PROBLEMS

The North Bay Area assessment found no normal problems during the study period. However, thermal overloads and low voltage problems could occur in the event of a single contingency. This is partially because of declining generation from the local geothermal units and because of very long 60kV circuits between the local main transmission substations and the scattered distribution substations. However, this emergency problem can be solved by having required RMR capacity in this area.

In the Eagle Rock pocket area, the outage of Cortina 230/115/60 kV transformer will yield unacceptable low voltage at the Covelo bus (Clear Lake area). RMR in this Eagle Rock area can correct this low voltage problem resulting from this contingency. A total of 224 MW is needed for year 2001 and this amount will grow as the load grows in future year. The total nameplate of RMR candidates is 327 MW, however the dependable capacity during peak load conditions is only 218 MW. There is a deficiency of about 6 MW in the RMR.

In the Fulton area, the loss of the Fulton-Ignacio 230 kV line with the overlapping outage of a large Geysers unit connected to Fulton (e.g., Geysers 11 or Geysers 16) would cause the Lakeville-Corona and Sonoma-Napa 115 kV lines to exceed their emergency ratings. It requires a total of 206 MW of RMR to eliminate the problem caused by this contingency for year 2001. The total nameplate of RMR candidates is 571 MW and the dependable capacity during peak loading conditions is only 271 MW.