Despite its vast natural resources, African is facing serious challenges in sustainable development in an energy sector, if addressed with dispatch could not only check its indispensable needs but also mitigate some global phenomenon at stake, such as desertification, environmental degradation, and greenhouse emission. This paper reviews the prospects of four major renewable energy sources-hydro, solar, wind and biomass- for each of the two leading countries in Africa namely South Africa and Nigeria. Based on a literature survey of energy efficiency, all two countries encourage energy efficiency in varying degrees. In the course of this review, several national energy policy frameworks of these countries were looked into, especially on how African countries could overcome the persistent energy crisis in the continent by utilizing the naturally gifted renewable energy sources. This could only be achieved if proper technology, awareness, and skills for harnessing the resources are provided. Also, lingering energy challenges such as energy efficiency measures, needs for grid extension, energy storage technology, and seasonal variation were carefully highlighted.