Hawaiian Utility to Stabilize Grid with 565 MWh Battery System

Hawaiian Utility to Stabilize Grid with 565 MWh Battery System


Renewable Energy Curtailment Minimization with Tesla Megapacks in Hawaii

A large grid-scale energy storage project in Hawaii, featuring Tesla Megapacks, could potentially minimize the curtailment of renewables output.

Introduction to Kapolei Energy Storage (KES) Facility

From pv magazine USA

Plus Power has started operating its Kapolei Energy Storage (KES) facility on Oahu, Hawaii, helping the state in its transition from fossil fuels to solar and wind.

KES Project’s Impact on the Hawaiian Electric Grid

The KES project adds 135 MW/540 MWh to the Hawaiian Electric grid, with an additional 50 MW/25 MWh of additional “fast frequency response” to support grid stability.

Advanced Battery Features and Grid Stabilization

The advanced battery has “virtual inertia” to replicate the power-smoothing function of a conventional spinning turbine. It has “black start” capabilities, which supports grid recovery in the event of a blackout.

First-of-its-Kind Battery Use by a Major Utility

“It’s 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,” said Brandon Keefe, executive chairman, Plus Power.

The Physical Layout of the Kapolei Energy Storage Facility

Located on 8 acres of industrial land on the southwest side of Oahu, the project is comprised of 158 Tesla Megapack 2 XL lithium-ferro-phosphate batteries, each about the size of a shipping container.

Performance Advantages of Batteries Over Combustion-Powered Plants

The battery can serve as a grid “shock absorber,” serving a role normally performed by combustion-powered plants. It can respond to grid signals in 250 milliseconds, far faster than the several minutes that conventional power plants take to fire up.

Essential Role of Energy Storage Technology in Grid Management

“Energy storage technology that responds quickly to constantly changing conditions is an essential tool for us to use to manage the grid and operate it as efficiently as possible,” said Jim Alberts, senior vice president and chief operations officer, Hawaiian Electric.

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Reducing Curtailment and Improving Grid Efficiency

Solar power has become abundant, leading Hawaiian Electric to have to curtail, or turn off, large volumes of utility-scale solar and wind to keep the system in balance. The new energy storage capacity is expected to allow the utility to reduce renewable energy curtailments by 69%. It is also expected to enable 10% more new utility-scale renewables on the grid than previous models allowed.

Financial Savings for Electric Customers

Hawaiian Electric said it expects the battery to save its customers on electricity bills. The utility estimates the battery will reduce electric bills by $0.28 per month over its 20-year contract life.

Strategic Battery Plant Interconnection and Emergency Response

The KES battery plant is interconnected near three of Hawaiian Electric’s critical power generation facilities, enabling a rapid reboot of those power plants in the event of an island-wide emergency. This is known as “black start” capability.

Closure of Coal-Fired Power Plant and Transition to Cleaner Energy

The batteries will help replace grid capacity formerly provided by an AES coal-fired power plant less than a mile away. The plant used to provide about 20% of Oahu’s electricity, home to nearly one million residents. The plant closed in September 2022.

Future Developments by Plus Power

Project developer, owner, and operator Plus Power has a development portfolio of over 10 GW of projects in transmission queues across 28 states and Canada. It has over $1.8 billion in project financings announced as of October 2023. The company expects to be operating seven additional large-scale energy storage plants across Arizona and Texas, adding 1325 MW / 3500 MWh of storage by June 2024.

Project’s Contribution to Clean and Reliable Electricity

“Our projects, like KES, help our customers provide affordable, reliable, clean electricity on hot summer afternoons and cold winter nights, while enabling the decarbonization of the electric grid,” said Keefe.

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