Evaluation of artificial neural networks with satellite data inputs for daily, monthly, and yearly solar irradiation prediction for Pakistan

Solar irradiation is the most critical parameter to consider when designing solar energy systems. The high cost and difficulty of measuring solar irradiation makes it impractical in every location. This study’s primary objective was to develop an artificial neural network (ANN) model for global horizontal irradiation (GHI) prediction using satellite data inputs. Three types of ANN, namely, the feed forward neural network (FFNN), cascaded forward neural network (CFNN), and Elman neural network (EMNN), were tested. The findings revealed that altitude, relative humidity, and satellite GHI are the most effective parameters, as they are present in all the best-performing models. The best model for daily GHI prediction was FFNN, which decreased daily MAPE, RMSE, and MBE by 25.4%, 0.11 kWh/m2/d, and 0.01 kWh/m2/d. The FFNN daily MAPE, RMSE, and MBE values were 7.83%, 0.49 kWh/m2/d, and 0.01 kWh/m2/d. The EMNN performed best for monthly and annual prediction, reducing monthly MAPE, RMSE, and MBE by 50.62%, 0.13 kWh/m2/d, and 0.13 kWh/m2/d, while the reduction for yearly was 91.6%, 0.11 kWh/m2/d, 0.2 kWh/m2/d. The EMNN monthly MAPE, RMSE, and MBE values were 3.36%, 0.16 kWh/m2/d, and 0.16 kWh/m2/d, while the yearly values were 0.47%, 0.18 kWh/m2/d, and 0.004 kWh/m2/d

The effect of a reversed circular jet impingement on a bifacial module PVT collector energy performance

Photovoltaic thermal (PVT) technologies have a significant downside in addition to their numerous advantages. PVT technologies are constrained by the fact that its photovoltaic module gains heat due to exposure to solar irradiance, which reduces the photovoltaic efficiency. Jet impingement is one of the most effective methods to cool a photovoltaic module. An indoor experiment using a solar simulator was conducted on a bifacial PVT solar collector cooled by a reversed circular flow jet impingement (RCFJI) to evaluate the energy performance of the PVT collector. The study was conducted under a constant solar irradiance of 900W/m2 and flowrate (mass) ranging from 0.01 to 0.14 kg/s. Three bifacial modules with 0.22, 0.33, and 0.66 packing factors were mounted 25 mm above the RCFJI for cooling. The 0.66 packing factor module recorded the highest photovoltaic efficiency of 10.91 % at 0.14 kg/s flowrate (mass). Meanwhile, the 0.22 and 0.33 packing factors recorded a photovoltaic efficiency of 4.50 % and 6.45 %, respectively. The highest thermal efficiency recorded under the same operating condition was 61.43 %, using a 0.66 packing factor. Overall, the highest combined photovoltaic thermal (PVT) efficiency for 0.22, 0.33, and 0.66 was 56.62 %, 61.88 %, and 72.35 %, respectively

Correlation of Near-Infrared (Nir) Spectroscopy with Water Quality Sensors to Detect Concentration of Saccharomyces Boulardii in Water

Terahertz (THz) sensing of high sensitivity detection has given the possibility of a non-invasive method for measuring and monitoring microorganism from water resources. The purpose of this study is to analyse the effectiveness of Near-infrared (NIR) spectroscopy as a non-destructive and in-situ measurement-based method for detection of Saccharomyces boulardii (S. boulardii) in water. Samplings are prepared in biotechnology lab in Universiti Malaysia Pahang (UMP), a yeast species of S. boulardii is used as a model microorganism. A single colony of yeast was inoculated in liquid broth media and incubated for overnight culture. A standard serial dilution method was applied to prepare five samples at different yeast concentration in corresponding test tubes of 0%, 10%, 20%, 50% and 100%. A hand-held NIR spectroscopy with range from 900nm to 1700nm wavelength is deployed gapless to scan those test tubes through its optical window. Meanwhile another sample with similar concentrations are inoculated into volume 0.0071 m3 of water equipped with water quality sensor system for monitoring and analysis purpose. The findings show inoculation certain concentration of 10%, 20%, 50% and 100% of S. boulardii into the water generated certain level of NIR spectroscopy’s spectral absorbance of 0.723, 0.64, 0.357 and 0.121 correspondingly at 1067 nm wavelength. This proves NIR spectroscopy is a highly-sensitivity THz sensor at 1067 nm wavelength as absorbance is at the minimum level as S. boulardii concentration is at the maximum. This finding is further validated by Dissolved Oxygen (DO) sensor which demonstrates rising maximum of 8 ppm after an hour of S. boulardii’s inoculation compared to 4 ppm in a normal water. However, the DO level back to normal after 5 hours due to the acclimatization process of the yeast and demonstrate capability of DO sensor to detect presence of yeast in water. PCA and PLS analysis based NIR spectroscopy’s spectral absorbance also demonstrates ability to categorise severity of a microbial illness depending on its concentration. The results from this study has suggested that the NIR spectroscopy sensor as an excellent option for microbial sensing in water

