The Sustainable Development Goal (SDG7) aims to ensure access to affordable, reliable, sustainable and modern energy for all by in Tanzania, a country with significant energy challenges. A comprehensive literature review and qualitative analysis of existing policies and case studies will be conducted. Decentralized systems present an effective theoretical approach for achieving SDG7 in Tanzania by offering tailored energy solutions that enhance access and reliability while considering economic viability. Policy makers should prioritise supportive regulatory environments, financial incentives, and community engagement strategies to facilitate mini-grid development and widespread adoption. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.