By leveraging the unique properties of nanofluids, a new type of solar panel can achieve higher efficiencies than traditional solar collectors, helping to create a cleaner, more sustainable future
The dual challenges of climate change and dwindling fossil fuel reserves have intensified the search for sustainable energy solutions. Solar stands out as one of the most promising alternatives due to its abundance, renewability and minimal environmental impact, and now direct absorption solar collectors (DASCs) represent a cutting-edge advancement in solar technology, offering a promising path to harnessing the sun鈥檚 energy more efficiently than ever before.
A team of researchers at Khalifa University has comprehensively reviewed this new technology, shedding light on the fundamentals, modelling approaches, and design parameters of DASCs, highlighting their potential to revolutionize solar energy utilization.
Prof. Eiyad Abu-Nada, Dr. Anas Alazzam and Alabas Hasan, PhD candidate, published their research in, a top 1% journal. They say, to bridge the gap between theoretical research and commercialization, a comprehensive understanding of DASCs is essential and their review serves as an invaluable resource for researchers seeking a more nuanced understanding of this evolving field, facilitating its advancement into practical applications.
Traditional solar panels absorb sunlight onto a surface coated with highly absorptive materials. However, they suffer from significant heat losses, which limit their efficiency. Direct absorption solar collectors replace the conventional absorber surface with a nanofluid allowing for volumetric absorption of sunlight throughout the bulk nanofluid volume. This approach minimizes thermal losses and enhances the overall efficiency of solar energy conversion.
Nanofluids are engineered suspensions of nanoparticles, typically ranging from 1 to 100 nanometers, within a base fluid. These nanoparticles dramatically improve the optical and thermal properties of the fluid, enabling it to absorb more sunlight and convert it into heat more efficiently. One of the key advantages of nanofluids is their ability to harness the phenomenon of localized surface plasma resonance: When sunlight strikes metallic nanoparticles like gold or silver, it excites electron oscillations, significantly increasing radiative energy absorption. This translates to improved efficiency in converting solar energy into usable thermal energy.
The research team points out that several factors influence the performance of DASCs, including the type of nanofluid used, the concentration of nanoparticles, the geometry of the collector, and the flow properties of the fluid.
Beyond technical performance, economic feasibility is also a factor. Fortunately, the price of producing nanofluids has declined, making the technology more accessible. There are still several research challenges to address, however. Stability of the nanofluids over long periods remains a concern, as nanoparticles tend to aggregate, which can diminish efficiency. The research team says future research should focus on developing more stable nanofluids and exploring new materials that can further enhance solar absorption and thermal conductivity.
Jade Sterling
Science Writer
20 Aug 2024
