An energy efficient power supply system is disclosed. The energy efficient power supply system comprises a plurality of power supply units and the power supply system may be coupled to the control logic. The control logic may be coupled to the power monitor unit. The power monitor unit may determine a power consumption value, which may represent power requirement of a power consuming system such as a computer system. The control logic may determine the power supply units of the plurality of power supply units that are to be activated to provide power to match the power requirement. The control logic may identify the power supply units that may be activated to operate at a maximum efficiency value while providing power specified by the power consumption value.