DC microgrids are currently experiencing a surge in attention and interest, emerging as a focal point in the global energy discourse due to their potential to enhance energy efficiency and seamlessly integrate renewable sources, including solar photovoltaic (PV). However, when large amounts of renewable energy sources are integrated, DC microgrids face difficulties with voltage regulation, energy management, inertia control, and uncertainty management. To address these difficulties, numerous approaches have been offered, such as droop control, centralized control, distributed control, virtual inertia control, and uncertainty management algorithms. Despite these efforts, a comprehensive overview that offers a panoramic understanding of the existing techniques and forthcoming trends in controlling renewable energy-integrated DC microgrids has been lacking. Thus, this article systematically reviews the challenges and opportunities arising from integrating renewable energy into DC microgrids. A comprehensive understanding of the challenges and potentials of renewable energy integration within DC microgrid systems is offered, thereby enriching the scholarly discourse in this field. The article provides a comprehensive evaluation of the inherent advantages and disadvantages of the existing methodologies while identifying specific areas that require additional investigation. The novelty of this work lies in its comprehensive review of challenges and opportunities in integrating renewable energy into DC microgrids, offering specific recommendations to enhance integration, and guiding future research in the field. Scholars, researchers, and professionals in related fields may all benefit greatly from this article.