@article{Otanicar2010-uh,
  author = {Todd P Otanicar and Patrick E Phelan and Ravi S Prasher and others others},
  title = {Nanofluid-based direct absorption solar collector},
  abstract = {<p>Solar energy<span>\&nbsp;is one of the best sources of renewable energy with minimal environmental impact. Direct\&nbsp;</span>absorption<span>\&nbsp;</span>solar collectors<span>\&nbsp;have been proposed for a variety of applications such as water heating; however the efficiency of these collectors is limited by the\&nbsp;</span>absorptionproperties<span>\&nbsp;of the working fluid, which is very poor for typical fluids used in\&nbsp;</span>solar collectors.<span>It has been shown that mixing\&nbsp;</span>nanoparticles<span>\&nbsp;in a liquid (nanofluid) has a dramatic effect on the liquid thermophysical\&nbsp;</span>properties<span>\&nbsp;such as\&nbsp;</span>thermal conductivity.<span>\&nbsp;</span>Nanoparticles<span>\&nbsp;also offer the potential of improving the radiative\&nbsp;</span>properties<span>\&nbsp;of liquids, leading to an increase in the efficiency of direct\&nbsp;</span>absorption<span>\&nbsp;</span>solar collectors.<span>\&nbsp;Here we report on the experimental results on\&nbsp;</span>solar collectors<span>\&nbsp;based on nanofluids made from a variety of\&nbsp;</span>nanoparticles<span>\&nbsp;(carbon nanotubes, graphite, and\&nbsp;</span>silver).<span>\&nbsp;We demonstrate efficiency improvements of up to 5\% in solar thermal collectors by utilizing nanofluids as the\&nbsp;</span>absorption<span>\&nbsp;mechanism. In addition the experimental data were compared with a numerical\&nbsp;</span>model<span>\&nbsp;of a\&nbsp;</span>solar collector<span>\&nbsp;with direct\&nbsp;</span>absorption<span>\&nbsp;nanofluids. The experimental and numerical results demonstrate an initial rapid increase in efficiency with volume fraction, followed by a leveling off in efficiency as volume fraction continues to increase.</span></p>},
  year = {2010},
  booktitle = {J. Renewable Sustainable Energy},
  journal = {J. Renewable Sustainable Energy},
  series = {J. Renewable Sustainable Energy},
  month = {05/2010},
  institution = {aip.scitation.org},
  publisher = {aip.scitation.org},
  doi = {10.1063/1.3429737},
  language = {eng},
}