Solar cooling: PV or thermal? A thermodynamic and economical analysis

• Solar cooling is obtained with solar thermal or PV with easy available equipment.
• In the past PV driven systems for solar cooling were not considered as too expensive.
• The investment cost of some thermal and PV solar cooling systems are comparable.
• An energy/economic comparison is carried out for the various solar cooling systems.

Many technologies are available to produce solar cooling. The most widespread options are solar thermal driven sorption and photovoltaic driven compression chillers. Sorption chillers can be single or double effect LiBr–H2O water cooled or H2O–NH3 air cooled. The requested temperatures are respectively around 90 °C for the first engine and 160 °C for the other two. The solar section can be realised with flat plate or evacuated tube collectors at a fixed tilt or parabolic trough collectors with a tracking system. The possible solar cooling systems are evaluated during a sunny day and compared with the PV driven system first with respect to the overall system efficiency. Finally the comparison regards also the investment cost for the various systems.Whereas in the past the PV driven system was considered too expensive with respect to the solar thermal, now it is quite comparable above all if the systems are air cooled.