Four Big Unanswered Blackout Questions

Four Big Unanswered Blackout Questions

Photo by Sam Hodgson

Buildings with little or no light loomed large and eerily over the city during the blackout that left 1.4 million SDG&E customers powerless.

 

Now that power has been restored to 1.4 million San Diego Gas & Electric customers, state and federal regulators are focused on figuring out who’s responsible for San Diego’s massive blackout and what measures, if any, could have prevented it.

SDG&E says a cascading series of failures caused the collapse of the region’s power grid Thursday afternoon. The utility says it was started by a single repair job gone wrong more than a hundred miles away in Arizona. Here’s a rundown of four major questions that haven’t been fully answered:

What exactly went wrong?

SDG&E, the region’s major electricity provider, blames an outage near Yuma, Ariz., for starting the unprecedented collapse of its system. It says that outage stopped power from coming into the county, knocked out the San Onofre nuclear power plant and shut down the entire system.

Arizona Public Service, the utility that operates the power station where the outage happened, has released few details so far. It said an employee was trying to make repairs, a short circuit occurred and the safeguards that typically prevent an outage from spreading didn’t work.

“It should not have impacted a single customer and we want to know why that didn’t happen,” APS spokesman Damon Gross said.

The uncontained surge from the outage cut all power from a high-voltage transmission line connecting Arizona and California, and initiated a chain of events that also cut off the San Onofre plant, which was serving as San Diego’s other main source Thursday.

All together, that turned off the lights for millions of people for 12 hours.

Why did the San Onofre plant shut down?

On Thursday, San Onofre was San Diego’s main source of electricity. Before the blackout, SDG&E says its customers were using about 4,300 megawatts of power. About 2,200 megawatts came from San Onofre, more than 1,500 megawatts came from the Arizona power line and the rest came from local plants. (One megawatt can power several hundred homes.)

Losing the power line connecting us to Arizona placed more pressure on San Diego in two ways. First, the grid instantly lost about a third of its power supply. Second, the customers normally served by the Arizona power line were transferred to nearby power grids, including San Diego’s, which are all interconnected.

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It’s unclear how the shift happened. Jim Avery, SDG&E’s senior vice president of power supply, said it occurred automatically when the Arizona power line went out. The California Independent System Operator, the agency ultimately responsible for operating the power grid, did not return messages seeking an explanation.

Utility watchdog Michael Shames doubts the shift occurred automatically. Shames, executive director of the Utility Consumers’ Action Network, said San Diego’s grid is operated in real-time by the Independent System Operator and SDG&E. A shift of that magnitude would not have happened without both agencies being involved, he said. Somebody made the decision to accept more customers, he said, but it’s still unknown who.

Whether the shift happened automatically or by choice, Avery said it was crucial step in the downfall of San Diego’s systems. Adding more customers immediately boosted the amount of power being demanded from San Onofre and overwhelmed the power plant’s capabilities.

San Onofre then turned off for the same reason the breaker in your home turns off power when you plug too many appliances into an outlet, Avery said. Before a surge in power damaged San Onofre’s equipment, computer sensors turned off the plant, he said. (And turning the power back on takes a lot longer.)

However, the company that operates San Onofre hasn’t gone that far. Steve Conroy, spokesman for Southern California Edison, said the plant was operating at full capacity before the Arizona power line was cut and the company is still investigating why the plant turned off.

How could San Diego’s entire power grid have collapsed from one short circuit?

Shames said the amount of power available from local power plants is designed to support San Diego’s grid, even during peak hours in sweltering heat (like Thursday’s). And when the region has lost power from San Onofre in the past, SDG&E said it has still managed to keep most of the lights on or brownout only some areas.

But Avery said SDG&E never anticipated what happened Thursday. The company planned how to maintain power without San Onofre and the Arizona power line, but never for maintaining power in those conditions while also handling more customers from Arizona. (It isn’t clear how many additional customers were transferred. SDG&E referred follow-up questions to the Independent System Operator, which didn’t return messages.)

“We planned for what we deem to be a credible threat. We do not plan for every contingency,” Avery said. “What occurred is greater than we planned for.”

Because SDG&E never planned for it, Avery said, the safeguards to prevent a system-wide collapse didn’t work. San Diego has three substations where grid managers and utility officials can stop a surge from turning off local power plants, too. They closed none before the blackout. If they had, the whole system wouldn’t have failed.

Avery said the new conditions arrived too fast for humans to act and the computer sensors that could have automatically closed the gateways didn’t because the scenario had never been planned for.

“The system did exactly as it was designed to do,” Avery repeated several times.

Murray Jennex, an associate professor at San Diego State who’s worked with utilities for 20 years, said computer sensors should have stopped the outage in Arizona from spreading to San Diego’s system.

