California's grid operator has scheduled a stakeholders conference call for Thursday to discuss the draft proposed tariff for implementing the second phase of the state's natural gas-electric coordination plans assuming continued closure of the Aliso Canyon natural gas storage field.
The proposed tariff for the winter reflects the California Independent System Operator's (CAISO) proposal to extend certain mitigation measures approved by FERC early in the year for use during this past summer. CAISO plans to file the tariff with the Federal Energy Regulatory Commission in mid-October.
CAISO's board of governors on Monday agreed to extend and expand the ongoing efforts to mitigate against power interruptions this winter. The grid operator's board essentially endorsed the approach created by a collaboration of staff members at the California Energy Commission, California Public Utilities Commission, Los Angeles Department of Water and Power and CAISO last summer.
Released last August, the draft winter reliability plan was outlined to respond to the continuing natural gas storage limitations in the state (see Daily GPI, Aug. 23). The plan assumes that "normal winter demand" can be met by the three other storage facilities in the region.
The summer effort addressed operational and market issues on the electric system that have arisen in the wake of the limited availability of Southern California Gas Co.'s 3,600-acre Aliso Canyon underground storage facility (see Daily GPI, May 19). Current measures are set to expire on Nov. 30, and CAISO will be filing to extend these provisions for another year (through November 2017).
California's major energy agencies' collaboration addressed the challenges of serving normal winter average demand without using Aliso Canyon, concluding that can be done by increasing withdrawals from other natural gas fields, among other steps. "For the coldest days, while risk exists, demand can be met by withdrawals from other fields and replacement of lost generation from other resources," the draft plan noted.
In addition to keeping the summer mitigation measures in place (see Daily GPI, May 23), the winter plan would add elements for various gas operations, such as:
- More gas conservation measures;
- Extending noncore balancing rules for the largest gas users;
- Adding balancing rules for core (mostly residential) customers;
- Setting maximum gas consumption levels for electric generators;
- Requiring reports on pipeline service restoration;
- Preparing to buy additional gas supplies; and
- Preparing to buy liquefied natural gas supplies.
The assessment concluded that for the gas system to maintain reliability under current conditions without Aliso Canyon, supportable gas demand is estimated at 4.7 Bcf/d, compared with the 5.2 Bcf/d demand forecast established by the one-in-10 cold day design standard.