Ethereum already has a Proof-of-Stake (PoS) chain and it's running in parallel to the current PoW chain. It's now called the Beacon Chain (formerly ETH 2.0) and it will become the default consensus mechanism for Ethereum after The Merge (possibly already in Q2). In PoS, instead of miners you have validators. Validators stake 32 ETH ($150k) to be able to produce and attest blocks and earn staking rewards for their efforts. If they go offline or act maliciously they get penalized/slas...