The sun's total and spectral irradiance for solar energy applications and solar radiation models
TL;DR: In this article, a composite time series of total solar irradiance spaceborne measurements is used to predict the sun's irradiance within 0.1% on average, as accurately as current measurements.
About: This article is published in Solar Energy.The article was published on 2004-04-01. It has received 843 citations till now. The article focuses on the topics: Solar irradiance & Solar constant.
Citations
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TL;DR: The uvspec program, a suite of tools for radiative transfer calculations in the Earth's atmosphere, and additional tools included with libRadtran are described and realistic examples of their use are given.
Abstract: . The libRadtran software package is a suite of tools for radiative transfer calculations in the Earth's atmosphere. Its main tool is the uvspec program. It may be used to compute radiances, irradiances and actinic fluxes in the solar and terrestrial part of the spectrum. The design of uvspec allows simple problems to be easily solved using defaults and included data, hence making it suitable for educational purposes. At the same time the flexibility in how and what input may be specified makes it a powerful and versatile tool for research tasks. The uvspec tool and additional tools included with libRadtran are described and realistic examples of their use are given. The libRadtran software package is available from http://www.libradtran.org.
1,309 citations
TL;DR: Ti2 O3 nanoparticles with high performance of photothermal conversion are demonstrated for the first time and shows potential use in seawater desalination and purification.
Abstract: Ti2 O3 nanoparticles with high performance of photothermal conversion are demonstrated for the first time. Benefiting from the nanosize and narrow-bandgap features, the Ti2 O3 nanoparticles possess strong light absorption and nearly 100% internal solar-thermal conversion efficiency. Furthermore, Ti2 O3 -nanoparticle-based thin film shows potential use in seawater desalination and purification.
755 citations
TL;DR: In this paper, a comprehensive and systematic review of the direct forecasting of PV power generation is presented, where the importance of the correlation of the input-output data and the preprocessing of model input data are discussed.
Abstract: To mitigate the impact of climate change and global warming, the use of renewable energies is increasing day by day significantly. A considerable amount of electricity is generated from renewable energy sources since the last decade. Among the potential renewable energies, photovoltaic (PV) has experienced enormous growth in electricity generation. A large number of PV systems have been installed in on-grid and off-grid systems in the last few years. The number of PV systems will increase rapidly in the future due to the policies of the government and international organizations, and the advantages of PV technology. However, the variability of PV power generation creates different negative impacts on the electric grid system, such as the stability, reliability, and planning of the operation, aside from the economic benefits. Therefore, accurate forecasting of PV power generation is significantly important to stabilize and secure grid operation and promote large-scale PV power integration. A good number of research has been conducted to forecast PV power generation in different perspectives. This paper made a comprehensive and systematic review of the direct forecasting of PV power generation. The importance of the correlation of the input-output data and the preprocessing of model input data are discussed. This review covers the performance analysis of several PV power forecasting models based on different classifications. The critical analysis of recent works, including statistical and machine-learning models based on historical data, is also presented. Moreover, the strengths and weaknesses of the different forecasting models, including hybrid models, and performance matrices in evaluating the forecasting model, are considered in this research. In addition, the potential benefits of model optimization are also discussed.
626 citations
TL;DR: Current understanding of plant spectral properties with respect to sources of uncertainty at leaf to canopy scales is reviewed and a pattern that emerges suggests a synergy among the scattering effects of leaf-, stem- and canopy-level traits that becomes most apparent in the near-infrared (NIR) region.
Abstract: How plants interact with sunlight is central to the existence of life and provides a window to the functioning of ecosystems. Although the basic properties of leaf spectra have been known for decades, interpreting canopy-level spectra is more challenging because leaf-level effects are complicated by a host of stem- and canopy-level traits. Progress has been made through empirical analyses and models, although both methods have been hampered by a series of persistent challenges. Here, I review current understanding of plant spectral properties with respect to sources of uncertainty at leaf to canopy scales. I also discuss the role of evolutionary convergence in plant functioning and the difficulty of identifying individual properties among a suite of interrelated traits. A pattern that emerges suggests a synergy among the scattering effects of leaf-, stem- and canopy-level traits that becomes most apparent in the near-infrared (NIR) region. This explains the widespread and well-known importance of the NIR region in vegetation remote sensing, but presents an interesting paradox that has yet to be fully explored: that we can often gain more insight about the functioning of plants by examining wavelengths that are not used in photosynthesis than by examining those that are.
