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Assessing the Effect of Incentive Policies on Residential PV Investments in Colombia
摘要： As the cost of solar photovoltaic (PV) falls, their potential for transforming modern electricity generation increases. Solar PV provides a simpler way of producing clean and affordable energy, which makes it an attractive investment. Great investments in solar PV have occurred in industrialized countries, but government efforts to promote this technology have not been effective in nonindustrialized countries. Despite this, some of these countries may have a high solar PV potential, such as Colombia, where policies to encourage solar PV are only just starting to take place. Therefore, this paper proposes a simulation model to assess different policies—feed-in tariff, net metering, and capital subsidy—to promote solar PV investments in the Colombian residential sector. Policies are assessed considering the criteria of efficiency and effectiveness. Simulation results suggest that (i) net metering is the most efficient policy with a cost indicator of 20,298 USD/MW; (ii) feed-in tariff is the most effective policy as it reaches the highest level of avoided CO2 emissions—4,792,823 million tons of CO2—and a meaningful PV installed capacity of 7522 MW; (iii) capital subsidy is the least efficient policy as it has the highest cost indicator of 509,616 USD/MW.
关键词： net metering,feed-in tariff,capital subsidy,PV adoption,effectiveness,CO2 emissions,efficiency
更新于2025-09-23 15:21:21
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A Monte Carlo based dosimetric characterization of Esteya <sup>?</sup> , an electronic surface brachytherapy unit
摘要： The purpose of this work is threefold: First, to obtain the phase-space of an electronic brachytherapy (eBT) system designed for surface skin treatments. Second, to explore the use of some efficiency enhancing (EFEN) strategies in the determination of the phase-space. Third, to use the phase-space previously obtained to perform a dosimetric characterization of the Esteya eBT system. Methods: The Monte Carlo study of the 69.5 kVp x-ray beam of the Esteya? unit (Elekta Brachytherapy, Veenendaal, The Netherlands) was performed with PENELOPE2014. The EFEN strategies included the use of variance reduction techniques and mixed Class II simulations, where transport parameters were fine-tuned. Four source models were studied varying the most relevant parameters characterizing the electron beam impinging the target: the energy spectrum (mono-energetic or Gaussian shaped), and the electron distribution over the focal spot (uniform or Gaussian shaped). Phase-spaces obtained were analyzed to detect differences in the calculated data due to the EFEN strategy or the source configuration. Depth dose curves and absorbed dose profiles were obtained for each source model and compared to experimental data previously published. Results: In our EFEN strategy, the interaction forcing variance reduction (VRIF) technique increases efficiency by a factor ~ 20. Tailoring the transport parameters values (C1 and C2) does not increase the efficiency in a significant way. Applying a universal cutoff energy EABS of 10 keV saves 84% of CPU time whilst showing negligible impact on the calculated results. Disabling the electron transport by imposing an electron energy cutoff of 70 keV (except for the target) saves an extra 8% (losing in the process 1.2% of the photons). The Gaussian energy source (FWHM = 10%, centered at the nominal kVp, homogeneous electron distribution) shows characteristic K-lines in its energy spectrum, not observed experimentally. The average photon energy using an ideal source (mono-energetic, homogeneous electron distribution) was 36.19 ± 0.09 keV, in agreement with the published measured data of 36.2 ± 0.2 keV. The use of a Gaussian-distributed electron source (mono-energetic) increases the penumbra by 50%, which is closer to the measurement results. The maximum discrepancy of the calculated percent depth dose with the corresponding measured values is 4.5% (at the phantom surface, less than 2 % beyond 1 mm depth) and 5% (for the 80% of the field) in the dose profile. Our results agree with the findings published by other authors and are consistent within the expected Type A and B uncertainties. Conclusions: Our results agree with the published measurement results within the reported uncertainties. The observed differences in PDD, dose profiles and photon spectrum come from three main sources of uncertainty: inter-machine variations, measurements and Monte Carlo calculations. It has been observed that a mono-energetic source with a Gaussian electron distribution over the focal spot is a suitable choice to reproduce the experimental data.
关键词： simulation efficiency,Monte Carlo simulation,electronic brachytherapy,surface treatment,dosimetry,x-ray source
更新于2025-09-23 15:21:21
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Time Dependent Facile Hydrothermal Synthesis of TiO2 Nanorods and their Photoelectrochemical Applications
摘要： In the present investigation, we report facile hydrothermal synthesis of TiO2 nanorods with high density rutile phase on Transparent Conducting Oxide (TCO) for enhanced solar cell application. The structural, optical, morphological, compositional and electrochemical properties are investigated by detailed XRD, UV-Vis-NIR spectrophotometer, FESEM, TEM, EDAX, XPS and photoelectrochemical studies. It is demonstrated that, the deposited TiO2 thin film shows pure rutile phase with tetragonal crystal structure. Optical spectra showed strong light absorption in UV region and FESEM images confirm the time dependent growth of TiO2 nanorods. EDAX and XPS Spectra confirm the formation of pure TiO2 nanorods. Photoelectrochemical performance with respect to time dependent growth of TiO2 nanorods showed highest photoconversion efficiency = 5.1%.
