The objectives of this work carried out in the Central African Republic are to propose new correlations between the components of solar radiation and the sunshine duration on a horizontal surface on the ground, and then to make an evaluation of the solar potential in the cities of Bambari, Birao, and Bangui. Polynomial regression models were used and their parameters were estimated by the ordinary least-squares method. A statistical evaluation allowed us to compare the performance of the models. The best correlations are then used to estimate the global and diffuse radiation. In the city of Birao, the estimated global radiation is around 6 kW h/m2 j and the diffuse radiation is around 2 kW h/m2 j; in Bambari, the global radiation is around 5.4 kW h/m2 j and the diffuse is around 2.3 kW h/m2 j; in Bangui, the global radiation is around 5 kW h/m2 j and the diffuse radiation is around 2.3 kW h/m2 j. The potential solar in all these regions is very favorable for small- and large-scale solar photovoltaic applications.