That's quite an apples and oranges comparison. I think they are e.g. basically implying, that ATMs or point-of-sale systems or any financial services at the bank counter wouldn't be needed in a Bitcoin-only world. Seems like a false premise.

Also they ignore the energy consumption of storing the blockchain. It is currently at around 400 GB, and growing exponentially. I think there are around 70 million Bitcoin users at the moment, so if everyone downloaded the full chain, as recommended, that'd be close to 30 BILLION GB of data — that's a whole bunch of flash memory to manufacture and power.

I know not nearly everyone has the full copy, but even if the number of full copies is 1 %, it's still insane.

https://www.statista.com/statistics/647523/worldwide-bitcoin...

> ABSTRACT: Bitcoin introduced a cryptographic peer-to-peer version of money that allows online payments to be sent directly from one party to another without going through a financial institution. Many recent studies evaluated and criticised Bitcoin’s energy consumption through its Proof of Work (PoW) consensus mechanism without evaluating its efficiency compared to classical electronic payment system. Based on physics, information science and economics, we compute and compare the energy consumption and define what is the energy efficiency of both the current monetary payment system and Bitcoin cryptopayment system. We demonstrate that Bitcoin consumes 56 times less energy than the classical system, and that even at the single transaction level, a PoW transaction proves to be 1 to 5 times more energy efficient. When Bitcoin Lightning layer is compared to Instant Payment scheme, Bitcoin gains exponentially in scalability and efficiency, proving to be up to a million times more energy efficient per transaction than Instant Payments.

What stood out to me is that the estimated energy consumption of ATMs was increased by a factor over 5x to account for the need to equip them with 24/7 air conditioning. I've never seen an air-conditioned ATM here in the Netherlands...

This includes the energy consumption of 47 million bank employees commuting to their work place which is 68% of the total consumption. Is the assumption that with Bitcoin local banks simply no longer exist, e.g. replaced by a decentralized set of companies (e.g. paypal has around 30.000 employees).

I'm surprised they didn't factor in the energy required to process the sewage from bank toilets.

This is pure clickbait.