2006 BIG ISLAND EARTHQUAKE: 1 YEAR LATER
Electric company makes switches
Hawaiian Electric makes various improvements in an attempt to prevent blackouts like 2006’s
LAST OF FIVE PARTS
On a rainy Sunday morning last October, a powerful earthquake off the Kohala Coast of the Big Island, followed by a powerful aftershock, shook up the state and triggered a cascading shutdown of Oahu generating units -- including Hawaiian Electric Co.'s two largest -- that left many on the island without power for nearly 19 hours.
Making things worse, congestion on public phone circuits hampered communication efforts for HECO, which found it difficult to get through with timely information to radio station KSSK, the primary emergency broadcast outlet.
Although HECO said it is impossible to guarantee there will never be a total power failure again, steps it has taken since the 6.7 and 6.0 jolts of Oct. 15, 2006, likely would prevent a similar islandwide outage today if the state were facing the exact situation as a year ago, according to HECO spokeswoman Lynne Unemori.
"The biggest step that we've taken is we've modified the two largest HECO generating units to prevent safety relays from falsely locking out during earthquake vibrations," Unemori said. "On Oct. 15 it was found that the lockout of these relays resulted in these generating units losing the ability to maintain power, so they eventually tripped offline."
HECO, which even before the earthquake had said it needed more capacity to meet energy demands of its now 293,000 customers, won approval in May from the state Public Utilities Commission to build a $142.3 million, 110-megawatt plant in Campbell Industrial Park that will run exclusively on renewable fuels made from biodiesel. Construction of the plant is expected to begin next spring with completion scheduled for mid-2009.
The upshot of the new plant is that it will be a combustion turbine with a faster start-up time compared with the steam-generating units at Kahe and Waiau.
"We're looking forward to having another option to restarting the system in the unlikely event of an islandwide outage," Unemori said.
In last year's islandwide outage, HECO simultaneously started units at its Kahe and Waiau plants with the plan of using whichever generator came online first -- it was Waiau -- to begin energizing the rest of the electric system.
Once the first generator was brought online, demand for power was added to create a balance between supply and demand so the system did not destabilize and shut down again. The slow buildup left half of Oahu's customers without power for more than 14 hours, with the process taking nearly 19 hours to restore power for all but 2,200 customers.
Unemori said HECO is now evaluating whether a larger block of customers could get power restored once a significant portion of the electric grid is energized.
HECO is also studying a fourth option for receiving power in which the company would use the generating unit at one of Campbell Industrial Park's independent power producers, Kalaeloa Partners, which has a combustion turbine like the one that HECO will install at its new plant.
HECO said it has installed a dedicated phone line from its emergency operations center to KSSK to increase the utility's ability to communicate with the radio station early and regularly to share information during a major emergency.
HECO also now has two different phone-service providers for the center in case one loses service.
In addition, HECO installed new outage-management software this year that allows for computer-simulated training of personnel at its dispatch center for various emergency scenarios.
Maui Electric Co., which had an islandwide power failure for about 7 1/2 hours when vibration sensors tripped generators at its Maalaea plant, has determined it does not need to do anything different with its units. However, MECO has bolstered its backup emergency communications abilities by increasing backup power sources for its internal phone and computer systems so that they will stay up during an outage, as well as increasing its inventory of mobile radios and satellite phones.
Unlike Oahu and Maui, the Big Island did not lose all of its power, and Hawaii Electric Light Co. was able to restore power to 98 percent of its customers about 5 1/2 hours after the earthquakes tripped relays at HELCO's transmission substations. Unemori said HELCO might remove or replace some of the relays to prevent a similar occurrence. She also said HELCO has made improvements to its text messaging and paging system.