Classification of Jet Impingement Solar Collectors – A Recent Development in Solar Energy Technology

Jet impingement mechanism has been extensively studied in previous research due to its ability to enhance the efficiency of a solar collector. The photovoltaic module temperature can be effectively lowered while preserving the temperature uniformity and enhancing the solar collector performance. Since jet impingement offers such a broad application, numerous studies have focused on its heat transfer characteristic. This article provides a comprehensive review of recent jet impingement solar collectors. Additionally, the design and performance of the jet impingement cooling methods on solar air collectors, photovoltaic and photovoltaic thermal systems are discussed. The comprehensive review is classified into four main components involving jet impingement in solar collector applications: single pass, double pass, concentrated and jet configuration. A critical review is discussed at the end of each classification. The nozzle streamwise and spanwise pitch, nozzle to target spacing, nozzle diameter, nozzle shape, and Reynold number significantly impact the heat transfer properties of jet impingement. Research on applying single pass-single ducts using jet impingement is still lacking and needs further research. Thermally, a double passsolar collector outperforms a single pass-solar collector due to the absorber plate's high heat extraction rate and more significant interaction caused by the doubled heat transfer surface

Heat Transfer Performance of a Novel Circular Flow Jet Impingement Bifacial Photovoltaic Thermal PVT Solar Collector

Jet impingement is commonly used to enhance the performance of solar collectors by improving the heat transfer rate. This paper presents a Novel Circular Flow Jet Impingement applied to a bifacial photovoltaic thermal (PVT) solar collector. The energy performance of the PVT solar collector was analyzed using CFD COMSOL simulation. The circular flow cup was attached to the jet plate with 36 jet plate holes and streamwise pitch, X = 113.4mm, and spanwise pitch, Y= 126mm. The inlet circular cup diameter of 6mm and outlet jet plate hole of 3mm are used to promote impinging jet effects on the photovoltaic module. The mass flow rate ranges between 0.01-0.14kg/s, and Reynolds number ranges between 2,738-14,170 to promote turbulent flow. The swirling and diffusive properties of turbulence enhance the heat transfer rate. The study was conducted to analyze two distinct scenarios: the first sought to identify the optimal diameter size, and the second sought to determine the optimal depth for the circular cup. Each model was tested with a solar irradiance ranging from 600W/m2 to 900W/m2 . The optimum design for the Circular Flow Jet Impingement was achieved using a 40mm diameter and 20mm depth with a maximum photovoltaic, thermal, and overall efficiency of 63%, 11.09% and 74.09% at an irradiance of 900W/m2 and flow rate of 0.14kg/s

Performance enhancement of photovoltaic modules with passive cooling multidirectional tapered fin heat sinks (MTFHS)

The electrical output of photovoltaic (PV) modules degrades with continued exposure to extreme temperatures caused by solar radiation. The uniqueness of this research lies in the utilization of multidirectional fins with varying heights, which effectively accelerate heat transfer in PV cooling systems by inducing a transition in the boundary layer within the confined zone of the fins. The research aims to investigate the effect of using Multidirectional Tapered Fin Heat Sinks (MTFHS) to improve the efficiency of PV modules by utilizing aluminum alloy material as heatsinks. The proposed multidirectional design aims to facilitate enhanced heat transfer by promoting airflow in the central area of the PV module. The experimental procedures in our study differ from previous research as we utilized the latest generation of PV modules (405 Wp, PERC Half-cut cells) to fill the discrepancy between laboratory-based investigations and practical applications. Two PV modules were tested for an outdoor parametric analysis under outdoor operating conditions, with solar irradiance recorded from 200 to 1000 W/m2 and ambient temperatures ranging from 26° to 38 °C. Findings indicated that the proposed MTFHS could lower PV module temperatures by 12 ⁰C. Reduced temperature boosts PV module efficiency by 1.53%. Cooling advancements proved vital in contributing to sustainability in PV system installations

Energy, heat transfer and economic analysis of flat-plate solar collector utilizing SiO2 nanofluid / Mohd Faizal Fauzan

