Remarks and Future Scope
Rising global population and living standards concerns over climate change, secure and safe low carbon
energy supplies. Over the next 40 years, in order to sustain life and standards of living to which have
grown accustomed, we must develop deep solutions for massivity scaling terawatts of affordable
sustainable energy and develop means to reduce on CO2 emissions. A pivotal future research should be
determining the energy transport mechanism and green energy (solar thermal) in nanofluids. The solar
thermal based engineering as well as many other industries has specific needs to increase heat transfer
rates under a variety of constraints. Nanofluids have to satisfy many such needs and constraints. For solar
thermal applications, the important features of nanofluids are the high transfer coefficients for liquids
with high boiling points and medium pressures. Increased heat transfer rates in solar collectors could
reduce the pumping power needs. However, ideal or even optimized nanofluids for solar thermal
applications do not exist yet. The above review shows that the application of nanofluids in solar energy
applications is still in its early stages so far, theoretical investigations have been reported on parabolic
trough collectors; subsequently experimental studies can be performed. Practical implications of
nanofluids are influenced by major factors such as production cost, synthesis methods, physical &
chemical parameters. The evolvement of nanotechnology in future may overcome these factors.
This paper presents overview about nanofluid with solar collector applications, an existing emerging class
of heat transfer fluid, in terms of barriers, future research and environmental challenges. Nanofluids are
used to increase the performance of many thermal engineering systems. The use of nanofluids in the solar
collectors may raise the effectiveness of the collectors using both experimental and theoretical
investigations subjected to certain limitations. Experimental works encountered the major limitations,
such as particle agglomeration, stability, erosion and corrosion of the heat transfer equipment’s.
Numerical simulations requires more exact models such as two phase mixture models need to be done for
various solar collector applications. Based on the recent investigations, it was observed that the volume
fraction and particle size plays a major role in determining the effectiveness [48]. Further the nanofluids
concentration by weight percentage [48,53], volume percentage [48,50] and also pH [49] plays a vital role
in the performance of the solar collector. Future studies are exposed widely on the application of
nanofluids for high temperature applications and energy storage devices by having experimental and
theoretical investigations. The nanofluids for any real applications can be made viable practically by
undergoing study under different environment, geographical conditions testing its viscosity, fluid
properties and thermo-physical properties on different thermal applications. Researchers on using the
nanofluids on solar collector applications are at its fundamental level. Using the solar fuel with
nanotechnologies in solar collector application have enormous potential in the future and is under global
focus to attain clean and green energy.