Decentralized Renewable Energy Marketplaces (DREMs) are utilizingthe blockchain technology to facilitate peer-to-peer energy transactions.Although this increases efficiency and transparency, it exposes thesystem to risks like Sybil attacks, in which attackers create fictitiousidentities with the goal of influencing market forces. To address suchsecurity and privacy concerns, in this thesis, we conduct a systematicliterature review to identify key vulnerabilities in DREMs, e.g., inadequate identity verification and pseudo-anonymity. We also identifypreventive measures, e.g., reputation-enhanced PBFT, which are associated with the corresponding weaknesses. Based on our findings,we propose a theoretical framework that utilizes state-of-the-art technologies, including Self-Sovereign Identities (SSIs), Digital MachineIdentifiers (DMIs), and Zero Knowledge Proofs (ZKPs) in a consortium blockchain. In the framework, ZKPs enable privacy-preservingtransactions, DMIs are used to verify devices, and SSIs are used tocreate unique identities for new prosumers. SSIs, DMIs, and ZKPscollectively provide a secure and tested mechanism of Sybil attackresistance while maintaining decentralization and efficiency.