By the OGJ Online Staff
HOUSTON, June 18 -- Instituting its early warning system for the first time, the California Independent System Operator Sunday warned rolling blackouts are possible Monday and Tuesday and called for maximum conservation efforts.
The ISO said the state's first heat wave of the season is producing temperatures nearly 10° higher than forecast and is expected to lead to higher demand for power, especially air conditioning. The grid operator said between noon and 8 p.m. Monday and Tuesday looks "especially tight."
It forecast peak demand of 36,492 Mw Monday and 38,810 Mw Tuesday. Statewide temperatures are expected to intensify Tuesday, stressing the system in the afternoon.
The ISO said Stage 3 emergency notice and notice of load interruptions will be issued when the load interruptions are imminent or have actually begun. The grid operator unveiled a plan Friday intended to give Californians 24 hr and 48 hr notice about the likelihood of rotating outages. The notification plan was developed in response to California Gov. Gray Davis's June 1 directive.
If rotating outages appear imminent, CEO Terry Winter said Friday, the ISO will give local utilities and the governor's office 90 min advance warning. During a news conference Friday, Winter said this will give utilities time to provide 1 hr notice to the news media, the public, and other agencies about where the outages will occur and how many customers will be affected.
Winter warned the new notification system is not foolproof. He noted temperature differences of as little as 3-4° can cause power demand to fluctuate 3,000-4,000 Mw. If rolling blackouts do not occur after a warning is issued, he said, it doesn't mean the ISO's forecast was wrong because conditions can change at the last minute.
He noted conservation could cause power demand to drop enough to avoid blackouts, temperatures could fall, or the ISO could receive imported power at the last minute.
Up to now, Winter said Friday, the state has been fortunate because some generation came back on line earlier than expected and the weather had been cooperative.
"But we are clearly not out of the woods," he said.