Proof-of-Work (PoW) is a consensus mechanism that requires miners to solve complex mathematical puzzles to validate transactions and add new blocks to the blockchain. This process is computationally intensive and consumes a significant amount of energy.

The primary concern regarding the sustainability of blockchain technology is its high energy consumption, particularly in networks that use the Proof-of-Work (PoW) consensus mechanism.

Proof-of-Stake (PoS) is a consensus mechanism that selects validators based on the amount of cryptocurrency they hold. This eliminates the need for energy-intensive mining, making it a more sustainable alternative to Proof-of-Work.

Consensus transition refers to the process of changing the consensus mechanism used by a blockchain network. This is often done to improve the network's sustainability, security, or scalability.

Ethereum successfully transitioned from Proof-of-Work to Proof-of-Stake in September 2022, significantly reducing its energy consumption.

The Bitcoin network's estimated energy consumption is approximately 100 terawatt-hours (TWh) per year, comparable to the annual electricity consumption of a small country.

Cardano is a blockchain platform that has been designed with a focus on sustainability and energy efficiency from its inception. It uses a Proof-of-Stake consensus mechanism and has implemented various energy-saving features.

Green blockchain refers to the practice of using renewable energy sources, such as solar and wind power, to power blockchain networks. This reduces the environmental impact of blockchain technology.

Ethereum has pledged to achieve carbon neutrality by 2030. The network is actively exploring various strategies to reduce its energy consumption and transition to renewable energy sources.

Staking is the process of verifying transactions on a blockchain network by holding a certain amount of cryptocurrency. This eliminates the need for energy-intensive mining and is a key feature of Proof-of-Stake consensus mechanisms.

Solana uses a unique consensus mechanism called Proof-of-History, which relies on a verifiable record of past events to achieve high transaction throughput and energy efficiency.

Supply chain transparency refers to the use of blockchain technology to track and verify the provenance of products and materials throughout the supply chain. This enhances transparency, traceability, and accountability.

IOTA is a blockchain platform that uses a unique consensus mechanism called Directed Acyclic Graph (DAG). This allows for high scalability and energy efficiency, making it suitable for applications in the Internet of Things (IoT) and machine-to-machine communication.

Blockchain voting refers to the use of blockchain technology to create a decentralized and transparent voting system. This enhances the security, integrity, and transparency of the voting process.

Zcash is a blockchain platform that uses a unique consensus mechanism called Zero-Knowledge Succinct Non-Interactive Argument of Knowledge (zk-SNARKs). This allows for enhanced privacy and scalability, making it suitable for applications that require anonymity and confidentiality.