Nigeria has embarked on various programmes and policies in trying to make its energy system efficient. Renewable energy (RE) is one at the heart of this reformation. However, the country's energy reforms within the ambit of RE suffer setbacks, owing to poorly utilized RE resources and initiation of relevant policies. Consequently, these setbacks widen the gap between energy demand and supply. This has motivated the need to appraise the effectiveness, efficiency, equity and institutional feasibility of Nigeria's RE legal and policy framework. The study adds to literature by adopting a case study approach to initiate improvement of the effectiveness and efficiency of the Nigerian RE legal and policy framework. Our results disclose an urgent need to drive a coordinated and consistent legal intervention, specific and time-bound targets, political commitment, policy choice and design, funded research and development activities, social awareness and public engagement, in order to improve RE development and deployment in Nigeria. Additionally, enacting well-conceived RE laws in Nigeria and building relevant institutions, were identified to be crucial in achieving expansive and sustainable RE development for the country.