A power consumption control apparatus and method, the power consumption control method including calculating a charging cost, which represents a cost of power in a case of charging power, and a discharging cost, which represents a cost of power in a case of discharging power, of a power storage unit where the charging and discharging of power is performed, comparing the charging cost with the discharging cost of the power storage unit, controlling a power conversion unit to perform a discharging mode of performing one of the discharging of power and a reselling of power if the discharging cost is lower than the charging cost, and controlling the power conversion unit to perform a charging mode of charging the power storage unit with at least one of a new renewable power and a grid power if the charging cost is equal to or lower than the discharging cost.