Publications

Abstract : This chapter provides a brief background in the various conventional methods (surface-based absorption of solar energy) available for harnessing solar thermal energy at a community level. It describes some of the main differences between the typical non-concentrating as well as concentrating type solar collectors, and highlights some of their main attributes. It also presents in detail the results of a novel technique for harnessing solar energy. In this technique, the solar energy is directly absorbed by the fluid (volumetrically) using nanoparticle-laden fluids (hence, it is categorized as volumetric-based absorption of solar energy). Such a collector is analysed in detail using a numerical model. The results of the numerical model are then discussed, which simulates the requirements of hot water for a typical community consists of about 10 households (40 persons). Two of the main performance evaluation parameters - collector efficiency and the fluid outlet temperature - have been extensively studied, and the influence of various design and operational parameters (particle volume fraction, mass flow rate, solar irradiation, collector height, collector length) on these two have been studied in detail. Moreover, the variation of spectral intensity, energy generation rate and spatial temperature distribution within the collector has been quantified. The calculations also show the dimensions of the desired solar collector in order to meet the daily hot water requirements (100 kg/person) for this community.