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Sky Image-Based Solar Irradiance Prediction Methodologies Using Artificial Neural Networks
摘要： In order to decelerate global warming, it is important to promote renewable energy technologies. Solar energy, which is one of the most promising renewable energy sources, can be converted into electricity by using photovoltaic power generation systems. Whether the photovoltaic power generation systems are connected to an electrical grid or not, predicting near-future global solar radiation is useful to balance electricity supply and demand. In this work, two methodologies utilizing artificial neural networks (ANNs) to predict global horizontal irradiance in 1 to 5 minutes in advance from sky images are proposed. These methodologies do not require cloud detection techniques. Sky photo image data have been used to detect the clouds in the existing techniques, while color information at limited number of sampling points in the images are used in the proposed methodologies. The proposed methodologies are able to capture the trends of fluctuating solar irradiance with minor discrepancies. The minimum root mean square errors of 143 W/m2, which are comparable with the existing prediction techniques, are achieved for both of the methodologies. At the same time, the proposed methodologies require much less image data to be handled compared to the existing techniques.
关键词： Artificial Neural Network,Photovoltaic Power Generation,Solar Energy,Global Horizontal Irradiance Prediction,Sky Image
更新于2025-09-23 15:21:21
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[IEEE 2017 International Renewable and Sustainable Energy Conference (IRSEC) - Tangier (2017.12.4-2017.12.7)] 2017 International Renewable and Sustainable Energy Conference (IRSEC) - The Role of Legislations and Incentives in the Growth of a PV Market in a Developing Country
摘要： The policy transition process of any subject has mainly 4 consecutive steps to implement: making the policy decision, forming the amendments and new legislations, defining the incentives and starting the investments. Then, the amount of these investments and their turnovers reveal whether the sector has grown successfully and sustainably. Consequently, forming reliable and effective amendments, legislation and incentives is the key for the success of any policy. Solar electricity market in the trade of electricity production via the renewable energy policy transition is a good example and barometer for the importance and success of policy making processes, especially after the new legislations and incentives. Thus, the question arises on whether a country having less solar radiation and stronger incentives performs better than a country having abundant resources but inefficient legislation or vice versa. When the global success stories and good practices on solar energy are analyzed, it is comprehended that they are achieved by the countries whose legislation and incentives are defined in the most reliable and fastest way possible. Subsequently, both the solar market and industrial growth are directed by the quality of legislation and incentives, mainly the feed-in tariff schemes. Others are the easiness of the bureaucracy by minimizing the paper works and lowering the soft costs of projects. All make the solar electricity sector much more competitive and widespread. This study analyzes the effect of the improvement of legislation and incentives on the maturation of Turkish solar electricity sector and the link between the growth of the sector and proper legislation and incentives practices. Necessary amendments are done as needed using the feed-back obtained from the practice in the field. As the frequency of the amendments to form better installed power has increased, the amount of legislations increased too. Moreover, the number of the industrial plants manufacturing PV modules has increased with a similar trend. This study checks the scope of this relation by questioning whether it is worldwide or depends on any other sui-generis situations of specific countries. As a result, it can also be argued that the major catalyzer of PV market expansion and industry development in Turkey is the strong, usable and to-the-point legislative and incentive schemes in parallel with global best practices.
关键词： legislation,photovoltaics,feed-in-tariff,Solar energy
更新于2025-09-23 15:21:21
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Improved Solar Energy Photoactivity over Defective BiOBr Ultrathin Nanosheets towards Pollutants Removal and Oxygen Evolution
摘要： Defective BiOBr nanosheets with ultrathin thickness and surface confined pits have been synthesized through a dual control of cetyltrimethyl ammonium bromide (CTAB) and polyvinyl pyrrolidone (PVP). The photocatalytic activity of the obtained defective BiOBr nanosheets was evaluated for the removal of rhodamine B (RhB), ciprofloxacin (CIP) and oxygen evolution from water. The as-prepared defective BiOBr nanosheets displayed significantly increased activity for pollutant degradation and oxygen evolution. The enhanced photocatalytic activity was ascribed to the improved light harvesting, suppression of charge recombination, and an increase in the number of active sites for photocatalytic reaction. The electronic structure of the defective BiOBr ultrathin nanosheets with confined pits has been tuned and thus varied the photocatalytic mechanism for pollutant degradation. The active species have changed from hole for BiOBr nanoplates to superoxide radical (O2??) and hole for defective BiOBr nanosheets determined by ESR analysis and trapping experiments.