571 citations
Cites background from "The sun's total and spectral irradi..."
...1 (a) The solar radiation spectrum above and below the atmosphere, and (b) typical reflectance spectra of ( ) crop, ( ) tree and ( ) soil surfaces (Gueymard, 2004)....
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TL;DR: In this paper, the impact of dust accumulation, humidity level and air velocity on the performance of photovoltaic cells was investigated and the authors concluded that in order to have a profound insight of solar cell design, the effect of these factors should be taken into consideration in parallel.
Abstract: The environmental and economical merits of converting solar energy into electricity via photovoltaic cells have caused an ever increasing interest among developed and developing countries to allocate more budget on photovoltaic systems in order to boost up their efficiency in recent years. Besides the material and design parameters, there are several omnipresent factors such as dust, humidity and air velocity that can influence the PV cell's performance. There have been a handful of studies conducted on the effect of various influential parameters on the efficiency and performance of photovoltaic cells; however none has taken all these three parameters into account simultaneously. In this study the impact of dust accumulation, humidity level and the air velocity will be elaborated separately and finally the impact of each on the other will be clarified. It is shown that each of these three factors affect the other two and it is concluded that in order to have a profound insight of solar cell design, the effect of these factors should be taken into consideration in parallel.
519 citations
Cites background from "The sun's total and spectral irradi..."
...[1] Gueymard CA....
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...Sun acts like a black body radiator with the surface temperature of 5800 K which leads to a 1367 W/m2 energy density over the atmosphere [1–3]....
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References
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TL;DR: In this paper, a simple model for calculating direct normal and diffuse horizontal spectral solar irradiance for cloudless sky conditions was described. But the model was developed using rigorous radiative transfer codes and limited outdoor measurements.
Abstract: In a previous work, we described a simple model for calculating direct normal and diffuse horizontal spectral solar irradiance for cloudless sky conditions. In this paper, we present a new simple model (SPCTRAL2) that incorporates improvements to the simple model approach and an algorithm for calculating spectral irradiance on tilted surfaces. The model was developed using comparisons with rigorous radiative transfer codes and limited outdoor measurements. SPCTRAL2 produces terrestrial spectra between 0.3 and 4.0 μm with a resolution of approximately 10 nm. Inputs to the model include the solar zenith angle, the collector tilt angle, atmospheric turbidity, the amount of precipitable water vapor and ozone, surface pressure, and ground albedo. A major goal of this work is to provide researchers with the capability to calculate spectral irradiance for different atmospheric conditions and different solar collector geometries using microcomputers.
817 citations
TL;DR: In this paper, the authors presented a merging of the absolute integrals of the disk-center intensity for 20 A wide spectral bands and the ratios of mean to central intensity derived from recent observations of the center-to-limb variation of those bands (λ 6600 A).
Abstract: Results are presented, which follow from the merging of: (a) our previously published absolute integrals of the disk-center intensity for 20 A wide spectral bands; (b) the ratios of mean to central intensity derived from recent observations of the center-to-limb variation of those bands (λ 6600 A); (d) the high resolution Fourier transform spectra obtained by J. Brault at Kitt Peak for the disk-center and the irradiance; (e) some further auxiliary data, which served mainly to eliminate the local perturbations caused by lines of telluric molecular bands. The main result is the presentation of high precision radiation data for both the integrated disk and the disk-center, concerning the line-averaged radiation and the continuum (in UV: highest ‘window’-intensities) as well. The internal accuracy (the ‘scatter’) should not be worse than that of the FTS spectra, which is less than 0.2% (mean error); local systematic deviations exceeding 0.5% are not to be expected. The absence of a significant systematic error - neutral or wavelength-dependent - has been proven already elsewhere.
815 citations
TL;DR: In this article, an upgraded spectral radiation model called SMARTS2 (Simple Model of the Atmospheric Radiative Transfer of Sunshine) is introduced, based on spectral transmittance functions for the main extinction processes in the cloudless atmosphere: Rayleigh scattering, aerosol extinction, and absorption by ozone, uniformly mixed gases, water vapor, and nitrogen dioxide.
745 citations