Hawaiian Electric Plans Nearly 1 Gigawatt-Hour Of Battery Storage, Mostly From Tesla Megapacks

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The state of Hawai’i has set a goal of getting 100% of its electricity from renewable energy sources by 2045. Clearly, in order to reach that goal, grid-scale battery storage will be required. Now Hawaiian Electric, which supplies electricity to 95% of Hawai’i residents, says it is looking at installing up to 1 gigawatt-hour of battery storage.

Hawaii coastline
Hawaiian coastline courtesy of Blue Planet Foundation

According to the Honolulu Star Advertiser, a major portion of that storage may be supplied by 244 Megapacks from Tesla located on 6 acres of land adjacent to its Kahe power plant in Nanakuli. Other smaller storage facilities are planned for other locations on Oahu, Maui, and Hawai’i.

The Tesla Megapack was introduced last year and has a maximum capacity of 3 megawatt-hours (MWh). Tesla says it takes up 40% less space than a conventional battery storage system would need. “Every Megapack arrives pre-assembled and pre-tested in one enclosure from our Gigafactory — including battery modules, bi-directional inverters, a thermal management system, an AC main breaker and controls. No assembly is required, all you need to do is connect Megapack’s AC output to your site wiring.” With regard to that last point, Hawaiian Electric has carefully chosen the location for the Megapacks so it will be next to an existing major grid connection point.

Tesla Megapack
Image credit: Tesla

244 Megapacks would provide up to 732 MWh of storage. No cost information is available, but online sources suggest each Megapack is priced at between $600,000 and $900,000. If and when the installation is completed, it will easily rank as the largest battery storage facility in the world and would be 7 times larger than the Hornsdale battery that Tesla provided to South Australia in 2018.

Hawaiian Electric last August asked for bids on about 900 megawatts of new renewable energy installations on Oahu, Maui, and Hawai’i islands. It will be the largest and most ambitious renewable energy initiative in the history of the state.

Tesla Megapack
Image credit: Tesla

Jeff Mikulina, executive director of the Blue Planet Foundation, tells the Star Advertiser it’s exciting to see such a large scale storage system plan that complements smaller storage systems connected with upcoming renewable power generation projects and rooftop solar where storage has become commonplace. “We all know that storage is an integral part of achieving our 100% renewable energy future,” he says.

The push for renewables is resulting in the closure of Hawaiian Electric’s coal-fired AES Hawaii generating station at the Campbell Industrial Park by September, 2022. It is the largest single producer of electricity in the state, meeting 16% of peak demand. The renewable energy projects it proposes are designed to replace the electricity from AES Hawaii after it goes off line.

Tesla Megapack
Image credit: Tesla

In addition to the 244 Tesla Megapacks, Hawaiian Electric proposes a 135 MWh battery storage installation in Kahe, a 65 MWh battery at the Campbell Industrial Park, a 40 MWh battery on Maui, and two systems on the island of Hawai’i with a combined capacity of 18 MWh. That’s a total of 258 more megawatt-hours in addition to the 732 MWh available from the Tesla system. Add it all up and it comes to 990 MWh. Not quite one gigawatt-hour, but pretty darn close. Well played, Hawaiian Electric.

Edit: The original version of this post stated the size of the battery storage as 1 terawatt-hour, which has now been corrected to 1 gigawatt-hour.

Hat Tip To Andrea Bertoli.

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Steve Hanley

Steve writes about the interface between technology and sustainability from his home in Florida or anywhere else The Force may lead him. He is proud to be "woke" and doesn't really give a damn why the glass broke. He believes passionately in what Socrates said 3000 years ago: "The secret to change is to focus all of your energy not on fighting the old but on building the new."

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