As paradoxical as it might sound, cooling with solar energy is feasible. Thus cooling with solar thermal is an obvious driving force and main reason for the demand.

"Conventional" compression cooling systems just like heat driven cooling machines use the same physical principle. When a substance evaporates it removes energy from the surface it's been on, thus cools it.

In a thermal cooling cycle evaporation is driven by the tendency of the substance, the so called refrigerant, to dissolve in/on a sorbent.

But when concentration is too high, the sorbent has to be regenerated, by driving out the refrigerant with heat, e.g. with solar thermal.

The trend to architecture with greater glass surfaces and growing comfort demand made the energy consumption for air-conditioning increase dramatically in the last years. In some country this has already led to an electrical grid overload and break down. This dread and the need to reduce green house gases for electricity production make the introduction of cooling with renewable energy sources indispensable.

In the end of last century it was still common view that solar cooling would only be profitable through photovoltaic driven compression cooling machines.

But optimized collectors, the improvement of other components and an enhanced system design made solar thermal cooling mature to a real technical alternative. It is now even on the edge to financially compete with systems operating with conventional electricity sources.