en 5-Communication Systems Communication Systems Review Paper Review Paper <span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">Solar energy, a vital renewable resource, requires efficient trading mechanisms, typically managed through Power Purchase Agreements (PPAs). However, current trading networks face significant challenges, including inadequate transaction tracking, limited data accessibility, and low transparency and trust. Blockchain technology offers a promising solution to these issues. This paper provides a comprehensive review of blockchain applications across various trading domains. We begin by introducing fundamental blockchain concepts and their role in enhancing solar energy trading security and functionality. Subsequently, we investigate existing blockchain-based platforms and conclude with a specific case study on solar energy. This study proposes a blockchain-based peer-to-peer (P2P) trading system designed to optimize solar energy exchanges. A comparative analysis between the proposed TBP platform and Power Ledger reveals key<b> </b>distinctions in architecture, data management, and pricing. Notably, the TBP platform offers a more integrated framework and flexible pricing, highlighting the vast research potential in blockchain-enabled solar trading and PPA implementation.</span></span> blockchain, solar energy trading, smart contract, token, Power Purchase Agreement (PPA) 4076 4076 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-6031-2&slc_lang=en&sid=1 mehrzad mirzasadeghi mehrzada.mirzasadeghi@gmail.com 1800319475328460017937 1800319475328460017937 Yes Shahid Bahonar University hossein nezamabadi pour nezam@uk.ac.ir 1800319475328460017938 1800319475328460017938 No Shahid Bahonar Univesity