Energy, in the form of electricity, is how bitcoin and ethereum transactions are validated today. The faster a “miner” can solve a math problem to approve a transaction, the more likely they are to be rewarded with some of the cryptocurrency. And they do that by using a bunch of computers all working together – hence, using electricity. That’s called “proof of work” and is the original idea behind the whole crypto thing. But there’s another idea that’s been catching on – proof of stake – and one that Ethereum has been planning to adopt for quite a while (there are other cryptocurrencies that already use this method). In proof of stake, a prospective validator puts up a stake (a given amount of the cryptocurrency) then one of the prospective validators is chosen algorithmically to validate the transaction. Once validated, another group (“attestors”) confirms and accepts the validation. This is an asttempt to rein in the massive electricity use.
Read more about it at https://www.technologyreview.com/2022/03/04/1046636/ethereum-blockchain-proof-of-stake if you’re interested.