The Taoist philosophy defines through the Ying and Yang duality, that has everything that exists in the universe, so that there are always two antagonistic and complementary forces that need each other. You can hardly appreciate the value of the Peace without the existence of wars or health if there were no diseases.
This dual approach is also applicable to technology, imposing conditions that often are opposite, but allow the balance of systems. According to the Thermodynamics, for the production of cold (heat extraction to a source of lower temperature) has to provide external power and dissipate heat to a medium that is hotter than the area you want to cool, so that the heat and cold coexist like the Ying and Yang were addressed.
The conditions of habitability that living beings we have, they require us to maintain a suitable temperature to carry out life processes, in such a way that values at 23 ° C environment, they allow us to be comfortable. However the weather and outdoor conditions present values sometimes far removed from this optimum: from – 40 ° C, which can be in areas close to the Poles, up to 55 ° C which can be summer in areas close to the Equator being essentially the presence or absence of solar radiation which causes these differences.
Technology has developed systems for the transformation of solar energy into heat or electricity, making it applicable to both heating and cooling. The absence of solar radiation produces the need for heating, and therefore it seems unlikely that we can take advantage of the available radiation that will generally be small for heating. However, the need to cold will be generally associated with the presence of sunlight, as if they were also of the Ying and Yang. In fact the air conditioning is one of them technologies star for the World Football Championship of Qatar in which is going to use fields of soccer refrigerated through energy solar (“Wolfgang Kessling: “How to air-condition outdoor spaces”).
The solar cooling offers a set of technologies in which the solar radiation is used to produce cold water with sorbents systems (absorption or adsorption machines) previously heated with solar panels or from electricity produced with photovoltaic solar energy to power a system based on compressor. As if they were the brothers of “Rich man, poor man”, their temporal evolution has been and is different.
Until makes some 10 years, were the systems of cold solar based in machines sorbent which had of a greater number of applications and developments technological. In those days the photovoltaic face was expensive. However, with the reduction of the cost that has suffered recently this last, the use of photovoltaic to produce cold solar is increasing of way important. On the other hand, there are manufacturers of machines of absorption with systems of triple effect and yields of the 180% willing to present a hard battle for the air conditioning with radiation solar.
In any case regardless of the technology that is winner, I have clear is that, the future of the cold is hot, as hot as the Sun.