Big Island Customers Heed Request to Limit Use of Electricity, Preventing Need For Rolling Outages

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So far, so good. That’s the word from Hawaiian Electric as it continues to ask Big Island electricity customers to reduce their electricity use, especially in the early evening hours.

The initial request was made Monday, Aug. 29, for customers to conserve power from 5-9 p.m. each day this week. The utility company renewed its request Tuesday, Aug. 30. Hawaiian Electric has also asked its larger commercial customers, including government, hotels and retailers, to voluntarily reduce electricity use this week.

The Big Island has since stepped up to roll back its electricity consumption.

“Customer conservation efforts helped ensure sufficient power was available to meet the early evening peak demand and prevented the need for rolling outages,” Kristen Okinaka, Hawaiian Electric spokesperson, told Big Island Now in an email Wednesday morning.

The utility continues to request customers take measures to conserve electricity through the end of this week, no matter how small.

“Small actions do make a difference,” Okinaka said.


Suggested conservation steps include turning off or reducing use of lights and air conditioners; delaying showers, laundry and dishwashing activities; and going out for dinner or minimizing cooking until later in the evening.

The conservation request comes as the Hāmākua Energy LLC plant in Honoka‘a was unexpectedly shutdown because of the unavailability of ammonia it uses for pollution control.

Scott Valentino, president of Pacific Current, the parent company and owner of Hāmākua Energy, said in an email to Big Island Now on Tuesday that the ammonia is necessary for the Honoka‘a facility’s emissions control system. It is used to decompose nitrous oxides in the exhaust gas into nitrogen and water vapor to meet emissions limits in the company’s stationary source air permit. The permit is issued by the state and the plant must be in compliance with federal Environmental Protection Agency regulations.

“Due to supply chain issues, Hāmākua Energy LLC is experiencing a delay in the delivery of necessary product to operate within the (nitrous oxide) emission limits in accordance with the plant’s air permit,” a statement from Hāmākua Energy emailed to Big Island Now on Tuesday said. “We are continuing to pursue other supply sources and intend to have the product delivered to Hawai’i Island and transported to the plant in the next several days. Hawaiian Electric has been notified of the details of the situation and (has) been supporting us in sourcing the necessary product as best they can so that it can ensure the reliability of the Hawai’i Island grid.”

The plant, in total, normally produces about 60 megawatts of electricity for the Hawaiian Electric grid, with about two-thirds coming from two combustion turbines and the remainder from a steam turbine, if they are all running at full capacity, according to Valentino.


Not only is Hāmākua Energy offline, Hawaiian Electric’s Hill Plant Nov. 5 is undergoing annual maintenance and is out of service. The unit supplies 14 megawatts of power to the utility company’s grid when it is operational.

“We’ve accelerated repair and maintenance of our smaller units,” Okinaka said in her Wednesday email. “Hill Plant Unit No. 5 is expected to return from annual maintenance outage in September.”

The utility company’s 15-megawatt Puna Steam Plant is also offline for extensive mechanical repairs. Hawaiian Electric also won’t have the benefit of wind energy.

Hawaiian Electric does purchase wind energy from two producers on the island, Hawi Renewable Development and Pakini Nui Wind Farm. Hawi can provide up to 10.5 megawatts and Pakini Nui up to 20.5 megawatts, but the amount they can provide to the grid depends on the strength and duration of the wind.

Wind resources are forecast to be lower than normal this week.


So that’s a total of nearly 90 megawatts of power unavailable to the Hawaiian Electric grid right now. Okinaka explained that the evening peak of electricity use on the Big Island varies, but averages at about 175 megawatts.

“Generation capacity is very close to that, so we’re asking customers to conserve,” she said. “The hours from 5-9 p.m. are considered the evening peak, when customers use the most electricity. Conservation is necessary to help ensure sufficient power is available to meet that demand.”

Besides asking Big Island customers across the board to limit their electricity use during the evenings, Hawaiian Electric is also running units longer and on different schedules than usual to ensure the availability of sufficient power generation and requested maximum output available from Puna Geothermal Venture, which provides about 26 megawatts to the grid.

It’s all in an effort to keep the supply of power available to customers in balance with the demand for power. If that balance shifts the wrong direction, additional measures might be necessary.

“When customer demand is greater than the supply, it can create significant instability on the grid and cause additional generators to trip offline and result in a more widespread, possibly islandwide, outage,” Okinaka said.

Manual load shedding, or rolling outages, is a protective measure that prevents against even greater, longer-term losses of power.

“If necessary, rolling outages would be initiated in various areas around the island,” Okinaka said, adding the impacted areas and the timing of the outages, if necessary, would be based on the amount of electric demand that needs to be reduced at the time.

As long as Big Island customers continue to heed the conservation request, however, those measures will not be needed. If, however, outages are necessary, Hawaiian Electric will notify customers in advance via social media.

“Conservation efforts by residential and business customers prevented the need for rolling outages on Hawai‘i Island Monday and Tuesday nights,” a press release from Hawaiian Electric on Wednesday afternoon said.

The last time rolling outages were necessary was in 2016.

“We’re all in this together,” Okinaka said in a press release Tuesday. “The best way to avoid the inconvenience of a brief outage is to minimize the use of appliances, especially air conditioning and anything that generates heat. Consider shutting off your water heater for a few hours — the water will still be hot later. Every bit you conserve is a big help.”

Hawaiian Electric again renewed its conservation request in its Wednesday afternoon press release. Okinaka said in her email that the utility company will notify customers if the request needs to be extended longer than this week.

Customers can follow @HIElectricLight on Twitter for updates.

An update from Hawaiian Electric is planned during the next Waimea Community Association online town hall meeting scheduled for Thursday, Sept. 1. A status report about several alternative energy projects and initiatives on the island also is on the agenda.

The meeting begins at 5:30 p.m. and will be streamed live on the association’s Facebook page and can also be viewed via YouTube by visiting the association’s website for the link.

Nathan Christophel
Nathan Christophel is a full-time reporter with Pacific Media Group. He has more than 25 years of experience in journalism as a reporter, copy editor and page designer. He previously worked at the Hawaii Tribune-Herald in Hilo. Nathan can be reached at
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