Proof of Stake blockchains use up to 99.99% less energy
than Proof of Work blockchains like Bitcoin. These networks are secured by staking tokens and their electricity expenditures are limited to renting virtual machines for nodes.
For example, Ethereum's Proof of Stake version will use 1/10,000th the energy than the current Proof of Work Ethereum network, according to Danny Ryan
, a researcher at Ethereum Foundation.