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Integrated sizing of hybrid PV-wind-battery system for remote island considering the saturation of each renewable energy resource
摘要： The proliferation of renewable energy particularly the combination of solar-wind power and storage bank, is likely to be occupied throughout the world, to mitigate the local energy concerns, improve the energy supply opportunities for off-grid communities and vitiate environmental pollution concerns as well as ease the intensity of energy consumption. To mitigate the disharmony between renewable energy (RE) generation and supply, a cost-optimal autonomous hybrid renewable energy system is developed and comparatively analyzed, considering the saturation level of each involved RE source based on various technical and economic key indicators. This study proposes a mathematical model to comprehensively analyze the effect of varying saturation, i.e. increasing the saturation of one resource meanwhile decreasing the ratio of other resource, on battery bank size, state of charge (SOC), loss of power supply, excess energy, net present cost, levelized cost of energy (COE) and payback time. A saturation factor is introduced, from 0 to 1 value with step size 0.02, where zero represents the wind-only system and one represents the solar-only system. Three different systems are considered, with different wind turbine sizes (total 150 configurations), to comparatively analyze the different energy systems and the result reveals that smaller wind turbine size (2 kW) with 90% saturation of wind energy is the most cost-effective system for the proposed remote island. In addition, the solar-alone and wind-alone systems are compared, showing that the wind-only system can provide good performance as compare to solar-only. Furthermore, the effects of the saturation factor on COE, battery bank size, SOC, excess energy, system reliability and different load demands are analyzed. Energy balance analysis of whole year and simulation performance of the system is accomplished to verify the system reliability. Sensitivity analysis reveals that wind energy, battery cost and load has a significant impact on COE than other factors.
关键词： Hybrid Renewable system reliability,Cost of energy,Net present cost,Renewable energy saturation,Energy balance,Solar-wind-battery system
更新于2025-09-23 15:23:52
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Evaluation of Radiation Characteristics of Xenon Short Arc Lamp by Numerical Simulation; 数値解析を用いたキセノンショートアークランプの放射特性評価;
摘要： In this study, an arc numerical simulation model of xenon short arc lamp was developed by modifying numerical simulation model of free burning arc. The influence of the difference in the filling gas pressure on the energy consumed by the lamp voltage, current and gas radiation was investigated. It became clear that the radiation power of the xenon arc lamp strongly depends on the filling gas pressure. Furthermore, when the lamp is turned on with constant power, the radiation efficiency is determined by the balance between the radiation power density and the high temperature arc volume, and as a result, it is clear that the maximum value exists of the radiation power fraction.
关键词： Numerical Simulation,Xenon Arc Lamp,Radiation,Xenon,Energy Balance
更新于2025-09-23 15:23:52
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Metabolic profiling of early lactation dairy cows using milk mid-infrared spectra
摘要： Metabolic disorders in early lactation have negative effects on dairy cow health and farm profitability. One method for monitoring the metabolic status of cows is metabolic profiling, which uses associations between the concentrations of several metabolites in serum and the presence of metabolic disorders. In this cross-sectional study, we investigated the use of mid-infrared (MIR) spectroscopy of milk for predicting the concentrations of these metabolites in serum. Between July and October 2017, serum samples were taken from 773 early-lactation Holstein Friesian cows located on 4 farms in the Gippsland region of south-eastern Victoria, Australia, on the same day as milk recording. The concentrations in sera of β-hydroxybutyrate (BHB), fatty acids, urea, Ca, Mg, albumin, and globulins were measured by a commercial diagnostic laboratory. Optimal concentration ranges for each of the 7 metabolites were obtained from the literature. Animals were classified as being either affected or unaffected with metabolic disturbances based on these ranges. Milk samples were analyzed by MIR spectroscopy. The relationships between serum metabolite concentrations and MIR spectra were investigated using partial least squares regression. Partial least squares discriminant analyses (PLS-DA) were used to classify animals as being affected or not affected with metabolic disorders. Calibration equations were constructed using data from a randomly selected subset of cows (n = 579). Data from the remaining cows (n = 194) were used for validation. The coefficient of determination (R2) of serum BHB, fatty acids, and urea predictions were 0.48, 0.61, and 0.90, respectively. Predictions of Ca, Mg, albumin, and globulin concentrations were poor (0.06 ≤ R2 ≤ 0.17). The PLS-DA models could predict elevated fatty acid and urea concentrations with an accuracy of approximately 77 and 94%, respectively. A second independent validation data set was assembled in March 2018, comprising blood and milk samples taken from 105 autumn-calving cows of various breeds. The accuracies of BHB and fatty acid predictions were similar to those obtained using the first validation data set. The PLS-DA results were difficult to interpret due to the low prevalence of metabolic disorders in the data set. Our results demonstrate that MIR spectroscopy of milk shows promise for predicting the concentration of BHB, fatty acids, and urea in serum; however, more data are needed to improve prediction accuracies.
