Hawaiian Electric Co. has restored power to some 57,000 customers affected by outages Thursday that occurred after an unexpected loss of the largest generating unit on Oahu — for a second day in a row.  

The same AES-owned generator that crashed on Wednesday came back online later that night crashed once again Thursday at about 11:22 a.m., prompting the latest outages. 

The loss of this generating unit forced HECO to shut off power to customers in various sections of the island including: Waialua, Kahuku, Waihee, Kaneohe, parts of Kailua, the Kapiolani area, downtown Honolulu, Waiakamilo, Moanalua, Halawa, Moanalua, and Waipahu, according to a HECO news release. 

Power was restored to nearly all circuits by approximately 12:30 p.m. Crews are still working to restore power in some areas, including parts of Kalihi and Kailua. 

On Wednesday, the independent AES plant unexpectedly went out of service at 11:23 a.m., touching off outages that lasted about 30 minutes. The AES plant was returned to service today at about 8 a.m. Thursday’s outages occurred after the AES plant unexpectedly went out of service again. 

The targeted emergency outages were necessary to avoid a more widespread outage or damage to the electric system from an imbalance of too much demand versus too little available generation, according to the release 

HECO spokesman Darren Pai said in the release: “We understand these outages are disruptive to our customers, so we thank them for their patience and understanding. We apologize and want our customers to know that we are working with AES to thoroughly investigate this issue and take whatever steps are necessary to ensure this source of generation will continue to provide reliable power,” said Darren Pai, Hawaiian Electric spokesperson.