Ethereum (ETH): After its transition to Proof-of-Stake (the "Merge" , Ethereum's energy consumption decreased dramatically (by over 99%). This makes it a much more environmentally friendly option. Sustainable crypto investment

Cardano (ADA): Designed from the ground up with energy efficiency in mind, Cardano utilizes a PoS mechanism called Ouroboros.

Solana (SOL): Solana uses a variation of PoS called Proof of History (PoH) in combination with Proof of Stake, which results in high transaction speeds and low energy consumption.

Algorand (ALGO): Algorand uses a Pure Proof-of-Stake (PPoS) consensus mechanism, which offers security and scalability while minimizing energy usage.

Polkadot (DOT): A multi-chain protocol that uses Nominated Proof-of-Stake (NPoS), designed to be efficient and interoperable.

Avalanche (AVAX): Avalanche uses a Proof-of-Stake consensus mechanism for its primary network and allows for the creation of subnets with custom consensus rules, enabling eco-friendly options.

Tezos (XTZ): Tezos employs a Liquid Proof-of-Stake (LPoS) mechanism known for its energy efficiency.