关键词： mid-infrared spectral prediction,metabolic profile,energy balance,ketosis
更新于2025-09-23 15:22:29
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[IEEE 2019 International Topical Meeting on Microwave Photonics (MWP) - Ottawa, ON, Canada (2019.10.7-2019.10.10)] 2019 International Topical Meeting on Microwave Photonics (MWP) - 300 GHz Photonic Self-Mixing Imaging-System with vertical illuminated Triple-Transit-Region Photodiode Terahertz Emitters
摘要： In this paper, we report a phase-sensitive photonic THz two-tone self-mixing imaging system, comprising a self-developed vertical illuminated triple transit region photodiode (TTR-PD) and a commercial square law Schottky barrier diode as THz emitter and THz detector, respectively. Using the two-tone self-mixing approach, the phase information of a device-under-test can be extracted by down-mixing two THz signals inside the SBD, whereas the phase information remains in the output signal. The THz tones are generated by two free-running lasers and the TTR-PD, while one optical signal is externally modulated for double sideband carrier suppression. By means of the self-mixing, the phase noises of the free running lasers are canceled out. Using a second PD for the trigger, lock-in detection allows fast imaging speed, only limited by the integration constant. Beside the imaging system, we present the characteristics of the used vertically illuminated terahertz triple transit region photodiodes with thin depletion zone and small active areas. Numerical analysis by energy-balance model based TCAD simulations show transit-time limitations over 200 GHz, due to the electron field management within the active photodiode layers and the resulting high electron velocities. Therefore, the fabricated TTR-PDs show a flat ±2 dB frequency response within the frequency range from 225 GHz to 305 GHz. By employing the proposed photonic two-tone imaging system with the fabricated TTR-PDs, amplitude and phase difference vector images are taken at 299.5 GHz and 300.5 GHz. Metal and acrylic glass items inside a paper envelope are clearly visible, which demonstrates the potential of the system.
关键词： energy balance,self-mixing,TCAD,Terahertz spectroscopy,terahertz imaging,terahertz photodiodes
更新于2025-09-19 17:13:59
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Advances in solar photovoltaics: Technology review and patent trends
摘要： Against the pressing challenges of climate change and fossil fuel depletion, renewable energy sources such as solar photovoltaics (PV) are considered a clean and sustainable alternative. PV technologies have grown into a substantial field of research and development through large stocks of scientific publications and patents. Besides cell technologies, the balance of system (BoS) components such as panels, electronics and energy storage form an important research area. The present article studies the development of the PV technological system using patent indicators. It is composed of three parts: First, it defines the system by thoroughly reviewing the various cell and BoS technologies. Second, it introduces a novel methodical approach for identifying its relevant patents. In that sense, the paper contributes with an accurate inventory of international patent classes for PV system. Finally, the geographical, organizational and technical trends over the past six decades are analysed along with a review of the most influential inventions. The analysis shows that 95% of the PV patent applications were filed by inventors from seven countries: Japan, Korea, China, USA, Germany, Taiwan, and France. Most patents were filed by companies and related to thin-film and crystalline-silicon cells as well as panel encapsulation and supporting structures. The analysis reviews the quantity, quality and technological specialization within countries’ patent profiles. It further provides an overview of the technological landscape and freedom-spaces available for manufacturers.
