Hawaiian Electric is considering whether to delay the retirement of its fossil-fuel-dependent Kahului power plant as it scrambles to secure spare parts for four engines at another key facility.
Earlier this month, the company received the “unexpected news” that the supplier of spare parts for four units of the Maalaea Power Plant may not be able to supply them, Hawaiian Electric told the state Utilities Commission in a letter Monday.
The four large diesel engines at Maui County’s largest power plant provide up to 50 megawatts of the island’s total firm generating capacity of 248 MW, according to Hawaiian Electric spokeswoman Shayna Decker.
“As we continue to explore ways to expand the operation of the four units and work to bring in more renewable energy resources, at the same time it is prudent for us to assess whether postponing the retirement of the units generation from the Kahului Power Plant is required,” Decker said in an email Thursday. “We are reviewing all options to ensure that we continue to have an adequate supply of electricity to meet the energy needs of our Maui customers.”
Hawaiian Electric has planned to retire the Kahului plant in 2024 as the state moves towards its goal of 100% renewable energy by 2045. The plant was closed in 2014 but reactivated in 2016 to meet a growing demand for electricity after the closure of Hawaiian Commercial & Sugar Co., which once supplied power to island residents.
In December, the PUC approved plans by Hawaiian Electric to make equipment changes to two of four retired oil-fired generator sets at the Kahului Power Plant, Decker said. Two units will be used to control the voltage and maintain the inertia of the system without using fuel oil, while the other two will be permanently shut down and will no longer be able to produce electricity.
Commissioned in 1948, the Kahului Generating Station generates 36 MW that will need to be replaced before being taken offline, making remaining facilities and future clean energy projects crucial to Hawaiian Electric’s plans.
Given the supply chain issues, Hawaiian Electric told the PUC it has contacted some suppliers and tried to acquire spare parts and materials ahead of schedule whenever it can.
In one case, Hawaiian Electric contacted Mitsubishi Heavy Industries Engine & Turbochargers, which supplies parts for all four Maalaea units. The Chicago office of the company’s US subsidiary informed Hawaiian Electric that “MHIET has not yet had a specific timeline until parts supply is complete.”
“We would certainly like to retain MECO’s parts supply for the engines as much as possible,” the company said in a March 2 letter. “However, the engines have been manufactured for over 40 years or so, some engine related parts may no longer be available due to closure of operations at our suppliers and if there is no other way to produce rooms.”
The response surprised Hawaiian Electric’s senior vice president, an operations manager, Jim Alberts, told the PUC in a letter Monday. He said “The fact that MHIET’s response was not an unequivocal commitment to continue supplying parts is of sufficient concern to warrant the company reviewing Maui’s capacity planning and power reserve margin.”
Hawaiian Electric has enough spare parts to “an additional major overhaul of 12,000 operating hours for each engine.” With overhauls planned over the next two years and ongoing operations showing it takes around 30 months to reach 12,000 hours of operation, the engines will be at or near the end of their life by 2025 or 2026, depending on the letter.
Hawaiian Electric is working to obtain enough replacement parts to extend the life of the units, but few such engines still exist and the critical parts needed are unique to the Mitsubishi version.
“However, the uncertain circumstances must be taken into account, and it is no longer safe to assume the continued operation of these units beyond the dates indicated above in capacity planning for Maui,” said Alberts. “As an example, it may not be prudent to remove Kahului units 1 to 4 before sufficient capacity is in service to replace the 36 MW they represent as well as the 50 MW provided by M10 to M13 (in Maalaea) That said, to comply with regional Haze rules, it is anticipated that Kahului units may need to be retired by the end of 2027.”
Alberts outlined an action plan that includes exploring ways to extend the life of Maalaea units, working with renewable energy developers to ensure their projects are installed no later than 2024, starting the permitting process for the Waena Battery Storage Project and seeking approval to establish a battery bonus program for Maui that would provide cash incentives and bill credits for adding a battery to a rooftop solar system.
“We have worked closely with developers to ensure these renewable energy projects continue to move forward,” Decker said. “Several renewable energy developers informed us that their renewable energy projects could be delayed or otherwise affected by the global supply chain crisis. They cited delays in the production of energy storage systems by battery and racking equipment, shipping delays, and cost increases for materials and labor. We do not intend to cease operation of the Kahului plant until sufficient resources to replace it are in place and operational.
When asked what would happen if Maalaea’s units were to die, Decker replied that “Given that we regularly maintain our generator sets, have been proactive in our efforts to increase our supply parts inventory and are following the steps of our action plan, we anticipate that the groups will be able to continue to supply electricity reliably.
“The impacts are unconfirmed at this stage as it would depend on new replacement generation resources coming online and the island’s power demand as we move forward,” she says.
*Colleen Uechi can be reached at firstname.lastname@example.org.