Musk is a liar and a manipulator. I wouldn't trust a word he says. He claimed that Tesla would start accepting bitcoin once 50% of bitcoin mining is from renewable sources and it hit 54% in January but Tesla ignored that because it was all bullshit.
Other cryptocurrencies are also used for computing power mining, such as ETH, which is also a kind of energy consumption.
Ethereum operates on a Proof-of-Stake model, which means that unlike Proof-of-Work cryptocurrencies, it consumes no energy overall.
It used to be a proof of work coin for years, so it's not like they're suddenly a green coin. It's been barely 8 months since it switched to PoS.