Advantage:

1) TRIAC can be triggered with positive or negative polarity voltages.

2) A TRIAC needs a single heat sink of slightly larger size, whereas anti- parallel thyristor pair needs two heat sinks of slightly smaller sizes, but due to the clearance total space required is more for thyristors.

3) A TRIAC needs a single fuse for protection. which also simplif‌ies construction.

4) In some d.c. applications, SCR is required to be connected with a parallel diode to protect against reverse voltage, whereas TRIAC used may work without a diode, as safe breakdown in either direction is possible.

Disadvantages

1) TRIAC have low $d_v/d_t$ rating compared to SCRs.

2) SCRs are available in larger rating compared to TRIACs.

3) Since a TRIAC can be triggered in either direction, a trigger circuit with TRIAC needs careful consideration.

4) Reliability of TRIAC is less than that of SCRs.