Of course, the main motive for introducing reactive power compensation is energy saving. It is not difficult to calculate future savings if the power factor and some parameters of the mains are known. However, in addition to a direct reduction in the consumed active power and the corresponding electricity charge, the use of capacitor units is accompanied by a number of additional effects. In some cases, their value can be comparable, and sometimes exceed the direct benefit of energy savings, therefore, when deciding on the implementation of PFC systems should comprehensively analyze the situation at the facility. The proposed article will help to draw attention to some important aspects of such an analysis.