Hawaiian Electric is getting ready to put some serious batteries in the ground on Maui. The utility says it will break ground in January on the island's first large standalone battery system, the Waena Battery Energy Storage System. The 40-megawatt/160-megawatt-hour installation will sit on company-owned land along Pūlehu Road and is meant to grab excess midday solar and wind power, then send it back onto the grid when demand peaks. Company officials say the project is expected to support the planned retirement of four steam-generating units at the Kahului Power Plant while helping keep the island's grid steady.
In a Dec. 17 news release, Hawaiian Electric said construction is expected to begin in January and that the Waena BESS will tie into the Waena Switchyard. The utility describes the project as a load-shifting resource that can store large amounts of renewable energy and dispatch it later when customers are using the most power.
What Waena Will Do For Maui's Grid
The Waena BESS is designed as a load-shifting battery that can bank excess solar and wind when production is high and release that energy during the evening or whenever renewables dip. Maui Now reports that this capability is central to plans to retire four steam-generating units at the Kahului Power Plant while preserving system stability.
Funding, Permits and Timeline
The project received regulatory clearance in 2023, and company filings show regulators approved cost recovery under an Exceptional Project Recovery Mechanism. An SEC filing from Hawaiian Electric indicates a planned commitment estimate in the tens of millions as the utility prepared the site and interconnection work.
Hawaiian Electric says the Waena site is on company-owned property along Pūlehu Road and that prior Waena Switchyard work has already set up the grid for the new interconnection. The company notes the system is anticipated to come online by 2027 and says the project is part of its broader goal of reaching 100% renewable electricity by 2045, with construction expected to start in January. Hawaiian Electric provided those details in its release.
Where This Fits In Maui's Clean-Energy Push
Maui has already added large utility projects in recent years, including AES’s Kūihelani solar-plus-storage plant, which began operations in June 2024 and includes a 240 MWh battery that helped reduce reliance on imported oil, Reuters reported. Hawaiian Electric also says four contracts for additional renewable and battery projects on Maui have PUC approval and are in various stages of negotiation, Maui Now reports.
Residents can expect construction activity near Pūlehu Road as crews build foundations and move equipment, and utility officials say the BESS is expected to cut Maui's reliance on imported fuel and give grid operators more flexibility to balance supply and demand. Hawaiian Electric has not released a contractor list or a detailed construction schedule beyond its January start window, and the utility says it will share further updates as work moves ahead.
