May 10 2010
Although solar energy has already been utilized for powering air-conditioning systems, researchers are taking steps to utilize sunlight’s energy to refrigerate fruits and other foods. To this end, scientists of the Fraunhofer Institute for Solar Energy Systems ISE located in Freiburg indicate that this is a feasible solution in the region of the Mediterranean by utilizing real examples of a Moroccan dairy and a Tunisian winery.
In the MEDiterranean food and agro Industry applications of Solar COoling technologies (MEDISCO) project, the collaboration of European companies, energy agencies and universities have resulted in the installation of solar plants meant for refrigerating wine and milk. Operated by the Polytechnic University of Milan, this project received funding from the European Commission.
ISE scientist Tomas Núñez stated that this approach is ideal for nations having abundant sunlight and also in remote regions lacking sufficient water supply and not having reliable energy resources. The approach decreases electricity usage for conventional refrigerators and is environmentally friendly.
By installing concentrating collectors that focus the sunlight to an absorber through a reflector, enables the conversion of sunlight into water having 200 degrees temperature. This high water temperature is needed to run the absorption refrigeration machine. Rather than using electricity, the scientists use heat to offer the refrigeration. A mixture of water-glycol is used for the refrigeration process. The scientists utilize the water-glycol mixture for preventing the freezing of water, even as the absorption refrigeration machine generates zero degree temperature. This water-glycol mixture is collected and sent via a heat exchanger for cooling the milk.
Source: http://www.fraunhofer.de/