Hawaiian Electric Industries Inc. is suing the operator of Hawaiʻi’s only petroleum refinery, alleging that substandard fuel produced by Par Hawaiʻi Refining LLC caused millions of dollars in damage to power plants on the Big Island and Kauaʻi last year.

The lawsuit alleges tainted naphtha fuel caused “catastrophic damage” to a 60-megawatt power plant in Hāmākua that produces 25% to 30% of the electricity for the Big Island.

Naphtha is a gasoline-like byproduct of refining petroleum at Par Hawaiʻi’s Kapolei refinery. The fuel was delivered to Hāmākua by IES Downstream LLC, which was also named as a defendant in the lawsuit.

The lawsuit alleges Par produced naphtha that contained three times the amount of alkali metals such as sodium, potassium and lithium that is allowed under the power plant’s fuel purchasing agreement.

The faulty fuel caused extreme corrosion that ruined two gas turbines at the plant, according to the lawsuit.

Par Hawaiʻi did not respond to a request for comment Monday, and IES was unavailable for comment. Randall Whattoff, one of the lawyers who filed the lawsuit on behalf of HEI and former Hāmākua plant owner Pacific Current LLC, declined to comment on the case.

The Hāmākua plant was owned by Pacific Current LLC, a subsidiary of HEI, and had an agreement to produce and sell electricity to Hawaiʻi Electric Light Company for the Big Island grid.

The lawsuit alleges the faulty fuel was delivered to the Hāmākua plant sometime after July 2023, and workers at the plant noticed in December the turbines were not running properly. The allegedly tainted fuel was “effectively eating away at the turbines,” according to the suit.

The corrosion was discovered in February and March of 2024, and the Hāmākua plant was unable to produce power from late February until early June of last year. The plant operator was finally able to resume operations with a new turbine it purchased for $8.27 million, according to the filing.

The lawsuit lists another $1.7 million in costs associated with replacing the second turbine and lost electricity sales as well as another $4.4 million in lost capacity payments from Hawai’i Electric Light Co.

The Kauaʻi Island Utility Cooperative also uses naphtha for fuel and detected similar corrosion in its turbine, but the lawsuit does not detail that damage or costs.

The Hāmākua plant was sold earlier this year to Harbert Management Corp.

The suit alleges breach of contract and negligence. Read it below: