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The Honolulu Advertiser
Posted on: Thursday, April 5, 2007

Quake outage won't recur, HECO says

 • PDF: Executive summary of Power Engineers report on the Oct. 15 outage

By Rick Daysog
Advertiser Staff Writer

Switches at HECO's Kahe Point plant automatically shut down the generators when the earthquakes generated false readings.

HECO

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WHAT WENT WRONG, HOW IT'S BEEN FIXED

Here are some of the problems and solutions arising from the Oct. 15 power outage:

Problem 1: When the earthquakes hit, mercury switches on two of Hawaiian Electric Co.'s largest generators gave false readings that the generators were in danger because of low fluid, which triggered an automatic shutdown. The shutdown caused a cascading effect that eventually left the entire island of O'ahu without power.

Status: The company disabled the automatic shutdown mechanism so that the generators now have to be shut down manually.

Plant operators have been given refresher training on the actions to take should low-fluid-level alarms activate.

Problem 2: Shaking from the earthquakes at Kahe and Downtown Honolulu power plants prompted plant employees to manually trip the smaller generators at those plants after they mistakenly believed that shaking was caused by the machines themselves and that the generators were at risk of permanent damage.

Status: While the manual trips were proper given the amount of information available at the time, the company has provided additional training for plant operating staff for similar situations.

Problem 3: After power had been cut off to all 291,000 HECO customers, HECO initially planned to restart, or "blackstart," generators at Kahe and Waiau within three hours of the outage. But due to the complexity of the process and equipment problems, HECO's efforts to restart those generators were delayed by an hour and a half.

Status: HECO is working with power plant manufacturer Siemens Westinghouse for additional training for its employees on blackstarting the system.

The company also is seeking approval for a new $130 million power plant at Campbell Industrial Park, which would have blackstarting capabilities in cases of outages. The 110-megawatt plant is scheduled to be built by 2009 but requires approval by the state Public Utilities Commission.

Source: Power Engineers, HECO

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If an earthquake — similar to the twin temblors that shook the Islands six months ago — were to occur again, O'ahu wouldn't suffer a 15-hour power outage as it did Oct. 15, Hawaiian Electric Co. said.

The problems behind the outage have been fixed, the company said.

"The bottom line is that we've taken immediate steps to address the underlying effects of the Oct. 15 earthquake," said Lynne Unemori, HECO spokeswoman. "We've done the short-term fixes. We're still looking at the long-term solutions for additional protection."

That's good news for 291,000 HECO customers who were without electricity for most of the day on Oct. 15. The quake initially tripped off three HECO generators, or roughly 25 percent of the utility's peak capacity, which set off a chain of events that led to the automatic shutdown of electricity islandwide.

To make sure it doesn't happen again, HECO has implemented a number of technical fixes to its generators, such as disabling an automatic shutdown mechanism that helped trigger the outage.

It also has provided additional training for staffers for earthquake scenarios and has initiated studies on how to better restore electricity to customers and quicken the restart process of the company's generators once they go offline.

NEW PLANT PLANNED

The long-term solutions will be more costly. Even before the quake, the company was seeking regulatory approval for a $130 million, 110-megawatt power plant at Campbell Industrial Park, which will not only increase HECO's generating capacity on O'ahu but will include special machinery to restart or "blackstart" generators at the new plant.

State Consumer Advocate Catherine Awakuni believes that HECO has been thorough in addressing some of the immediate problems arising from the outage. But Awakuni said her office is still conducting its own investigation into the causes and has hired a consultant, Kansas-based Sega Inc., to examine some bigger-pictures issues surrounding the outage.

"I think they've taken the steps to address some of the immediate problems their consultants have identified," Awakuni said. "Whether there are additional issues that need to be addressed is another matter."

Many of HECO's adjustments were in response to recommendations by Power Engineers Inc., an Idaho-based consulting firm hired by the local utility.

RESPONSIBLE STEPS

In a 90-page report in December, Power found that the outage was directly caused by the earthquakes and that HECO employees acted in a responsible way in attempting to keep the system going and in restoring electricity once the system crashed.

But Power also noted that safety mechanisms attached to the company's two largest generators — an automatic lockout mechanism and fluid-level, mercury switches — played a major role in the blackout.

According to Power, 20- to 30-year-old, manufacturer-installed switches in HECO's largest generators — the 142-megawatt Kahe 5 and Kahe 6 units — gave false readings. The switches are designed to shut down a generator automatically when fluid is dangerously low and prevent damage to the generator. On Oct. 15, the shaking of the earthquake caused the switches to indicate that fluid was low when, in fact, it was not.

If it wasn't for the automatic shutdown of those generators, "the HECO system would have survived," Power said in the report.

MECHANISM DISABLED

According to Unemori, HECO has now disabled the automatic shutdown mechanism. Now, any lockouts of the generators have to be done manually, she said.

Unemori noted that the company has not replaced the mercury switches, which continue to gauge fluid levels for the steam generators but are no longer connected to the automatic lockout device.

Should those fluid levels fall to levels that could damage the expensive machinery, it would set off alarms to alert plant operators.

Power suggested the switches be replaced with ones that are less likely to give a false reading.

When asked why the switches had not been replaced, Unemori said the task would require the shutdown of HECO's largest generators, which serve as the workhorse for the entire system. Typically, shutdowns of those units are planned months in advance, she said.

"The bottom line is that having those switches there today doesn't present the risk that they did on Oct. 15," she said.

"In wake of the outage, we've had many lessons learned and there have been many meetings at all levels of the company, from the executive level down to the detailed operations level," Unemori said.

According to Unemori, many of the long-term fixes that are being mulled by the company will require significant community and regulatory input.

GREATER CAPACITY

HECO recently announced plans for a new, $130 million power plant at Campbell Industrial Park. The 110-megawatt plant will not only significantly increase the local utility's generating capacity but also will include equipment designed to restart HECO's generating units once they go offline. The lengthy process of restarting generators was one reason power was out for more than 15 hours on Oct. 15.

The new Campbell Industrial Park power plant requires the approval of the state Public Utilities Commission and is not expected to be completed until 2009, even if that approval comes quickly.

Reach Rick Daysog at rdaysog@honoluluadvertiser.com.