July 23 2021: -On Wednesday, Tesla CEO Elon Musk said that his electric vehicle and solar business could help bitcoin miners switch to renewable energy, but is limited by a tight supply of battery cells.

He also said that Tesla is still not manufacturing its custom-designed 4680 cells for commercial use in electric cars or energy storage systems.

Tesla has been selling commercial and residential solar installations since acquiring SolarCity in 2016 for around $2.6 billion, a deal that landed Musk in a Delaware court this month.

But before it got into the solar business, Tesla created and started selling energy storage products in 2015, which include a backup battery for homes called the Powerwall and bigger batteries that can store solar or wind energy generated intermittently. Hence, it is available for use whenever utilities need it.

Tesla has a number of these utility-scale energy storage systems, and Musk reminded his audience on Wednesday that it has helped utilities with “load-leveling the grid,” that include in South Australia and elsewhere. But he that battery production was currently constraining production.

“The limiting factor for us is cell production. So we need to both internally get our Tesla internal battery cells produced and raise supply from suppliers.”

Musk also said that even once Tesla can make its battery cells, it will still rely on other battery cell makers. Its current cell suppliers included Panasonic, LG, and CATL.

“Generally, when I talk to our suppliers and they say ‘how many cells would you like?’ I say, ‘how many cells can you make?’ you know because sometimes they’re concerned, will Tesla compete with them on cells? I’m like a no-no if you want to make the cells be our guest. It’s just that we need a crazy number of batteries.”

In a Twitter exchange with fans after the bitcoin conference, Musk wrote that Tesla is still “not quite done” getting to “volume production” of its custom-designed 4680 battery cells.

He acknowledged the fact that Tesla sold Maxwell Technologies’ ultra-capacitor business and other assets to a San Diego-based startup called UCap Power, which Gordon Schenk leads, previously Tesla’s VP of sales for its Maxwell division.

Initially, Tesla acquired Maxwell in 2019 in a deal valued at over $200 million. The same terms of the sale to UCap Power Inc. were not disclosed but discussed when Tesla holds its second-quarter earnings call on Monday, July 26.

At The B Word conference, Finally, Musk added that energy storage systems, combined with solar and wind were not the only ways to transition bitcoin to cleaner energy. He is also endorsing existing hydropower, geothermal and nuclear power to reduce the environmental impact of bitcoin mining.