System used

Efficiency (%)-primary energy use to cooling energy

Solar-PV combined with compression chiller

22.1

Solar thermal-flat plate collectors combined with Adsorption chiller

22.5

Solar thermal-evacuated tubes combined with Absorption chiller

48

Solar thermal-parabolic troughs combined with Absorption chiller

56

Heat pumps using grid electricity1,2

105

Compression chillers using grid electricity1

45