Hawaiian Electric is set to begin construction in January on Maui’s first large, standalone load-shifting battery energy storage system, marking a significant milestone in the island’s transition toward cleaner energy and reduced carbon emissions.
Known as the Waena Battery Energy Storage System (BESS), the project will support the planned retirement of four generating units at the Kahului Power Plant. The system was approved by the Hawaiʻi Public Utilities Commission in December 2023 and will be located on Hawaiian Electric-owned property along Pūlehu Road in Central Maui.
The Waena BESS is designed as a grid-connected 40-megawatt/160-megawatt-hour battery system that will store excess renewable energy and dispatch it when electricity demand is highest. Once operational, the project will play a critical role in balancing Maui’s growing portfolio of renewable resources, particularly solar and wind generation.
The battery system is part of Hawaiian Electric’s broader strategy to generate 100% renewable electricity by 2045 while steadily reducing reliance on fossil-fuel generation. Currently, renewable sources account for approximately 41% of Maui County’s electricity mix.
Anticipated to come online in 2027, the Waena BESS will connect directly to the company’s Waena Switchyard. This configuration allows the system to function as an energy-shifting resource, storing renewable power when production is high and releasing it to the grid during peak demand or periods of lower renewable output.
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The Waena Switchyard and battery system are considered a key phase in Hawaiian Electric’s plan to retire four steam-generating units at the Kahului Power Plant. These units currently provide power and grid stability to Maui’s transmission system, and their replacement requires reliable alternatives capable of maintaining system performance.
In parallel with the Waena BESS, Hawaiian Electric is working to secure additional replacement generation through large-scale renewable energy projects paired with battery storage. To date, four contracts covering both variable and firm renewable energy resources and associated battery systems on Maui have received approval from the Public Utilities Commission and are in various stages of negotiation.
Company officials say the combination of new battery storage and renewable generation will help improve grid reliability while advancing Maui’s long-term sustainability goals. By enabling cleaner energy to be stored and dispatched as needed, projects like the Waena BESS are expected to reduce emissions, support system stability, and lessen dependence on imported fossil fuels.
Construction of the Waena BESS represents one of the most significant grid modernization efforts on Maui to date and signals a continued shift toward a more resilient, renewable-powered energy system for the island.
Originally reported by MAUI Now.