关键词： PV cell technologies,IPC classes inventory,Renewable energy,Balance of system,Solar photovoltaics,Sectoral identification,Patent trends
更新于2025-09-16 10:30:52
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Performance study of a dual-fluid photovoltaic thermal collector with reflection and refraction solar concentrators
摘要： The temperature of a photovoltaic (PV) plate increases with increasing absorbed irradiation, leading to degradation of the electrical efficiency of the PV cells. The heat can be dissipated by air or water to prevent the deterioration of the cells. In this study, a concentrating photovoltaic thermal (PV-T) dual-fluid solar collector is proposed in which two types of concentrators are integrated. The collector’s performance was analysed with air and water as the working fluids. Analytical expressions were derived from the energy balance equations for each component of the collector. The mean temperature values of the PV plate, air inlet/outlet, water inlet/outlet, glaze and collector back wall were experimentally recorded under different fluid mass flow rates and solar irradiations. The readings were then used to compute the thermal and electrical efficiencies of the collector. The results obtained from the numerical and experimental analyses were compared and evaluated by employing the mean absolute percentage error method. The results show that incorporating two fluids increases the thermal and electrical efficiencies. The total thermal and electrical efficiencies achieved are 67.00% and 13.02%, respectively, at air and water mass flow rates of 0.0103 kg/s and 0.0164 kg/s, respectively, and a solar irradiation of 650 Wm?2. The outcomes of this research are expected to help advance the designs of dual-fluid PV-T solar collectors and offering a broader range of thermal applications.
关键词： reflection,photovoltaic,thermal,dual fluid,refraction,solar,collector,energy balance
更新于2025-09-16 10:30:52
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Balancing urban density, energy performance and environmental quality in the Mediterranean: a typological evaluation based on photovoltaic potential
摘要： As research on the correlation between urban design and environmental performance is still lacking, the following long-standing question still stands – How far can we densify urban districts without sacrificing their energy balance and indoor environmental quality? This question served as the starting point for a parametric typological study conducted at the block scale in the context of Tel Aviv, with the overall aim of promoting performance driven design of Mediterranean urban environments. Dynamic input parameters included fenestration ratio, aspect ratios and floor area ratios of 5 different building typologies in both office and residential land uses. Environmental outputs included energy cooling loads, spatial daylight autonomy and the monthly average load match between energy demand and photovoltaic energy supply. The courtyard typology was found to achieve the best performance in terms of monthly Load Match, however mostly in residential uses of lower density. Although the high-rise typology offered the best daylight conditions, it recorded the worse performance in terms of energy balance and energy cooling demand. Results demonstrate the potential of a parametric typological workflow to effectively indicate the tradeoffs between single building and urban scale design considerations. This potential could be harnessed to assess the environmental feasibility of net zero energy typologies in Mediterranean climates and will be used for district energy studies as part of future work.
关键词： urban energy balance,energy driven urban design,Urban density,building typologies,urban environmental performance
更新于2025-09-12 10:27:22
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Monitoring Evapotranspiration with Remote Sensing Data and Ground Data Using Ensemble Model Averaging
摘要： Evapotranspiration (ET) can be mapped using thermal infrared and spectral reflectance data. Various ET models have been developed but there was no competitive evaluation of them over a large range of situations. Ensemble model averaging is a tool that can be used for deriving ET from multi-model simulations. In this study, we used bayesian model averaging, which consists in weighting each model according to their performances when deriving the ensemble average. It was applied to the monitoring of ET over a saltmarsh scrub area in South France from MODIS data. ET monitoring was improved (RMSE = 0.57 mm d-1) when using a weighted averaging procedure as compared to the performances of a simple average or to the performances of each individual model.
关键词： thermal infrared,energy balance,ensemble modelling,contextual models,evapotranspiration
更新于2025-09-10 09:29:36