Shames said if the Independent System Operator transferred the Arizona customers to San Diego without a plan approved by state oversight officials, it would have been illegal.

“Heads are going to roll at [the Independent System Operator] if that’s true,” Shames said. “What SDG&E is telling you doesn’t add up.”

So who’s ultimately responsible for the blackout?

That’s the question several state and federal regulators have set out to answer in the coming weeks. The California Independent System Operator ultimately operates the state’s power grid, including San Diego, and has promised to participate with those investigations and release more information about why the blackout happened when it becomes available.

The Federal Energy Regulatory Commission and North American Electric Reliability Corp. have begun a joint inquiry. So has the Western Electric Coordinating Council, the regional group that manages the western power grid.

If you have any insight to share about who’s responsible, please contact me by email or leave a comment below.

Keegan Kyle is a news reporter for voiceofsandiego.org. He writes about public safety and handles the Fact Check Blog. What should he write about next?

Please contact him directly at keegan.kyle@voiceofsandiego.org or 619.550.5668. You can also find him on Twitter (@keegankyle) and Facebook.

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48 comments
Anna Doxie
Anna Doxie subscriber

If is not SDGE then who is? My claim is large and needs to compensated! Why isnt Sdge giving the who so we can pursue.

asdoxie
asdoxie

If is not SDGE then who is? My claim is large and needs to compensated! Why isnt Sdge giving the who so we can pursue.

Don Wood
Don Wood subscriber

I believe that the San Onofre Nuclear powerplant never shut down. Instead, the transmission line connecting it to San Diego tripped off. One question is how many of the local major powerplants were operating and putting power into the grid on August 18 before the blackout? If they weren't operating on the hottest day of the year, why not?

Don Wood
Don Wood

I believe that the San Onofre Nuclear powerplant never shut down. Instead, the transmission line connecting it to San Diego tripped off. One question is how many of the local major powerplants were operating and putting power into the grid on August 18 before the blackout? If they weren't operating on the hottest day of the year, why not?

joe vargo
joe vargo subscriber

When Sheriff Gore can spend 2 hours explaining away a murder. It's about power. No pun intended. Buy yourselves a really nice, shiny new flash light.

joev
joev

When Sheriff Gore can spend 2 hours explaining away a murder. It's about power. No pun intended. Buy yourselves a really nice, shiny new flash light.

Karen Shaffer
Karen Shaffer subscriber

Yep, I think we need to expect accountability before we can get it. Let's not just forget about it.

KMH
KMH

Yep, I think we need to expect accountability before we can get it. Let's not just forget about it.

susanf
susanf subscribermember

where is the mayor? the city council? the board of supes? we the people need some answers.

susanf
susanf

where is the mayor? the city council? the board of supes? we the people need some answers.

Richard Ross
Richard Ross subscribermember

I just have one request from VOSD...please don't refer one to half a dozen other web publishers that require one to log in...to many passwords...enough is enough.

Activist
Activist

I just have one request from VOSD...please don't refer one to half a dozen other web publishers that require one to log in...to many passwords...enough is enough.

Nickolas Furr
Nickolas Furr subscriber

Outstanding. I understand now. Thank you for responding. And I'm glad to see so many people chiming in with questions of their own.

Nickolas
Nickolas

Outstanding. I understand now. Thank you for responding. And I'm glad to see so many people chiming in with questions of their own.

Susan Brinchman
Susan Brinchman subscriber

Make no mistake, this is a serious failure of the newly developing smart grid—experts have heavily criticized its insecurities. Our national security is being risked with the interconnectivity of the grid, which easily fails like a stack of dominoes, with one event. Conducting a search on smart grid and security issues will readily bring up information about these criticisms that have been swept under the rug by bureaucrats and utilities alike.

ConcernedCitizen
ConcernedCitizen

Make no mistake, this is a serious failure of the newly developing smart grid—experts have heavily criticized its insecurities. Our national security is being risked with the interconnectivity of the grid, which easily fails like a stack of dominoes, with one event. Conducting a search on smart grid and security issues will readily bring up information about these criticisms that have been swept under the rug by bureaucrats and utilities alike.

Dagny Salas
Dagny Salas memberadministrator

Dagny Salas, web editor

John Keasler
John Keasler subscriber

Is anyone addressing the issue of so many gas stations being unable to stay open because they did not have backup generators? This could have been tragic if an evacuation had been ordered. I have yet to hear this addressed anywhere in the press.

Art Nut
Art Nut

Is anyone addressing the issue of so many gas stations being unable to stay open because they did not have backup generators? This could have been tragic if an evacuation had been ordered. I have yet to hear this addressed anywhere in the press.

Nickolas Furr
Nickolas Furr subscriber

Is it true that you've been deleting comments here that refer to this story? If that's true, then I'm disappointed. I always thought you were better than the Union-Tribune. I could be wrong.