关键词： Hydrothermal synthesis,Photoelectrochemical cell property,Single crystalline,Photoconversion efficiency,TiO2 nanorods,Transparent conducting oxide (TCO)
更新于2025-09-23 15:21:21
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[Energy, Environment, and Sustainability] Advances in Solar Energy Research || Supercritical Carbon Dioxide Solar Thermal Power Generation—Overview of the Technology and Microchannel Receiver Development
摘要： The supercritical carbon dioxide (sCO2) power cycle is being considered for solar thermal central receiver systems in the United States. The cycle lends to increased high-temperature input that is expected of the next-generation concentrating solar thermal power (CSP) systems. Power block efficiencies of about 50% can be achieved for recompression cycles at an input temperature of approximately 720 °C. Additionally, the power block is compact and less complex, raising the possibility of using thermal-storage-coupled CSP sCO2 technologies for modular (*100 MW) peak-load power plants. Three pathways toward providing solar thermal input to the sCO2 cycle have been proposed by various research groups—the molten salt receiver pathway, the solid particle receiver pathway, and the gas-phase receiver pathway. The first two technologies have the advantage of sensible thermal storage within the solid/fluid medium passing through the receiver. In the gas receiver pathway, there is a need for coupling a sensible or latent heat storage technology. Several key technologies are needed to enable the realization of the sCO2 solar thermal technology, key among them being the receiver and thermal storage. In this chapter, some of the key gas-phase receiver technologies are discussed. The group’s past and recent work on the development of microchannel solar thermal receivers for sCO2 is emphasized.
关键词： Solar thermal,Efficiency,Supercritical carbon dioxide,Microchannel,Receiver,Concentrating solar power
更新于2025-09-23 15:21:21
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Factors Having a Crutial Impact on Energy Efficiency of Floodlighitng
摘要： Floodlighting designs have only been analysed in terms of visual and aesthetic beauty up to now. Research in the field of floodlighting has also focused on other aspects of this type of lighting in recent years. The energy efficiency issue and the impact on light pollution are the most crucial aspects. These issues have not yet been properly explored in the literature. Significant factors which affect the issue of the engineering aspect of floodlighting have to be determined and studied carefully because of their high importance. The main aim of this paper is to present the key factors which have a crucial impact on energy efficiency and light pollution in the field of floodlighting. These factors are: the direction and location of the lighting equipment, luminous intensity distribution, light output ratio, the method of floodlighting and the spectral power distribution of a light source, as well as the spectral distribution of the reflectance from the illuminated surface. Each of these factors are precisely commented on. These are presented by means of a calculation, a measurement or a visualization example, which clearly allow the crux of the problem to be analysed in the easiest way. The research shows that the problem of improving floodlighting design in respect of energy efficiency and light pollution is a complex and exacting problem for a lighting designer. It definitely requires the creation of an individual and unified system of assessment. It ought to take into account all the crucial factors and be simple, understandable and easy to use. Development of such a system is underway at the Lighting Technology Division of Warsaw University of Technology. It will soon be finalized in the form of a doctoral dissertation by one of the authors of this paper.
关键词： energy efficiency,lighting technology,floodlighting utilization factor,light pollution,floodlighting
更新于2025-09-23 15:21:21
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Analytical Estimation of Optical Efficiency of Cylindrical Light-Tubes Under Various CIE Sky Types
摘要： The light pipes represent a common device for enhancement of daylight amount in buildings with complex architecture and insufficient lighting by vertical windows or in underground spaces. The advantage of straight vertical light pipes is that they transport light into interior spaces from the whole sky vault independently on solar azimuth. So mainly at higher solar altitudes and under clear sky conditions they can significantly contribute in buildings. The optical efficiency of a light pipe strongly depends on number of reflections of the light beams between the particular interfaces. There are available some numerical tools based on ray-tracing algorithms that enable to calculate the efficiency with high precision under given conditions. However, such calculations are adequately time-consuming and so non- attractive for routine (mass) modelling. This contribution presents an analytical method for prediction of the optical efficiency of straight light-pipes which is applicable on 15 types of sky luminance defined by CIE. Due to the analytical approach, the calculation is very fast. The method is validated by accurate numerical simulations for all the sky types and at various pipe aspect ratios. Mainly in the extreme cases of clear and overcast sky, the results are in good agreement.
