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Tesla’s massive 1GWh Megapack battery project with PG&E is approved

Tesla’s massive project to deploy 1GWh of Megapacks to create a giant energy storage system in California with PG&E has received approval from the local authorities.

We first learned of the project at PG&E’s Moss Landing substation when they submitted it to CPUC and the company was in talks with Tesla in 2017.

It involves four separate energy storage projects and two of them should become the world’s largest battery systems.

Dynegy is going to deploy a 300MW / 1,200MWh project on PG&E’s grid while the Tesla project will be a 182.5MW / 730MWh, which could eventually go up to 1.1GWh.

In 2018, we obtained Tesla’s proposal for the project and it shows that the company plans to use ‘Megapack’ instead of its usual Powerpack for large utility-scale projects.

According to the document, a Tesla Megapack consists of long 23′-5″ (7.14m) x 5′-3″ (1.60m) battery system, which the company mostly installs back to back with another unit:


That was even before Tesla unveiled its new massive energy storage product last year. Now we know that the Tesla Megapack can have an energy capacity of up to 3MWh.

According to Tesla’s plan, they will deploy 449 Megapacks at the site:

tesla megapack

Tesla is listing the project as having a total capacity of 1,200MWh, which would mean that each Megapack has a capacity of 2,673kWh.

That’s more than 12 times the capacity of Powerpack 2 in a package that could potentially fit about 8 Powerpacks.

The total capacity of those 449 Megapacks represents more energy capacity than Tesla Energy deployed throughout its first 3 years of operation – all Powerpacks and Powerwalls combined.

The California Public Utilities Commission approved the project just over a year ago and along with 3 other energy storage systems, the new energy storage capacity is so important that it will replace three gas power plants.

However, the project still needed a few other greenlights before moving forward.

Now Tesla’s giant new battery project with PG&E has been approved the Monterey County Planning Commission, which should allow it to start construction soon.

Local News reported:

“Wednesday morning the Monterey County Planning Commission unanimously approved a joint project between Tesla and PG&E to build a facility that will store wind and solar power and then make it available for use during periods of high energy demand.”

Monterey County Supervisor John Phillips commented on the announcement:

“It’s huge for the area and as you know the power plant has been gradually shutting down and they producing about one-tenth of the power they used to produce in the past and that hurts us from a tax standpoint,”

Tesla ‘s proposal originally stated that it aimed to complete the project by the end of 2020. With the new approval, Tesla and PG&E aim to break ground next month and still hope to be done for the end of the year.

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