Nickolas
Nickolas

Is it true that you've been deleting comments here that refer to this story? If that's true, then I'm disappointed. I always thought you were better than the Union-Tribune. I could be wrong.

Richard Ross
Richard Ross subscribermember

Accountability doesn't exist in the upper level of SDG&E as exhibited by their president. His T.V. remarks displayed a posture of reaction to events rather that being proactive with analysis and preventive measures.

Activist
Activist

Accountability doesn't exist in the upper level of SDG&E as exhibited by their president. His T.V. remarks displayed a posture of reaction to events rather that being proactive with analysis and preventive measures.

Richard Ross
Richard Ross subscribermember

After watching the broadcast by the president of SDG&E one could only recall that old adage as it applies here. That it wasn't only the workman in Arizona that promoted to the level of incompetence.

Activist
Activist

After watching the broadcast by the president of SDG&E one could only recall that old adage as it applies here. That it wasn't only the workman in Arizona that promoted to the level of incompetence.

Stephen Prosapio
Stephen Prosapio subscriber

San Diego is the best place in the world to live. Evidenced by the fact that when threatened with (as the rumor went) no power for at least 24 hours, we hung out with neighbors and banded together. Other places in this country would NOT react the same way. This needs to be studied with a jaundiced eye. Not only do the guilty need to pay...new people need to come in and take action to ensure this can't happen here or elsewhere!

Oceanside Steve
Oceanside Steve

San Diego is the best place in the world to live. Evidenced by the fact that when threatened with (as the rumor went) no power for at least 24 hours, we hung out with neighbors and banded together. Other places in this country would NOT react the same way. This needs to be studied with a jaundiced eye. Not only do the guilty need to pay...new people need to come in and take action to ensure this can't happen here or elsewhere!

Bob Gardner
Bob Gardner subscriber

Sounds to me like government is dropping the ball while SDG&E exceeded everyone's expectations in getting the power back on.

rgardne70
rgardne70

Sounds to me like government is dropping the ball while SDG&E exceeded everyone's expectations in getting the power back on.

Kelly Donivan
Kelly Donivan subscriber

Regardless of the reason...my husband and I used the situation to really "test" our own emergency plans and resources. We learned a lot from this experience and know what we as a family need to do to improve and prepare better for a future and possibly more dire situation. I think everyone should do the same. Our little neighborhood pulled together and made the best of the situation.

Genxer65
Genxer65

Regardless of the reason...my husband and I used the situation to really "test" our own emergency plans and resources. We learned a lot from this experience and know what we as a family need to do to improve and prepare better for a future and possibly more dire situation. I think everyone should do the same. Our little neighborhood pulled together and made the best of the situation.

Bob Jones
Bob Jones subscriber

We all know this could happen again. The lack of factual information is a major concern to us all and hampers the self-help planning of all citizens.

rwj5125
rwj5125

We all know this could happen again. The lack of factual information is a major concern to us all and hampers the self-help planning of all citizens.

Phyllis Mirsky
Phyllis Mirsky subscribermember

The clearest explanation I've seen yet. Thank you, Keegan.

Phyllis
Phyllis

The clearest explanation I've seen yet. Thank you, Keegan.

Lee Hazer
Lee Hazer subscriber

I hope people who know what happened DO contact this reporter.

Leecal
Leecal

I hope people who know what happened DO contact this reporter.

Lee Hazer
Lee Hazer subscriber

And the govt. agencies (Police, Traffic, ) kept order. It wasn't perfect but it was order.

Leecal
Leecal

And the govt. agencies (Police, Traffic, ) kept order. It wasn't perfect but it was order.

Lee Hazer
Lee Hazer subscriber

the political arena ( meaning unlimited lobbyists making payoffs).

Leecal
Leecal

the political arena ( meaning unlimited lobbyists making payoffs).

Jeff Toister
Jeff Toister subscriber

Much of the reporting on this story here and elsewhere shifted on Friday to "Who is at fault?" Being so eager to fix the blame makes it very likely that those to blame will be on the defensive and less than forthcoming. Your first three questions were much more on target and I hope VOSD continues asking these questions. A scapegoat will emerge if there truly is one, but I would hope blame isn't the focus of reporting on the blackout. Ultimately, we want to know how and why it happened and have some peace of mind that it is unlikely to happen again.

Jeff T
Jeff T

Much of the reporting on this story here and elsewhere shifted on Friday to "Who is at fault?" Being so eager to fix the blame makes it very likely that those to blame will be on the defensive and less than forthcoming. Your first three questions were much more on target and I hope VOSD continues asking these questions. A scapegoat will emerge if there truly is one, but I would hope blame isn't the focus of reporting on the blackout. Ultimately, we want to know how and why it happened and have some peace of mind that it is unlikely to happen again.