Hawaiian Electric’s Kapolei Energy Storage is expected to reduce the wastage of surplus clean electricity by 69% in its first five years of operation. It also has the capability to provide “black-start” power to restart the grid in the event of a disaster. The batteries are located near a substation connected to three other power plants, allowing them to jump-start those plants if needed. The combination of these capabilities makes Kapolei the most advanced battery energy storage facility in the world. The project is a significant step in Hawaii’s transition to clean energy and showcases how critical grid functions can be shifted from fossil-fueled plants to clean energy plants.
https://www.canarymedia.com/articles/energy-storage/a-huge-battery-has-replaced-hawaiis-last-coal-plant