Solar thermal systems convert solar energy into low temperature heat (approximately 60° to 90° C), obtained by heating a liquid flowing in small tubes housed in solar panels.
This technique is mainly used to produce hot water for domestic use, for ambient heating and for cold production by means of absorption refrigeration machines (solar cooling) or heat for an industrial process.
RSE activities in this area have focused on the use of solar cooling technologies and in particular on energy performance analysis of actual plants identified in Italy. These plants use solar heat, supplemented by other sources, for summer cooling, winter heating and, in one case, also for the production of sanitary hot water, however, which is of less importance.
Three plants were monitored, two equipped with an absorption refrigeration system and one with a DEC system (Desiccant Evaporative Cooling). RSE has installed specific equipment to capture and store data on the functioning of these plants to detect the weather conditions and solar radiation on the ground.
The results obtained have made it possible to evaluate, as a first hypothesis, that the DEC system, which involves the use of pure water for cooling, is an energetically interesting solution for solar conditioning; vice versa the solution that involves the use of absorption refrigerator seems to be the least favorable for the exploitation of solar radiation.