The use of solar energy for everyday electricity and heat needs has distinct advantages: we avoid consuming resources and degrading the environment through polluting emissions, oil spills, and toxic byproducts. There is, however, one disadvantage to solar energy: the sun does not always shine. We need a way to store solar energy for times when the sun is not shining. Among the ways to safe solar thermal energy is the application of solar ponds with salinity gradient and heat pumps. However, in the countries with hot climate often the cooling of air/water is required. This problem also may be solved by means of solar energy, namely, by solar assisted heat pumps. There are various types of heat pumps working on the principle of thermodynamic phase transitions: evaporation-condensation, melting-crystallization, absorption-desorption. The chemical heat pumps are working by using the heat generated or consumed in the process of phase transition.
The solar cooler proposed by EcoAtom is based on the closed cycle where working medium is the proprietary inorganic metal salt hydrate having high heat of water evaporation. The receiver of solar radiation consists of heat insulated solar collector filled by mentioned salt. During charging time the solar energy absorbed in collector initiate water evaporation-desorption from the salt. The high pressure water vapor passing through heat-exchanger is condensed and water is collected in special receiver and evaporator. When solar collector is recharged the pressure in system declines and water evaporates reducing temperature of surrounding medium (freezing of special eutectic salt with high heat of melting in refrigerator). At the same time water vapor enters again in solar collector and is absorbed in salt. Thus, air or water can be cooled passing through heat-exchanger connected with refrigerator.