Hawaiian Electric plans to develop the 40 MW / 160 MWh Waena Battery Energy Storage System on Maui, the island’s first large standalone load-shifting battery. Approved by the Hawaii PUC in December 2023, the grid-connected project is scheduled to begin construction in 2026 and enter commercial operation in 2027, supporting renewable integration and grid reliability.
DATA SNAPSHOT
U.S.-based regulated electric utility , Hawaiian Electric, has advanced plans to construct the 40 MW / 160 MWh Waena Battery Energy Storage System on the island of Maui. The project represents Maui’s first large standalone load-shifting battery facility. The project received approval from the Hawaii Public Utilities Commission (PUC) in December 2023, with construction scheduled to start in January 2026. Commercial operation anticipated in 2027, as part of planned changes to Maui’s electricity supply mix.
The Waena BESS is a grid connected system, located on Hawaiian Electric-owned land along Pulehu Road in Central Maui and interconnected through the Waena Switchyard. The system has been designed as a standalone asset, not directly paired with single renewable generation facility. The system will be capable of storing electricity generated from variable renewable sources, including solar and wind, and dispatch electricity during periods of higher demand.
Integration with the Waena Switchyard is central to the project’s role in the transmission network. This configuration allows the battery system to support load shifting and grid operations while maintaining system reliability. The Waena BESS also forms part of the infrastructure enabling the planned retirement of four steam-generating units at the Kahului Power Plant, which currently contribute energy and system stability on Maui.
Maui County currently sources about 41% of its electricity from renewable resources. In parallel with the Waena project, Hawaiian Electric is progressing additional renewable energy and battery storage developments, including four PUC-approved contracts that are moving through negotiation and development stages. The Waena BESS aligns with Hawaiian Electric’s long-term power system planning, which outlines a gradual increase in renewable electricity supply through 2045.