????about saving energy....

Hi everybody

I have a question about a solar-assisted cooling system ,used to cool milk

The systeme basic components are electric compressors and an absorption machine,

When optimizing the compressor cycle, by lowering the temperature in the condensor, an important saving of energy can be made...........this lowering is the result of introducing the absorption machie ............;

my question is:

how does the lowering of temperature in the condensor influence the electric energy consumption?

i mean how could it be calculated?

for instance, if the compressor cools a volume of water at 7°C (instead of 9°C) to bring it to 2°C (knowing its capacity (2500kw) efficiency R and perhaps other characteristics) ,what would be the saved energy?

i really really need a help

i hope i will find it