This paper investigates new optimization technique to size the capacitor banks to improve the power factor in the low voltage distribution networks. In industrial sites the owner should take decision either to pay the penalty due to low power factor or buy capacitor bank's panels. Economical study should be performed to take this decision. Choosing the size of the reactive power of the capacitor bank is the key player to perform the economic study, JAYA technique is new optimization method based on heuristic research, this method is implemented in this research to choose the optimal size of the implemented capacitor banks. The output of the optimization technique is accordingly fed to the capacitor bank controller to engage the suitable capacitor units for each loading condition. MATLAB/M-files program is used program the JAYA objective cost function and the power factor correction equations. The proposed program gives a good results where it give minimum cost of capacitor banks that met higher power factor.