SolarCity to Build Dispatchable System in Kaua’i

This 12 megawatt Koloa solar array owned by Kauai Island Utility Cooperative was built by SolarCity and went into operation in 2014. SolarCity plans to build a larger array at Kapaia with a unique battery energy storage system. Photos by Kauai Island Utility Cooperative (PRNewsFoto/SolarCity)

Kaua’i Island Utility Cooperative (KIUC) and SolarCity have entered into a power purchase agreement (PPA) for what is believed to be the first utility-scale solar+storage system specifically designed to power the grid during peak evening demand time.

The project is slated to be built next to KIUC’s Kapaia power plant. For an island that already gets up to 95 percent of its daytime energy from the sun, the placement is a logical choice.

Prior to recent improvements in storage technology, solar has not been considered to be a dispatchable resource. The proposed plant aims to dispel that notion. The 52 MWh battery system is expected to feed up to 13 MW of electricity onto the grid to meet the evening peak in demand, from 5 p.m. to 10 p.m. This is expected to significantly reduce the use of fossil fuels as well as cut greenhouse gas emissions.

“SolarCity is excited to bring the first dispatchable solar storage system to the island of Kaua’i. Hawai’i has been and continues to be at the forefront of new technology and research for solar and storage,” said Jon Yoshimura, Director of Policy and Electricity Markets for SolarCity. “This solution will allow for more efficient load balancing and will reduce dependence on fossil fuel-based power.”

Hawaii’s power costs are the highest in the country. The agreement with SolarCity should help with that. Kaua’i Island Utility Co-operative will pay SolarCity 15.5 cents/kWh. While this is slightly higher than what the co-op pays for solar from its 2 daytime solar plants, it is still significantly lower than the cost of fossil fuels.

“KIUC has been investigating energy storage options for more than two years and price has always been the biggest challenge,” said David Bissell, President and CEO of KIUC. “This is a breakthrough project on technology and on price that enables us to move solar energy to the peak demand hours in the evening and reduce the amount of fossil fuel we’re using.”

KIUC has requested an accelerated timetable for approval by the Hawai’i Public Utilities Commission in order to qualify for the federal investment tax credit. This will also cover the cost of storage if it is installed at the same time as the PV system. To qualify, construction must begin by April of next year to be in operation by the deadline of December 2016. 


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