The zener diode shunt is very economic as it is of low cost.
It requires only two or three components.
It has a very simple circuit.
It provides a better regulation over a wider range of load currents and input voltages.
It provide higher current capability.
There are some disadvantages of zener diode shunt regulator are given below,
It has poor efficiency for heavy loads because a considerable amount of power is wasted in zener resistance (R2) and series resistor (RS) in comparison with load power.
The DC output voltage slightly changes due to zener resistance.
Changes in load current produce changes in zener current.