SolarCity has selected Tesla Energy to supply the batteries for a solar array and energy storage system to be built for Kaua’i Island Utility Cooperative (KIUC) in Hawaii. KIUC says SolarCity says it made its choice after conducting a comprehensive competitive solicitation in the battery marketplace.
According to the utility, the 52 MWh Tesla Powerpack lithium-ion battery storage system will feed up to 13 MW of electricity onto the grid to “shave” the amount of conventional power generation needed to meet peak demand in the evening from 5 p.m. to 10 p.m. By using the solar energy stored in the battery instead of diesel generators, KIUC will reduce its use of imported fossil fuels and also cut its greenhouse-gas emissions.
Under the terms of the 20-year contract announced in September 2015, KIUC will pay SolarCity 14.5 cents/kWh, only slightly more than the cost of energy from KIUC’s two existing 12 MW solar arrays, whose output is available only during the day.
The array and battery storage facility will be built on 50 acres of land owned by Grove Farm Company Inc. adjacent to KIUC’s Kapaia power station off Ma’alo Road, just north of Lihu’e.
The project has already received most of its required state and county approvals and is now awaiting approval by the Hawaii Public Utilities Commission. KIUC and SolarCity have requested an accelerated timetable for review of the project so that construction work can begin by April, with a goal of being in commercial operation by the end of 2016.