A 33,000-member electric power cooperative on the island of Kauai in the Hawaiian archipelago is emerging as a leader as it moves from fossil-based power generation to renewables, and deploys what ranks as one of the world’s largest arrays of lithium-ion battery packs.
The battery storage became operational in March and is expected to make solar power produced during the daytime available to customers well into peak demand periods after sunset.
Tesla Motors Inc., in association with Kauai Island Utility Cooperative (KIUC), deployed the battery storage using a design derived from the Tesla Model S vehicle. The 272 Powerpack energy storage units are sited at a solar farm whose 55,000 photovoltaic panels have a generating capacity of 13 megawatts (MW).
Under terms of the deal with Tesla, KIUC will buy power for 20 years at the rate of 13.9 cents per kilowatt-hour (KWh). The 52 MWh battery system is design to feed up to 13 MW of electricity onto the grid. Doing so is expected to shave the amount of conventional power generation needed to meet the evening peak, which lasts from 5 p.m. to 10 p.m.
KIUC President and CEO, David Bissell says the cost is lower than that incurred to buy power from diesel-fueled power plants and is below the charge paid by electricity customers elsewhere in the state.
The battery storage is expected to make solar power available well into the evening.
The solar-plus-battery facility means that KIUC has achieved roughly 44% renewable generation, says Bissell. “This is truly remarkable when you consider that as recently as 2011 we were 92% dependent on fossil fuel generation,” primarily diesel and naphtha. (Read more.)