关键词： light pipe,analytical prediction,optical efficiency,CIE sky models
更新于2025-09-23 15:21:21
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Improving performance of thermally activated delayed fluorescence emitter by extending its LUMO distribution; 通过扩展LUMO分布提高热激活延迟荧光材料的性能;
摘要： An optimized compound 9-(9,9-dimethylacridin-10(9H)-yl)-6H-benzo[c]ch-romen-6-one (MAB) was designed and synthesized based on our previously reported TADF emitter 6-(9,9-dimethylacridin-10(9H)-yl)-3-methyl-1H-isochromen-1-one (MAC) to further improve the performance of thermally activated delayed fluorescence (TADF) emitters. With the additional phenyl in coumarin-contained plane, MAB possesses an extended distribution of the lowest unoccupied molecular orbitals (LUMO), and thus realizes reduced electron exchange between the frontier molecular orbitals and a stretched molecular dipole moment compared with MAC. MAB based organic light-emitting diode (OLED) exhibits a remarkable maximum external quantum efficiency (EQE) of 21.7%, which is much better than the maximum EQE of MAC-based OLED with a value of 12.8%. Our work proves that extending the distribution of LUMO is a simple but effective method to improve the efficiency of TADF emitter.
关键词： lumo distribution,external quantum efficiency,thermally activated delayed fluorescence,organic light-emitting diode
更新于2025-09-23 15:21:21
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Size and shape control of monoclinic vanadium dioxide thermochromic particles for smart window applications
摘要： Monoclinic vanadium dioxide (VO2 (M)) was synthesized by the thermolysis of vanadyl ethylene glycolate, which was obtained easily by the precipitation of a vanadium precursor in ethylene glycol solution under atmospheric conditions. The particle size and shape were easily controlled by altering the molar concentration of the vanadium precursor. Thereafter, VO2 (M) composite films were prepared by mixing with poly(vinylpyrrolidone). A high concentration of the vanadium precursor produced small spherical nanoparticles ≈30 nm in size, while lower concentrations afforded large rod-like particles. The composite films fabricated with the VO2 (M) nanoparticles exhibited high luminous transmittance (Tlum = 79%) and IR modulation ability (ΔTIR = 5.6%). This work demonstrates that these VO2 (M) composite films show promise for application in smart windows.
关键词： solar modulation ability,Energy efficiency,size and shape tuning,high luminous transmittance,VO2 (M) particle,thermochromic coating
更新于2025-09-23 15:21:21
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Energy and exergy analyses of a solar powered multi-effect cooling cycle
摘要： This study aims to assess the thermodynamic performance of a novel solar powered multi-effect cooling cycle through the cascaded utilisation of energy and exergy. The effects of parameters such as: direct normal irradiation (DNI), turbine inlet temperature, turbine back pressure, and evaporator temperature of ERC were ascertained on the energetic and exergetic performance of the cycle. Exergy destruction occurs throughout the plant components is quantified and illustrated using an exergy flow diagram, and compared to the corresponding energy flow diagram. The exergy efficiency of the cycle was significantly less than its corresponding energy efficiency. Computational analysis further revealed that the maximum exergy losses of more than 34% occur in the solar field followed by 7.25% and 6.75% in the components of ARC and CRC, respectively. Percentage of these exergy losses indicates the sites where the efforts should be made to improve the real performance of proposed cooling cycle.
关键词： ejector,solar,efficiency,refrigeration,absorption
更新于2025-09-23 15:21:21
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Bi-Exciton Dissociation Dynamics in Nano-Hybrid Au-CuInS <sub/>2</sub> Nanocrystals
摘要： Multiexciton harvesting from semiconductor quantum dot has been a new approach for improving the solar cell efficiency in Quantum Dot Sensitized Solar Cells (QDSC). Till date, relation between multiexciton dissociation in metal?semiconductor nanohybrid system and boosting the power conversion efficiency (PCE) of QDSC were never discussed. Herein we report a detailed spectroscopic investigation of biexciton dissociation dynamics in copper indium sulfide (CuInS2, also referred as CIS) and Au-CIS nanohybrid, utilizing both time-resolved PL and ultrafast transient absorption (TA) techniques. Ultrafast transient absorption suggests the formation of bi-exciton in CIS NCs which efficiently dissociates in Au-CIS nanohybrids. Maximum multiexciton dissociation (MED) efficiency is determined to be ~ 80% at higher laser fluency, however it was observed to be 100% at lower laser fluency. Prior to exciton dissociation electrons are captured by Au NP in the nanohybrid from the conduction band of CIS NCs which is energetically higher than Fermi level of Au. Here we demonstrate the proof-of-concept in multi-electron dissociation which may provide a new approach for improving the efficiency in QDSSCs, where we found power conversion efficiency (PCE) of Au-CIS nanohybrids up to 2.49% as compared to ~1.06% ~for pure CIS NCs in similar condition. This finding can be an efficient approach towards the design and development of efficient solar cell and optoelectronic devices using the principles of multiexciton generation and extracting multiexcitons in metal-semiconductor nanohybrid system.
关键词： copper indium sulfide,biexciton dissociation dynamics,Quantum Dot Sensitized Solar Cells,power conversion efficiency,ultrafast transient absorption,Multiexciton harvesting,Au-CIS nanohybrid
更新于2025-09-23 15:21:21