Plus Power’s 565MWh ‘shock absorber’ BESS in Hawaii comes online

January 11, 2024
LinkedIn
Twitter
Reddit
Facebook
Email

BESS developer and operator Plus Power has brought a 185MW/565MWh project online in Hawaii, the US, which it claimed is the “most advanced grid-scale BESS in the world”.

The Kapolei Energy Storage (KES) project on the island of Oahu was built to replace a coal plant owned by large utility AES which closed in November 2022 and previously powered a fifth of the island’s needs.

It comprises 158 Tesla Megapacks configured into 135MW/540MWh for capacity and energy use cases and another 50MW/25MWh of additional capacity for ‘fast frequency response’ to help keep the grid stable.

Brandon Keefe, Plus Power’s executive chairman claimed: “It is the first time a battery has been used by a major utility to balance the grid: providing fast frequency response, synthetic inertia, and black start. This project is a postcard from the future – batteries will soon be providing these services, at scale, on the mainland.” 

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

The announcement said it will be acting “…as an electrical “shock absorber” (a function) often served by combustion-powered peaker plants”.

Another major energy storage project which has been described as such a “shock absorber” is the 850MW/1680MWh Waratah Super Battery in Australia which is being deployed by system integrator Powin.

KES, Hawaii’s biggest energy storage project, was approved in May 2021 and financing for it was achieved by Plus Power six months later.

Customer-sited solar power has become so abundant that Hawaiian Electric, the main utility in Hawaii, needs to regularly curtail – i.e. pay owners to turn off – utility-scale solar and wind to keep the electricity system in balance. 

The utility’s modelling has forecast that thanks to the KES project it will be able to reduce curtailment of renewables by 69% over the first five years of operation, integrate 10% more new utility-scale renewables than previously modelled, and allow for continued growth in customer-sited solar. It is also expected to reduce consumer electric bills by an average of US$0.28 per month over its 20-year contract life.

The utility has been busy progressing the US island state’s clean energy and energy storage development goals, starting negotiations with 2.1GWh of energy storage projects in December 2023 and in May unveiling a long-term renewables plan which included adding add more than 3.7GW of hybrid solar, energy storage and firm renewables by 2030.

Plus Power said that by June 2024 it will have some 1,325MW/3,500MWh of energy storage online across the US, including projects which were part of a US$1.8 billion fundraise it concluded in November, the largest seen in energy storage in 2023.

Energy-Storage.news’ publisher Solar Media will host the 5th Energy Storage Summit USA, 19-20 March 2024 in Austin, Texas. Featuring a packed programme of panels, presentations and fireside chats from industry leaders focusing on accelerating the market for energy storage across the country. For more information, go to the website.

24 March 2026
Dallas, Texas
The Energy Storage Summit USA is the only place where you are guaranteed to meet all the most important investors, developers, IPPs, RTOs and ISOs, policymakers, utilities, energy buyers, service providers, consultancies and technology providers in one room, to ensure that your deals get done as efficiently as possible. Book your ticket today to join us in 2026!

Read Next

December 24, 2025
In this Energy-Storage.news roundup,  Hydrostor receives permitting approval for its California project, Hawaiian Electric is set to begin construction on a Maui battery energy storage system (BESS) and Peregrine and Wärtsilä advance construction of a Texas BESS.
December 23, 2025
The New Orleans, Louisiana, US City Council voted unanimously to approve a US$28 million virtual power plant (VPP) programme, reportedly, the first distributed energy resource (DER) programme in the city.
Premium
December 23, 2025
Energy-Storage.news Premium speaks with CEO of optimisation platform provider Ascend Analytics, Dr. Gary Dorris, PhD, about navigating ERCOT’s revenue opportunities and the implementation of RTC+B.
Premium
December 19, 2025
The board of trustees for New York Power Authority (NYPA) last week gave the greenlight for the public power organisation to develop an additional 1.2GW of storage as part of its renewed Strategic Plan for New Renewable Energy Generation. 
Premium
December 18, 2025
California Community Choice Aggregator (CCA) Clean Power Alliance (CPA) last week (8 December 2025) moved one step closer to executing agreements for offtake with two companies developing innovative thermal battery storage projects.