Browsing by Author "Karim, Mounia"

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    Impact of dust on electrical power output of solar PV modules in North-East, Nigeria
    (Niger State College of Education, 2022-05-30) Abdulkarim, Hauwa Talatu; Sansom, Christopher L.; Patchigolla, Kumar; Almond, Heather; Karim, Mounia
    The impact of dust on the solar PV modules deserves more attention. North-eastern Nigeria has high potential of solar irradiance but it is proned to dust accumulation. This paper therefore, investigated the impact of dust on the performance of solar Photovoltaic modules in North-Eastern Nigeria. The investigation entailed field experiment carried out in Maiduguri to assess the performance of the module based on continuous dust deposition for 14 days during dust accumulation period. The results show that more than 50% loss in power output was recorded under 14 days of continuous deposition. The efficiency of the module reduced from 17.1% on the first day to 7.2% on the fourteenth day of the experimentation. The investigation also shows that at high humidity the PV performance drops. Solar irradiance increases the performance. The deployment of solar PV energy supply system is recommended in spite of dust accumulation challenges. To maintain adequate performance of the system, a once a week cleaning is recommended during intense dust accumulation period.
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    Investigation of the Thermo-hydraulic performance of a roughened Parabolic trough collector
    (Elsevier, 2022-10-28) Allauddin, Usman; Rafique, Muhammad U.; Malik, Osama; Rashid, Osama; Waseem, Ashir; King, Peter; Karim, Mounia; Almond, Heather
    Parabolic trough collectors (PTC) are an already established technology set to prove its competitiveness. Recently, a lot of research is ongoing to further enhance the thermal performance of PTC systems. Computational Fluid Dynamics (CFD) can help in the design and development of PTCs with optimized thermal efficiency. In the current work, a combined enhancement in the performance of a PTC is evaluated, involving modifications to the geometry of the absorber tube and the use of a heat transfer fluid (HTF) (Syltherm800). Absorber tube geometries involving dimpled protrusions (d-PTC) and circumferential inclined ribs (IR-PTC) are used. The performance of PTC with and without turbulators is compared with that of a smooth absorber tube by calculating the Nusselt number (Nu), friction factor (f) and performance evaluation criterion (PEC). PEC values of 1.46 and 1.18 are observed by using inclined ribs and dimpled protrusions, respectively at an absorber tube inlet temperature (Tin) of 500 K and mass flow rate (m) of 0.5 kg s−1. Thus, a significant enhancement in thermo-hydraulic performance of PTC is observed with inclined rib turbulators.
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    Variability and associated uncertainty in image analysis for soiling characterization in solar energy systems
    (Elsevier, 2023-07-04) Smestad, Greg P.; Anderson, Cody; Cholette, Michael E.; Fuke, Pavan; Hachicha, Ahmed Amine; Kottantharayil, Anil; Ilse, Klemens; Karim, Mounia; Khan, Muhammad Zahid; Merkle, Herbert; Miller, David C.; Newkirk, Jimmy M.; Picotti, Giovanni; Wiesinger, Florian; Willers, Guido; Micheli, Leonardo
    The accumulation of soiling on photovoltaic modules and on the mirrors of concentrating solar power systems causes non-negligible energy losses with economic consequences. These challenges can be mitigated, or even prevented, through appropriate actions if the magnitude of soiling is known. Particle counting analysis is a common procedure to characterize soiling, as it can be easily performed on micrographs of glass coupons or solar devices that have been exposed to the environment. Particle counting does not, however, yield invariant results across institutions. The particle size distribution analysis is affected by the operator of the image analysis software and the methodology utilized. The results of a round-robin study are presented in this work to explore and elucidate the uncertainty related to particle counting and its effect on the characterization of the soiling of glass surfaces used in solar energy conversion systems. An international group of soiling experts analysed the same 8 micrographs using the same open-source ImageJ software package. The variation in the particle analyses results were investigated to identify specimen characteristics with the lowest coefficient of variation (CV) and the least uncertainty among the various operators. The mean particle diameter showed the lowest CV among the investigated characteristics, whereas the number of particles exhibited the largest CV. Additional parameters, such as the fractional area coverage by particles and parameters related to the distribution's shape yielded intermediate CV values. These results can provide insights on the magnitude inter-lab variability and uncertainty for optical and microscope-based soiling monitoring and characterization.