Tesla beat 90 other competitors to win a contract for a massive 100 MW/129 MWh energy storage system in Australia, which they promised to deliver in 100 days.

That’s a bigger and more powerful energy storage system than anything else in operation today.

CEO Elon Musk gave some insights into Tesla’s plan to make it happen and surprisingly, Samsung is involved.

Panasonic has long been Tesla’s main battery cell supplier and it remains the sole battery cell supplier for its vehicles.

Tesla is importing Panasonic 18650 li-ion cells from Japan for Model S and Model X battery packs and the Japanese manufacturer is also producing 2170 Model 3 battery cells under Tesla’s roof at Gigafactory 1 Nevada.

But when it comes to energy storage products, like Powerwalls and Powerpacks, Tesla has also turned to other battery cell manufacturers. Though Panasonic has also been a supplier for those products.

When Tesla announced the start of battery cell production at Gigafactory 1 during the first quarter of 2017, the company said that the cells would be used in their energy storage products since Model 3 cells were not planned until later in the year.

In its latest SEC filing, Tesla disclosed that they have approved other battery cell suppliers for energy storage products:

“Our business is dependent on the continued supply of battery cells for the battery packs used in our vehicles and energy storage products. While we believe several sources of the battery cells are available for such battery packs, and expect to eventually rely substantially on battery cells manufactured at our own facilities, we have to date fully qualified only a very limited number of suppliers for the cells used in such battery packs and have very limited flexibility in changing cell suppliers.”

Last year, a shipment of Samsung SDI cells was received by Tesla and the company disclosed that they were evaluating the use of the cells for their energy storage products.

On a conference call hosted by Goldman Sachs for bondholders following Tesla’s new bond issuance earlier this week, Musk said that Tesla would actually use Samsung cells in the Powerpacks for the major project in South Australia, according to sources who were on the call.

That’s a significant project to partner on with Samsung since it represents more energy capacity on a single project (129 MWh) than Tesla delivered in all its Powerpack projects combined during the entire last quarter (97 MWh).

While Korea-based Samsung SDI is making the cells, Tesla is still building the Powerpacks for the project at the Gigafactory in Nevada.

On the same call, Musk expressed concerns about battery cell supply potentially creating a bottleneck for Model 3 production, which is Tesla’s main focus right now.

Electrek’s Take

Since Tesla is buying all of Panasonic’s output at Gigafactory 1, it would make sense to focus production on Model 3 battery cells during the production ramp.

As for the partnership with Samsung, Tesla built its latest battery architecture around a new ‘2170’ battery cell format and Samsung unveiled its own new ‘2170’ battery cell earlier this year.

Lucid Motors announced that they would be using the cells, of course they can use the same format with different chemistry, and claimed that they would have the best energy density.

Though Musk also claimed that Tesla’s 2170 battery cells produced by Panasonic at Gigafactory 1 have the highest energy density.

It’s certainly interesting to see Tesla, which is currently the biggest li-ion battery consumer in the world, expanding its battery supply chain.

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