The comparison set includes public distributed ledger (DLT) systems that share the critical common denominator of using proof-of-stake (PoS) based consensus. In PoS, consensus nodes are selected at random from the pool of users which staked the network’s native cryptocurrency above the minimum and with a probability of selection weighted by stake.
Algorand uses a "Pure-Proof-of-Stake" (PPoS) system where relay nodes store the entire ledger and non-relay nodes store up to approximately 1,000 blocks.
Avalanche consists of three individual blockchains: the "X-Chain", "C-Chain", and "P-Chain". Each chain uses a different consensus mechanism based on its distinct purpose.
Cardano is the only "Unspent Transaction Output" (UTXO)-based system in the comparison set. In Cardano, nodes store every transaction ever made.
Ethereum is a commonly used blockchain that transitioned from "Proof-of-Work" to "Proof-of-Stake".
In Hedera, “Proof-of-Stake” (PoS) is used to protect the network via a virtual-voting algorithm. Token holders stake Hedera’s native cryptocurrency to nodes, adding weight to a node’s voting power.
NEAR uses a variation of the "Proof-of-Stake" (PoS) consensus mechanism that is based on two rounds of consensus, where a block is considered finalized when it has received the first communication round.
In Polkadot’s “Nominated-Proof-of-Stake” (NPoS), each node delegates stake across 16 consensus nodes, among which the stake is divided equally.
Solana combines "Proof-of-History" (PoH) and "Proof-of-Stake" (PoS) consensus mechanisms, where the former processes transactions and the latter processes them.
In Tezos’ “Liquid-Proof-of-Stake” (LPoS) consensus mechanism, token holders delegate their processing rights to other token holders (called consensus nodes) without transferring ownership of their tokens.
The efficiency of hashgraph consensus enables Hedera to be the most sustainable public network, based on average energy consumed per transaction (0.000003 kWh), according to a recent study conducted by University College London.In addition, Hedera has committed to being a carbon-negative public network through the purchase of quarterly carbon credits to offset the small amount of emissions from all public-facing infrastructure.
The UCL team used a mathematical consumption model that predicts expected energy consumption per transaction, as a function of network load. Applying this model to six different PoS-based DLT systems confirms that their energy consumption per transaction is indeed at least three orders of magnitude lower than that of Bitcoin. Furthermore, UCL discovered significant differences among the analyzed PoS-based systems themselves.
This chart illustrates an estimated current number of transactions per each of the listed protocols (based on recent throughput measures).
This chart illustrates an estimated maximum throughput of the protocols.
This chart illustrates an estimated energy consumption of the protocols considered under contemporary throughput (based on recent throughput measures).
Building a sustainable future