Under a 20-year contract with KIUC (Kauai Island Utility Cooperative), Tesla Energy - a division of Tesla Motors - will supply batteries for a 52 MWh Tesla Powerpack lithium-ion battery storage system. According to estimates, the grid-connected system will be able to provide and distribute up to 13 megawatts of solar power on demand, day or night.
KIUC believes this way they would be able to meet the evening (from 5pm to 10pm) power demands and reduce fossil fuel use even further. According to the contract, SolarCity would charge 14.5 cents per kilowatt-hour for power from their batteries.
The project, which now only awaits approval from the Hawaii Public Utilities Commission, will be developed on 50 acres of land near KIUC's Kapaia power station. The system is being built by SolarCity, which is also chaired by Musk.
Construction work is scheduled to begin in April 2016 and is expected to be completed by the end of the year.