The VARS uses heat energy, instead of mechanical energy as in VCRS, in order to change the refrigerant condition required for operation of the cycle.
In VARS, the compressor of VCRS is replaced by an absorber, a pump, a generator, and a pressure reducing valve. The COP of VARS is very low compared to VCRS.
In VARS ammonia or water is used as refrigerant which is cheaper compared to VCRS wherein halocarbons are used as refrigerants which are expensive.
The amount of power required by VCRS is in large quantities because of the compressor use, compared to VARS in which pump requires lesser amount of power.