Dive Brief:

Large energy storage projects paired with solar are key to Kauai Island Utility Cooperative (KIUC) reaching its renewable goals — the utility expects to reach 70% by the end of next year.

Last week, the Hawaii Public Utilities Commission (PUC) approved a 19.3 MW solar facility and 70 MWh battery energy storage system to be located on the Pacific Missile Range Facility. AES Distributed Energy will build the project on land leased from the Department of Defense.

Also last week, KIUC and Tesla opened a new 13 MW solar project and 52 MWh battery energy storage system. Earlier this year, the small electric cooperative announced that new resources would allow it to accelerate the schedule for meeting its renewable energy goals.

Dive Insight:

As recently as 2011, more than 90% of KIUC's energy was coming from diesel generation. But with a big boost from battery storage the island is now accelerating its plans to transition away from fossil fuels.

In February, the KIUC board updated the cooperative's energy goal to 70% renewable energy by 2030. The state as a whole is targeting 100% renewable energy by 2045.

The cooperative said the new storage and solar projects "are moving us rapidly closer to our renewable goals," and by the end of next year the utility "will be able to supply roughly 65% of Kauaʿi’s night time peak load with stored solar generated energy."

The island's rapid shift in course highlights the impact batteries can have, particularly in turning solar into a more flexible resource. The utility held a "blessing of the state’s first dispatchable solar energy plant" in March, which also includes a 52 MWh battery energy storage system.

The solar+storage facility approved last week by the PUC is expected to displace the need for 2.8 million gallons of diesel annually and will power about 6,000 homes. The cooperative said it will also be one of its lowest-cost power sources: KIUC signed a 25-year power purchase agreement with AES at a price of $0.1085/kWh.

It is the third storage project the cooperative has developed.