Thermal performance enhancement of solar collectors by surface geometric modifications on the heated surface, use of solar selective coatings and nano-fluids

Abstract: Rapid depletion of fossil fuels which is our conventional source of energy and the degradation of environment have led to exploration of renewable energy sources. Solar energy is one of the most mature renewable sources of energy which provides thermal energy without any cost. Since last decade technologies used to harness solar energy have evolved as they are freely available and have commercial potential. This paper presents the advancement made in the field of solar thermal technology with emphasis on techniques employed for its thermal performance enhancement which includes geometric modifications on the heated surface of the solar collector to modify the boundary layer, use of nano-fluids to increase the thermal conductivity of the heat transfer fluid and use of solar selective coatings on the absorber surface to maximise the capturing of solar radiation.

Keywords: Heat transfer enhancement, nano-fluids, solar selective coating, solar collector, thermal performance.