WSP02437 - Laserfiche WebLink

Home Browse Search

I I I I I I I I I I I I I I I I I I I 67 weather resulted in high loads throughout the area. The minimum acceptable operating reserve for California Power Pool members is 7 percent. ADEQUACY OF THE TRANSMISSION SYSTEM The WSCC interconnected transmission system was generally adequate to accommodate firm and economy/surplus schedules during 1981. However, continuing transmission limitations were experienced in the Rocky Mountain Power Area and there were periods when economy/surplus schedules had to be curtailed throughout the region due to loop flDW as discussed in the next section. The transmission system interconnecting the Northwest and California areas was utilized extensively during 1981 setting records for both Northwest sales and for net deliveries, exceeding the previous record year (1976) by substantial amounts. A noteworthy amount of the power delivered to California came from Canadian sources. During 1981, the net energy transfer from the Northwest to California was 27,440 GWH. Addition of the Kinport-Midpoint 345 kV line and the Midpoint-Malin 500 kV line during the latter part of 1981 increased east to west transfer capability within the Northwest Power Pool Area (NWPP) by approximately 850 MW, increased transmission system reliability significantly, and made it possible to lift previous curtailment of resource transfers to Pacific Northwest load centers from the Jim Bridger coal-fired generating plant in Wyoming. In the Rocky Mountain Power Area (RMPA), the transmission system between Wyoming and Colorado continued to be stressed through the 1981 summer season and was operated at or above single contingency limits on occasion. During the 1981 fall season, the new Laramie River Station 345 kV lines to Ault and Story in Northern Colorado were placed in service. While these new lines have added to the transmission capability between Wyoming and Colorado, transmission limitations still exist on the follDwing transmission systems which will result in economy/surplus schedule curtailments and, on occasion, firm schedule curtailments: . Colorado to New Mexico/Arizona . Central Wyoming to Southwest and Northeast Wyoming . Western Colorado to Eastern Colorado . Wyoming to Colorado Utilities in the Rocky Mountain area have jointly established simultaneous operating limits and developed dispatching procedures to coordinate system operation within single contingency limits. IMPACT OF LOOP FLOW ON SYSTEM OPERATION During 1981, loop flow continued to create significant problems by limiting interarea transfers to less than desired levels. The major loop