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Power Line Bottleneck
Outdated network along I-5 clogs north-south energy flow
Carl T. Hall, Chronicle Science Writer Tuesday, January 30, 2001 ©2001 San Francisco Chronicle
One reason for Northern California's energy mess can be glimpsed out your car window along a busy stretch of Interstate 5.
An 84-mile system of power lines and substations, collectively known as "Path 15," runs near the highway from Los Banos to a Pacific Gas & Electric Co.
substation northwest of Bakersfield.
It's a critical link in California's power grid, the main electron freeway linking Northern California to Southern California, ultimately linking the region into a vast interstate network known as the Pacific AC Intertie.
Lately, though, the West Coast power grid has been tied in knots. And Path 15 has begun to resemble not so much a freeway as a dangerously clogged country lane -- one of the more visible snags in California's fractured power- transmission system.
"Path 15 is the biggest (congestion) problem we have right now," said Armando Perez, director of grid planning at the California Independent System Operator, created to oversee power supplies as part of the state's botched experiment in utility deregulation.
Unfortunately, there's no simple -- or cheap -- solution in sight.
Expanding capacity would cost an estimated $200 million to $300 million and take five to seven years to complete. That would include environmental reviews and land acquisition for an entirely new right of way, considered necessary to ensure the system's reliability and guard against cascading blackouts.
Path 15 includes two parallel main lines rated at 500-kilovolts each. The system connects at both its north and south ends to three 500-kilovolt lines. "That causes the same kind of bottlenecks you'd see when you go from three lanes to two lanes on a freeway at rush hour," Perez said.
Regional power authorities insist that fixing the bottleneck is far more complicated than just stringing up another bunch of wires along I-5. They also admit that nobody seems to be anxious to take the lead in solving the problem.
"It's a screwed up mess," said Jim McCluskey, transmission program specialist at the California Energy Commission. "The solution ultimately is some kind of grid expansion, but the problem is finding a way to fund that expansion."
Experts view the system as a relic of simpler times, when utilities could pretty much serve their own customers with locally generated power, calling on more distant resources only during rare emergencies.
Now, with blackout alerts a weekly routine, it seems the architects of California's foray into deregulation failed to take into account how the archaic energy- transport infrastructure would fit into the new era.
"The grid wasn't designed for the purposes it's being used for now," said Kevin Dasso, PG&E's director of electric transmission and distribution engineering.
Besides the seemingly obvious solution -- adding a third high-voltage line and substations -- PG&E is also looking into the possibility of stopgap measures to upgrade the system. These would involve certain engineering tricks to squeeze out a little more capacity at key junctures -- the equivalent of adding electronic toll-collection and car-pool lanes on the Bay Bridge.
But it's unclear whether that would make a real difference. Even the stopgap measures would take two to three years to implement and cost $100 million or more, Dasso said. Right now, nobody knows if PG&E will have the financial wherewithal to avoid Chapter 11 bankruptcy, let alone undertake a major capital project.
So that leaves Northern Californians with the prospect of ongoing power disruptions even when surplus energy is available on the southern side of the Path 15 bottleneck.
During the recent rolling blackouts, for example, generators in the Southwest were said to be producing plenty of power to have kept Northern California plugged in when the shortages arose. That's the main reason utilities managed to avoid rolling outages in Southern California, even though some "interruptible" customers have had their lights shut off throughout the state.
The wholesale power market also has been reflecting the impact of congestion along Path 15. Electricity prices have been significantly higher north of the bottleneck simply because that's where the mismatch between demand and supply has been most severe. During the month of December, for example, the average day-ahead wholesale price in the north was $308.74 per megawatt hour, compared with $223.07 to the south.
This summer, assuming California's energy woes persist as expected, the situation could tilt the other way, once the air conditioners crank up in Southern California and surplus power once again becomes available in the north.
A preliminary study, under way now at the Independent System Operator, is expected to conclude next month that a full-scale Path 15 expansion would be a good idea.
"From where I sit, it seems like a slam dunk," Perez said.
All agree that the congestion problems along Path 15 are a problem that somebody needs to solve -- and soon -- for the deregulated system to work. If it gets bad enough, regional power officials said, the result could be much bigger trouble than anyone now imagines.
"If a transfer path is carrying more power than it's capable of carrying, the sudden outage of that path could lead to cascading outages throughout the system," said Robert Dintelman, assistant executive director of the Western Systems Coordinating Council, which oversees the reliability of the power grid in 14 Western states.
Discussions have strung out over more than 10 years, participants acknowledge, fueled largely by municipal utilities anxious for better access to power from the Southeast. That gave little urgency to the problem as far as the big utilities like PG&E were concerned.
Grid upgrades are much further along outside California -- 2,604 miles of new transmission lines are planned in the Western region through 2009, but of that, fewer than 145 miles are planned in California.
The problem is no longer a lack of urgency but rather a lack of clear responsibility and financing.
Federal energy authorities see the problem and suggest that a new regional authority -- without links to any particular utility or power-generation interest -- might be set up in order to cut through the tangle.
Another possibility might be for the state to step in with a bond issue to finance construction, though that raises another big set of complicated financing issues.
-------------------------------------------------------------------------------- Transmission Bottleneck
PG&E's Path 15 is the main transmission route for power moving into Northern California, connecting PG&E's service area to power generators in Southern California and adjoining states. But while other key parts of the system consist of three main power lines, Path 15 has only two - causing the electron equivalent of a traffic jam during the current energy crisis. Source: California Independent Operator Chronicle Graphic
E-mail Carl T. Hall at email@example.com.
-- Martin Thompson (firstname.lastname@example.org), January 30, 2001