California back on blackout watch; BPA also on alert

HOUSTON, Feb. 13�With 10,000 Mw out of service, electricity reserves are "dangerously low" raising the possibility of rotating blackouts during Tuesday's peak evening demand, the California grid operator said.

During a 4 p.m. PST briefing Tuesday, Patrick Dorinson, spokesman for the California Independent System Operator (ISO), said the situation "appears to be looking better. But with these margins, anything could happen."

Now in its 29th day of the highest emergency alert, the ISO has not had to interrupt firms customers since mid-January. To avoid rotating outages, Dorinson said the ISO called on Pacific Gas & Electric Co., a unit of PG&E Corp., to ask for volunteers from its interruptible load program to turn off power at 6 p.m. PST.

But Dorinson noted the program has ended and customers who participated are no longer required to go off line. Likewise, he said, the ISO might ask Southern California Edison to call for voluntary interruptions.

Because of a cold spell, demand spiked up 1,300 Mw Tuesday morning over the previous day, just at a time the grid operator lost an additional 2,000 Mw of generation. Dorinson said the plants were down because of mechanical problems.

He said the ISO has been able to obtain 3,000 Mw from the Northwest. However, Tuesday the Bonneville Power Administration said generation on the Columbia River is being increased through the end of the week to avoid power shortages in the Northwest during the current cold weather.

Greg Delwiche, BPA vice president for power supply, said spring runoff into the Columbia River is now forecast to be the fourth lowest in over 70 years. Hydro generation this winter has been 4,000 Mw less than the past 5-year average. Meanwhile, power normally available from California has dried up due to shortages there.