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.

Chapter Contents:

• Abstract
• 5.1 Introduction
• 5.2 Solar energy
• 5.3 Flat-plate collector
• 5.3.1 Construction and operation of a flat-plate collector
• 5.3.2 Design and operational parameters
• 5.4 Community-level volumetric absorption-based solar collectors (using nanofluids)
• 5.4.1 Numerical model of the volumetric absorption-based solar collector
• 5.4.2 Parameters influencing the performance of the solar collector
• 5.5 Summary
• References

Inspec keywords: absorption; temperature distribution; solar energy concentrators; solar power; nanoparticles; solar absorber-convertors; numerical analysis

Other keywords: spectral intensity; numerical model; community-level solar thermal systems; concentrating type solar collectors; spatial temperature distribution; surface-based absorption; community level; solar thermal energy; nanoparticle-laden fluids; hot water; fluid outlet temperature; collector efficiency; performance evaluation parameters; energy generation rate

Subjects: Photothermal conversion; Solar collectors, concentrators and control films: optical aspects; Numerical approximation and analysis; Solar energy