关键词： Ultrathin nanosheets,Solar energy,Defects,BiOBr,Photocatalytic
更新于2025-09-23 15:21:21
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Exergoeconomic analysis and optimization of a concentrated sunlight-driven integrated photoelectrochemical hydrogen and ammonia production system
摘要： The study presented here concerns a comprehensive investigation on exergoeconomic analysis and optimization of an integrated system for photoelectrochemical hydrogen and electrochemical ammonia production. The present integrated system consists of a solar concentrator, spectrum-splitting mirrors, a photoelectrochemical hydrogen production reactor, a photovoltaic module, an electrochemical ammonia production reactor and support mechanisms. Detailed thermodynamic and exergoeconomic analyses are initially conducted to determine the performance of the integrated system namely; efficiency and total cost rate. The obtained performance parameters are then optimized to yield the minimum cost rate and maximum efficiency under given constraints of the experimental system. The highest capital cost rates are observed in the photoelectrochemical hydrogen and electrochemical ammonia production reactors because of high procurement costs and electricity inputs. The optimized values for exergy efficiency of the integrated system range from 5% to 9.6%. The photovoltaic and photoelectrochemical cell areas and solar light illumination mainly affect the overall system efficiencies. The optimum efficiencies are found to be 8.7% and 5% for the multi-objective optimization of hydrogen production and integrated ammonia production system, respectively. When the exergy efficiency of the integrated system is maximized and the total cost rate is minimized at the same time, the total cost rate of the system is calculated to be about 0.2 $/h. The cost sensitivity analysis results of the present study show that the total cost rate of the system is mostly affected by the interest rate and lifetime of the system.
关键词： Exergoeconomics,Solar energy,Hydrogen,Optimization,Photoelectrochemical process,Ammonia
更新于2025-09-23 15:21:21
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Perfect metamaterial absorber with high fractional bandwidth for solar energy harvesting
摘要： A new perfect metamaterial absorber (PMA) with high fractional bandwidth (FBW) is examined and verified for solar energy harvesting. Solar cells based on perfect metamaterial give a chance to increase the efficiency of the system by intensifying the solar electromagnetic wave that incident on the device. The designed structure is mostly offered in the visible frequency range so as to exploit the solar’s energy efficiently. Parametric investigations with regard to the measurements of the design structure are fulfilled to characterize the absorber. The finite-difference time-domain (FDTD) method-based CST simulator was used to keep the pattern parameters and absorbance analysis. The metamaterial shows almost 99.96% and 99.60% perfect absorption at 523.84 THz and 674.12 THz resonance frequencies. Moreover, absorption’s FBW is studied, and 39.22% FBW is found. The results confirm that the designed PMA can attain very high absorption peak at two modes such as transverse electric (TE) and transverse magnetic (TM) mode. Other than the numerical outcomes demonstrated that the suggested configuration was also polarization angle insensitive. In addition, the change of absorbance of the structure has provided a new kind of sensor applications in these frequency ranges. Therefore, the suggested metamaterial absorber offers perfect absorption for visible frequency ranges and can be used for renewable solar energy harvesting applications.
关键词： solar energy harvesting,polarization angle insensitive,perfect metamaterial absorber,visible frequency range,high fractional bandwidth
更新于2025-09-23 15:21:21
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Thin film technology for solar steam generation: A new dawn
摘要： The sun is considered as the most promising abundant renewable energy source that can be exploited to solve many of human beings’ challenges such as energy and water scarcity. Solar energy can be utilized in steam and vapor generation processes which has a great importance in many engineering applications such as water desalination, domestic water heating, and power generation. However, dilute solar flux (～1000 W/m2) cannot supply the absorber with enough power required to overcome water latent heat of vaporization to evaporate water. Optical concentrators such as parabolic trough collector, parabolic dish reflector, and circular Fresnel lens can be used to concentrate the solar radiation to achieve the required power however they suffer from complexity and high cost. Moreover, the efficiency of the conventional solar desalination devices such as solar stills decreases dramatically with increasing bulk water quantity, due to the heat loss to bulk water. Therefore, the need to solar steam generation (SG) devices, that localize heating on a thin layer of water rather than the water bulk, arises. Thin film technology has shown promising progress in SG in which solar energy is utilized to wastewater desalination. The past five years have seen a significant surge in the development of thin film based SG devices. In this review, recently developed thin film-based SG devices are scrutinized with respect to their physical mechanisms, fabrication methods, structure, advantages, and disadvantages. Different types of thin-film materials, including: metal-based nanoparticles, metal oxides, carbon-based materials, polymers, etc.; as well as different substrates materials, including: wood, paper, cotton fabric, carbon fabric, polystyrene foam, and gauze, have been discussed. Moreover, different preparation and synthetization methods of the steam generation devices have been discussed. Suggestions for future research directions are also presented.
