from SCE’s new Colorado River Substation near Blythe, California to SCE’s Devers Substation near Palm Springs, California • The name of the project is Devers – Colorado River (DCR) • Due to change of system configuration, SCE proposed Path 49 (EOR) and Path 46 (WOR) re-definition and upgrade • The Three Phase Rating Process conducted by SCE concluded that WOR is upgradable from 10623MW to 11200MW and EOR is upgradable from 9300MW to 9600MW

3. Map of Existing EOR Path

4. Map of Pre- and Post-DCR Project

5. Impact of the Future Generation Interconnecting Red Bluff and Colorado River Stations • SCE performed the Three Phase Rating Process and proved that due to system configuration changes with the addition of DCR, both Path 46 and Path 49 ratings can be increased • SCE performed a sensitivity study in order to show the impact of the future generation at Red Bluff and Colorado River on EOR and WOR • This sensitivity study showed that with the future maximum generation of 4000MW at Red Bluff and Colorado River, EOR cannot flow more than 5240MW • The CAISO explained that this kind of interaction will be resolved through the operating studies.

6. Impact of the Future Generation Interconnecting Red Bluff and Colorado River Stations • SRP has following concerns and questions: • Who identifies when interaction between new generation at Red Bluff and Colorado River and EOR creates congestion • What kind of mechanism will be in place between generation owners and EOR path operator in order to mitigate these problems and who gets curtailed first