Tesla is working on a bid to deploy one of the biggest battery systems in the world with 244 Megapacks, Tesla’s latest giant battery system, on a Hawaiian island.

After a lot of rumors and anticipation, Tesla launched its “Megapack” last year.

It’s the company’s latest energy storage product, after the Powerpack and the Powerwall, and it is meant as an even bigger option targeting electric utility projects.

According to Tesla, a single Megapack has up to 3MWh of storage capacity and a 1.5MW inverter.

Tesla CEO Elon Musk asked utilities to buy the new Megapack to replace polluting and inefficient peaker plants.

Some electric utilities have started taking Musk up on his offer as we started hearing about several new Megapack deployments over the last few months.

Now we learn of a giant new project that Tesla is bidding on with the Megapack in Hawaii.

Hawaiian Electric, Hawaii’s biggest electric utility serving 95% of the state, is developing a massive energy storage project in Kahe Valley, O‘ahu.

The goal is to provide both load-shifting services and create backup power to its electric grid:

Load-shifting: Stores energy during periods of low customer demand, for use during early-morning hours and at night when electricity demand is at its highest. This type of BESS enables the electric grid to accommodate more renewable sources, such as solar and wind, while it displaces thermal generation and helps lower emissions.

Contingency: Allows stored energy to be sent to the grid as a quick response to an unexpected event such as a sudden drop in energy production from wind, solar, or a thermal power plant. This quick-response capability improves grid reliability and reduces the likelihood of customer outages.

They have been taking proposals since last summer and Tesla’s proposal to use Megapacks for the project appears to be one of the frontrunners.

Hawaiian Electric released an environmental assessment draft for Tesla’s project (hat tip to Daniel A.).

With a planned capacity of 810MWh, the project would become one of the biggest batteries in the world:

The proposed project consists of a grid-tied BESS capable of storing 810 megawatt-hours (MWh) of energy and discharging it at a rate of 135 megawatts (MW). In addition to the batteries, the BESS project will include inverters and transformers, concrete pads, underground cables and ducts, switchgear, and other electrical infrastructure. The BESS site is close to the existing 138 kilovolt (kV) transmission switchyard at KGS, allowing for strategic interconnection. Depending on the final design, some relocation of existing 138kV transmission or 46kV sub-transmission lines may be required. Work within the existing switchyard related to interconnections will include limited new equipment and structures similar to those already present within the switchyard.

To put it into perspective, it would have more than six times the energy capacity of Tesla’s 100MW/129MWh Powerpack project in South Australia, which was the biggest battery in the world when it was completed a few years ago.

Tesla’s proposal consists of deploying 244 Tesla Megapacks:

The project will include approximately 244 Tesla Megapack containerized grid energy storage batteries, each with an approximately 3MWh capacity, designed for utility-scale power storage. Each Megapack is equipped with liquid-cooled lithium-ion batteries for energy storage; a circuit breaker panel/customer interface bay; DC-to-DC converter units to step up the voltage; a 675kVA inverter that converts DC stored in the battery to AC used on the Company grid; and a thermal management system. The equipment is packaged as a single unit in a shipping container-type housing referred to as the IP66 enclosure.

Here are some of the plans for the project:

According to the electric utility, the project will cost between $200 and $300 million:

Hawaiian Electric, which is funding the project, anticipates that the total value of the project will be between $200 and $300 million.

A final decision to move forward with the project is expected in May.

If chosen, Tesla will be expected to start construction in March of next year in order for the system to go into operation in 2022.

Tesla is currently working on several other major Megapack projects, including one in Northern California with PG&E.

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