Hawaii replaces its last coal plant with a Tesla battery system

Hawaii’s goal of being 100% powered by green energy technology by 2045 may be getting a significant push forward. Following the closure of its last remaining coal plant in 2022, the Aloha State will now be utilizing a Tesla Megapack battery system installed by energy company Plus Power to deliver electricity to its grid.

“This project provides another example of Hawaii’s leadership in the clean energy transition,” said Mark B. Glick, Hawaii’s chief energy officer. “The grid modernization strategies employed by Plus Power support a cleaner, more reliable and more affordable energy system.”

Situated across eight acres on the island of Oahu near the capital city of Honolulu, the facility boasts 158 Megapack battery systems, each comparable in size to a standard shipping container. This newly implemented technology matches the electric output of the retired coal plant, with Tesla saying it is the “most advanced grid-scale battery energy storage system in the world.”

“This is the first time a standalone battery site has provided grid-forming services at this scale,” said Mike Snyder, the senior director at Tesla Megapack. “This is a critical application for high renewable penetration grids supplied by 185 MW of Megapack inverters.” 

The tropical climate of Hawaii, renowned for its sunny skies and ideal tourist destinations, is also conducive to harnessing solar energy. However, the state’s previous grid infrastructure was unable to store much of the surplus power generated from solar panels, resulting in cleaner electricity going to waste.

The state’s Megapack battery project aims to address that issue with additional storage that reduces the amount of unused renewable energy by nearly 70%. This system also has the ability to hold onto additional reserve energy to use in the case of grid outages caused by severe weather or natural disasters.

“This is a landmark milestone in the transition to clean energy,” said Brandon Keefe, Plus Power’s executive chairman. “It’s the first time a battery has been used by a major utility to balance the grid: providing fast frequency response, synthetic inertia, and black start. This project is a postcard from the future — batteries will soon be providing these services, at scale, on the mainland.” 

According to Hawaiian Electric, this technology is expected to save consumers around 28 cents per month, but further reductions to the electric bills of Hawaiians could be coming. Future cost-saving green energy projects plan to rely on the battery system when they eventually come online.