A group of final-year Mechanical Engineering students of the Sree Chithra Tirunal College of Engineering (SCTCE), Pappanamcode, have developed a prototype of a refrigeration system using direct sunlight, without converting it into electricity using solar panels. According to the students, the system, which was developed as part of their final-year project, does not use a solar panel; instead, it uses a parabolic-shaped solar concentrator made of stainless steel to concentrate the heat. “This method is much cheaper compared to a solar panel. In a conventional system, a compressor driven by electricity is used to pump the refrigerant, and a solar panel converts solar energy into electrical energy. This drives a compressor that has lesser efficiency owing to loss of power during conversion. To overcome the maximum possible heat loss, we integrated a component called heat pipe that provides effective heat transfer from the parabolic concentrator. Another component, known as adsorbent bed, receives the heat from heat pipe. The carbon inside the bed absorbs the refrigerant (methanol) when it is at low temperature and releases it at high temperature. This pressure is used to run the system,” K. Krishna Raj, one of the members of the team, says. The students said that the results of the experiment showed that its cooling efficiency was the same as any normal refrigerator. The other members in the team were M. Sankarlal, K. Naseer, and S.L. Shisin. Baiju V., Assistant Professor in Mechanical Engineering at the college, was the project guide. (Source: The Hindu, May 19, 2015)