Hawaiian Electric's battery storage project on Maui hit a build milestone, a small win for the island's shift away from fossil fuels.

• Six Tesla megapacks are now installed at the Waena storage site in central Maui.
• Each unit is about the size of a 40-foot shipping container, giving the island serious backup power.
• Battery storage matters more as Maui leans on solar and wind, which only produce part of the day.
• Hawaiian Electric is aiming to run entirely on renewable power by 2045.

Outlook: More storage capacity should come online as the utility works toward its 2045 target.