The literature on multi-attribute optimization for renewable energy source (RES) placement in deregulated power markets is extensive and diverse in methodology. This study focuses on the most relevant publications directly addressing the research problem at hand. Similarly, while the body of work on optimal location and sizing of renewable energy generators (REGs) in balanced distribution systems is substantial, only the most pertinent sources are cited, aligning closely with the study’s objective function. A comprehensive literature review reveals several key research areas: RES integration, RES-related optimization techniques, strategic placement of wind and solar generation, and RES promotion in deregulated power markets, particularly within transmission systems. Furthermore, the optimal location and sizing of REGs in both balanced and unbalanced distribution systems have been extensively studied. RESs demonstrate significant potential for standalone applications in remote areas lacking conventional transmission and distribution infrastructure. Also presents a thorough review of current modeling and optimization approaches for RES-based distribution system location and sizing. Additionally, it examines the optimal positioning, sizing, and performance of hybrid and standalone renewable energy systems. This paper provides a comprehensive review of current modeling and optimization approaches for the location and sizing of Renewable Energy Sources (RESs) in distribution systems, focusing on both balanced and unbalanced networks.