Abstract

Blockchain technology enables decentralized, secure, and transparent transactions but faces criticism for the high energy consumption of traditional consensus mechanisms like Proof of Work (PoW). Addressing these concerns, “Green Blockchain” focuses on energy-efficient mechanisms to reduce ecological impact while maintaining decentralization, transparency, and security. This chapter explores sustainable consensus methods, including Proof of Stake (PoS), Delegated Proof of Stake (DPoS), and Proof of Authority (PoA), alongside emerging algorithms emphasizing energy efficiency. It analyzes their architecture, benefits, and trade-offs, with case studies in IoT, supply chain management, and digital identity. Additionally, it examines challenges in scalability, security, and global adoption, offering insights into blockchain's sustainable future.