Single-tank thermocline thermal energy storage (TES) systems using molten salt offer significant cost advantages for concentrating solar power plants, but maintaining sharp thermal stratification remains challenging due to natural convection-induced mixing. This thesis investigates a novel thermocline TES configuration comprising a cylindrical tank filled with HITEC XL molten salt and an internal recirculation channel equipped with electrical heating resistors, representing a hybrid solar-electrical storage approach. The study employs computational fluid-dynamics (CFD) analysis using STAR-CCM+ to evaluate thermocline formation under natural and forced convection conditions. A multi-stage methodology is developed: first, a three-dimensional model characterizes the heating rod bundle across various operating conditions with pressure drop predictions and outlet temperatures values.