关键词： Substrate materials,Heat localization,Solar energy,Steam generation,Deposition techniques,Thin film technology
更新于2025-09-23 15:21:21
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How photovoltaics can contribute to GHG emission reductions of 55% in the EU by 2030
摘要： The new European Commission plans to raise the greenhouse gas (GHG) emissions reduction target from 40% towards 55% by 2030 and make Europe the first climate-neutral continent by 2050. Achieving this will require accelerated energy efficiency measures, deeper electrification of sectors currently consuming conventional fuels and the deployment of more renewables, faster. This opinion article looks specifically at the role of photovoltaics (PV), based on scenarios from the Commission’s 2018 long-term strategy (LTS) for energy and climate. To reach a 55% GHG emissions reduction, the cumulative PV capacity in the EU and the UK would need to surge to 455–605 GW, depending on the strategic policy scenario. This implies a compound annual growth rate between 12 and 15% in the timeframe 2020–203 to increase the annual PV market from approximately 16.5 GW in 2019 to 50–80 GW by 2030. Such a volume can provide the basis for reviving the European solar manufacturing industry as well as creating more than 100 000 jobs along the value chain.
关键词： Energy system model,Photovoltaics,Solar energy,European green deal,Energy policy
更新于2025-09-23 15:21:01
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Design, optimization and performance comparison of solar tower and photovoltaic power plants
摘要： This paper compares two main technologies of solar to electrical energy conversion, namely solar tower (ST) and photovoltaic (PV). For a fair comparison, a 100 MW same sized ST and PV plants are designed for a region with very good direct normal irradiance (DNI) and global horizontal irradiance (GHI). The initial design of the ST plant is optimized for solar multiple and thermal energy storage hours, and the PV plant is optimized for the optimal distance between parallel PV arrays. The ST plant has superior annual energy output of 513040.16 MWh compared to 270754.6 MWh from PV plant and capacity utilization factor of 58.6% in comparison to 30.9% from PV plant. On the contrary, the land use factor and solar to electric ef?ciency (SEE) of the PV plant is superior to ST plant while levelized cost of energy of ST plant is 2.83 times higher than the PV plant. Although ST plant has superior technical performance but way better economic performance of PV plant makes it the stand out solar to electrical energy technology for a location with promising GHI and DNI. This paper provides very useful guidelines for the policymakers to select a particular technology for the future solar-based power generation projects.
关键词： Levelized cost of energy,Photovoltaic,Solar energy,DNI,Solar tower,GHI
更新于2025-09-23 15:21:01
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[Energy, Environment, and Sustainability] Advances in Solar Energy Research || Introduction to Advances in Solar Energy Research
摘要： A lot of activity has been taking place in the research community over the decades to efficiently harness solar energy. One way this is fuelled is by the support from the governments which promote the implementation of large-scale projects—whether it be for electric power generation (using PV), or for water heating using solar thermal collectors. These activities involve the efforts of the industry, which keep pace with the latest technology in the world, and are in a race to provide the most reliable technological solution to the customer for harnessing solar energy in an economical and robust manner. This has been the backdrop theme of almost all the chapters included in this book, which have been contributed by various authors from across the world. This is the first chapter of the book, and thus provides an overview of the various topics that will be covered in this book, ranging from an energy roadmap for the future, to technologies advances in the field of photovoltaics and solar cells (DSSC—Dye-Sensitized Solar Cells). It also includes details of solar thermal collector, along with the discussion about its heat transfer aspects. Apart from the two primary uses of solar energy—electric power generation and water heating—there are numerous applications for which it has been used over the years. Several such applications are also discussed in some of the subsequent chapters, such as refrigeration, desalination, gasification, and cooking.
关键词： Photovoltaics,Applications,Solar thermal systems,Solar energy,DSSC,Solar cells
更新于2025-09-23 15:21:01
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Unified theory of plasmon-induced resonance energy transfer and hot electron injection processes for enhanced photocurrent efficiency
摘要： Plasmons in metal nanoparticles (MNPs) promise to enhance solar energy conversion in semiconductors. Two essential mechanisms of enhancement in the near-field regime are hot electron injection (HEI) and plasmon-induced resonance energy transfer (PIRET). Individual studies of both mechanisms indicate that the PIRET efficiency is limited by the short lifetime of the plasmon, whereas the hot electrons result from the plasmon decay. The development of a unified theory of the coupled HEI and PIRET processes is fundamentally interesting and necessary for making reliable predictions but is complicated by the multiple interactions between various components that participate in the enhancement process. In this paper, we use the model-Hamiltonian approach to develop a combined theoretical framework including both PIRET and HEI. The coupled dynamics as well as the time evolution of hot electron energy distribution are studied. The theory further predicts an interference-induced asymmetry in the spectral dependence of PIRET, which can be used to distinguish it from HEI. As the relative contributions of PIRET and HEI strongly depend on the size of the MNPs, this presents itself as a simple route to control the strength of their contributions. The results presented here can further guide future applications of plasmonic solar energy harvesting.
关键词： plasmon,metal nanoparticles,hot electron injection,solar energy conversion,plasmon-induced resonance energy transfer
更新于2025-09-23 15:21:01