Energy Savings : The energy savings achieved by voltage optimisation are an aggregation of the improved efficiency of all equipment across a site in response to the improvements in the power quality problems outlined above. It has been and continues to be a key technique for savings in energy consumption. Research in Taiwan suggested that, for an industrial supply, for voltage reduction upstream of the transformer, there is a 0.241% decrease of energy consumption when the voltage is decreased by 1%, and an increase of 0.297% when the voltage is increased by 1%. This assumed a mixture of loads including 7% fluorescent lighting, 0.5% incandescent lighting, 12.5% three phase air conditioners, 5% motors, 22.5% small 3-phase motors, 52.5% large 3-phase motors.
for more details