SolarCity signed a contract with Kaua’i Island Utility Cooperative (KIUC) to provide energy from a utility-scale solar project with battery storage during evening peak. The companies believe the project is the first utility-scale solar system in the United States to provide dispatchable solar energy.

Key Details

• The project will consist of a 17-MW solar array and a 52-MWh battery system
• KIUC will purchase energy for 14.5 cents/kWh through a 20-year power purchase agreement
• The rate is lower than the current cost of conventional generation and only “slightly more” than the cost of energy from two existing 12-MW solar projects without battery storage
• Energy will be provided during KIUC’s evening peak, which occurs from 5 PM to 10 PM
• Construction of the project must begin by April 2016 in order to reach commercial operation by December 31, 2016 and qualify for the 30% federal investment tax credit

Implications

Cost reductions in solar and battery storage have resulted in an economically viable utility-scale solar and battery storage project in Hawaii. When operational, the system should transform an intermittent solar resource into a firm, dispatchable power source. Solar and battery storage systems could become more common if technology costs continue to decline.

More Information

KIUC Press Release: Kaua’i Utility Signs Deal With SolarCity for First Dispatchable Solar Storage System

GTM: Utility-Scale Solar in Hawaii, Batteries Included