Solar thermal energy can be a good replacement for fossil fuel because it is clean and sustainable. However, the current solar technology is still not efficient and expensive. The effective way to increase the efficiency of solar collector is to use nanofluid. This study is carried out to analyze the impact on thermal performance, heat transfer and economic of a flat-plate solar collector when SiO2 nanofluid utilized as working fluid. The analysis is based on different volume flow rates and varying nanoparticles volume fractions. From the numerical study, it can be revealed that CuO have the highest thermal efficiency enhancement of up to 38.46% compared to water where else SiO2, TiO2 and Al2O3 performed almost similarly. However, SiO2 nanofluid is the cheapest and the most abundance materials on earth. Therefore, it is more suitable option. The experimental study has indicated that up to 27.2% increase in the thermal efficiency and 34.2% increase in exergy efficiency were achieved by using 0.2% concentration SiO2 nanofluid on solar collector compared to water as working fluid. The drawback of adding nanoparticles in the base fluids is the increase in viscosity of the working fluid that has led to increase in pumping power of the system and pressure drop in pipes. However, for low concentration nanofluids, only negligible effect in the pumping power and pressure drop is noticed. Using nanofluid could also improve the heat transfer coefficient by 28.26%, saving 280 MJ more embodied energy, offsetting 170 kg less CO2 emissions and having a faster payback period of 0.12 years compared to conventional water based solar collectors. Applying SiO2 nanofluid could improve the thermal efficiency, heat transfer and economic performance of a flat-plate solar collector

Comparative exergy analysis of selected fuels for internal combustion engines / Mohd Faizal Fauzan

This dissertation examines the detailed thermodynamics models for naturally aspirated gasoline and alternative fuelled to spark ignition internal combustion engines on the basis of ideal Otto cycle. A comparative study based on the first and second laws of thermodynamics are discussed here. The key parameters for analysis are considered as mean effective pressure (MEP), power, torque, exergetic efficiency, second law efficiency, and irreversibility. Air standard assumptions were taken consideration for the analyses. MEP, power output and torque for all alternative fuelled engines, are higher compared to that of a gasoline engine. Exergy due to heat and work are also discussed here. For heat exergy, only hydrogen exceeds gasoline while other alternative fuels have lower heat exergy than gasoline. But work (mechanical) exergy for all the alternative fuelled engines are higher than the gasoline engine. The Irreversibility or losses for the alternative fuelled engines are significantly lower than a gasoline engine. Alternative fuel engines have lower specific fuel consumption than the gasoline engine. Hence the 1st law and second law efficiency of the alternative fuelled engines are higher compared to that of gasoline. This is also due to having a high compression ratio associated with alternative fuelled internal combustion engine. Exergy heat transfer of alternative fuelled internal combustion engine is higher due to having high heat generation during combustion

Automated Water Irrigation System for Urban Farming

The advancement in knowledge and technology has benefited various types of industries worldwide including the agricultural sector. The developments in the traditional agricultural sector has created a new type of agronomy called, urban farming. This type of farming is usually done in the city or even in housing areas and apartments. The concept of this agricultural activity is to utilise limited amounts of available space for the planting of fruits and vegetables that can grow at a quick rate. This type of farming is small-scaled and requires low initial investments. However, the issue with urban farming is that water irrigation is usually done manually using human labour and is powered by electricity which is a non-renewable energy power source. Thus, the main objective of this research paper is to produce a new and improved small-scaled automated water irrigation system for urban farming that is not only self-sustainable but also powered by renewable energy. There were three types of analysis conducted that contained the major factors affecting a water irrigation system. These analyses are renewable energy, flow and economic analysis. Besides that, main design elements were also taken into consideration such as using renewable energy as a power source (Solar, Wind or Hydro), pump and motor power, pipe size, material, layout and cost, volumetric flow rate, head loss and actual pressure present in pipes. The results of the analysis justified that hydro energy was the best renewable energy to be used as a power source. The results also showed that a 500 W pump and motor set was most optimum to irrigate water in the urban farm. In addition, a 0.3 m underground pipe layout using ¾ inch rubber pipes was proven to be the most efficient for a new and improved water irrigation system. From the economic analysis conducted, the new and improved design of automated water irrigation system for urban farming was able to save up to RM 2364.58 annually with a Return on Investment (ROI) of about 6 months while showing profit within 1 year. The analyses conducted and results obtained proved that the new and improved design of automated water irrigation system for urban farming is not only cost efficient but is also environmentally friendly

An Experimental and Mathematical investigation of optimal tilt angle and effects of reflectors on PV energy production

The performance of the solar photovoltaic panels relies on its direction and tilt angle with respect to the horizontal to obtain better conversion efficiency. The tilt angle of the PV panel needs to be in proper location and position to obtain maximum power output from photovoltaics. The optimum tilt angle is generally calculated based on global, diffused, and direct radiation on the horizontal surface. This study focuses on the concept of the optimal tilt angle that improves the performance of the PV panel. The paper discusses the MATLAB mathematical modelling and experimental validation conducted at Nitte, India to determine the optimal tilt angle of PV panels of the region for maximum solar radiation. The investigation also includes the effect of three different types of reflectors on the PV panel for the obtained optimal tilt angle. The experimental results show that to get the optimum power output, the tilt angle needs to be changed every month. Hence monthly optimal tilt must be chosen for optimum power output. The results showed a PV panel with a focused mirror reflector produced higher power output compared to aluminum and stainless-steel reflectors