It relates to what I mentioned previously, which is the type of blockchain you're using. As a proof-of-work blockchain, Bitcoin uses the same amount of energy as Switzerland. If you're using a proof-of-stake blockchain, you are not using that level of energy. If you're using a proof-of-history blockchain, you are not using that level. Not all blockchains are created equal. It depends on the working mechanism behind the blockchain and how you're proving the transactions are true.
In proof-of-stake blockchains, you have to bond the money in order for you to be a validator. I can send more information to the committee after regarding this, but essentially that means they have different security issues. There are different ways they can be attacked.
For proof of work, you would have to buy half the miners to take over the network. Proof of stake is different; you would have to own over half the value of the currency to control the network.
Both disincentivize cheating. Both work, but the energy efficiency behind them is different. Proof of stake and proof of history consume...I don't know what the statistics are compared to the banking sector, but it's not what it was 10 years ago, as my colleague mentioned. The technology has advanced.