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Solmap: Project In India's Solar Resource Assessment
摘要： India launched Jawaharlal Nehru National Solar Mission in 2009, which aims to set up 20 000 MW of grid connected solar power, besides 2 000 MW equivalent of off-grid applications and cumulative growth of solar thermal collector area to 20 million m2 by 2022. Availability of reliable and accurate solar radiation data is crucial to achieve the targets. As a result of this initiative, Ministry of New and Renewable Energy (MNRE) of Government of India (GoI) has awarded a project to Centre for Wind Energy Technology (C-WET), Chennai in the year 2011 to set up 51 Solar Radiation Resource Assessment (SRRA) stations using the state-of-the-art equipment in various parts of the country, especially the sites with high potential for solar power. The GoI project has synergy with SolMap project, which is implemented by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) in cooperation with the MNRE. SolMap project is contributing to SRRA project in establishing quality checks on the data obtained as per International protocols and helping data processing to generate investment grade data. The paper highlights the details of SRRA stations and an attempt has been made to present some of the important results of quality control and data analysis with respect to GHI and DNI. While our analysis of the data over one year finds that intensity and profile of the insolation are not uniform across the geographic regions, the variability in DNI is particularly high. Strong influence of monsoon is also identified. SRRA infrastructure aims to develop investment grade solar radiation resource information to assist project activities under the National Solar Mission of India.
关键词： DNI,solar radiation,pyrheliometer,GHI,resource assessment,India
更新于2025-09-23 15:22:29
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Directional Statistics in Solar Potential of Rooftops at Three Different Neighborhoods of a Medium Size City
摘要： The utilization of solar energy is one of the best effective methods to combat the climate change. The estimation of solar potential in urban areas can vary depending on the urban morphology. This paper performs a directional statistical analysis of the distribution of the monthly solar potential of rooftops in Cáceres city, related to the orientation of the rooftops in different neighborhoods. The orientation values of the roofs will be treated as a directional data and the radiation values as a linear data. The circular graphics representing the orientation data is a suitable representation of the distribution of the buildings being related with the urban framework.
关键词： rooftop orientation,directional data,solar potential,solar radiation
更新于2025-09-23 15:21:21
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Proximal remote sensing of tree physiology at northern treeline: Do late-season changes in the photochemical reflectance index (PRI) respond to climate or photoperiod?
摘要： Relatively little is known of how the world's largest vegetation transition zone – the Forest Tundra Ecotone (FTE) – is responding to climate change. Newly available, satellite-derived time-series of the photochemical reflectance index (PRI) across North America and Europe could provide new insights into the physiological response of evergreen trees to climate change by tracking changes in foliar pigment pools that have been linked to photosynthetic phenology. However, before implementing these data for such purpose at these evergreen dominated systems, it is important to increase our understanding of the fine scale mechanisms driving the connection between PRI and environmental conditions. The goal of this study is thus to gain a more mechanistic understanding of which environmental factors drive changes in PRI during late-season phenological transitions at the FTE – including factors that are susceptible to climate change (i.e., air- and soil-temperatures), and those that are not (photoperiod). We hypothesized that late-season phenological changes in foliar pigment pools captured by PRI are largely driven by photoperiod as opposed to less predictable drivers such as air temperature, complicating the utility of PRI time-series for understanding climate change effects on the FTE. Ground-based, time-series of PRI were acquired from individual trees in combination with meteorological variables and photoperiod information at six FTE sites in Alaska. A linear mixed-effects modeling approach was used to determine the significance (α = 0.001) and effect size (i.e., standardized slope b*) of environmental factors on late-seasonal changes in the PRI signal. Our results indicate that photoperiod had the strongest, significant effect on late-season changes in PRI (b* = 0.08, p < 0.001), but environmental variables susceptible to climate change were also significant (i.e., daily mean solar radiation (b* = ?0.03, p < 0.001) and daily mean soil temperature (b* = 0.02, p < 0.001)). These results suggest that interpreting PRI time-series of late-season phenological transitions may indeed facilitate our understanding of how northern treeline responds to climate change.
关键词： PRI,Climate change,Photoperiod,Photosynthetic phenology,MODIS,Solar radiation,Northern treeline,Forest Tundra Ecotone
更新于2025-09-23 15:21:21
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Study of solar irradiance and performance analysis of submerged monocrystalline and polycrystalline solar cells
摘要： Underwater photovoltaic (PV) systems supported with modern-day technology can lead to possible solutions for the lack of long-term power sources in marine electronics, navy corps, and many other remotely operated underwater power systems. Currently, most of these systems are powered by conventional batteries, which are bulky, costly, and require periodic maintenance and replacement. Harnessing the underwater Solar energy by using Solar PV cells is simple, reliable, and leads to tremendous advantageous as water itself provides cooling, cleaning, and avoid challenges due to land constraints. The present work encompasses an experimental study on Solar radiation in water and its changes with varying water conditions. Accordingly, the performance of monocrystalline and polycrystalline silicon solar cells with different submerged water conditions and water depths up to 20 cm has been studied. Most importantly, these studies have been carried out with different types of water conditions, consisting of salinity, bacteria, algae, and other water impurities. These investigation results manifest that the percentage decrease of maximum power output in monocrystalline and polycrystalline Solar cells is 65.85% and 62.55%, respectively, in the case of ocean water conditions, whereas in deionized (DI) water conditions, it is 63.06% and 60.72% up to 20 cm. Such results conclude that valuable amount of Solar energy is can be explored underwater. These experimental studies pave the way to explore further to utilize Solar PV cells efficiently in underwater conditions.
关键词： monocrystalline Solar cell,underwater Solar radiation,photovoltaic (PV) technology,PDMS (polydimethylsiloxane),water salinity,polycrystalline Solar cell
更新于2025-09-23 15:21:01
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Cloudiness and solar radiation during the longest total solar eclipse of the 21st century at Tianhuangping (Zhejiang), China
摘要： The lack of comprehensive solar radiation monitoring during the longest total solar eclipse (TSE) of the 21st century at Tianhuangping (Zhejiang), China, on July 22, 2009, has led to this investigation in order to evaluate the cloudiness contribution in estimating the impact on global solar radiation throughout this phenomenon. In doing so, we applied a cloud-cover empirical model to obtain the global solar radiation and, at the same time, we deduced a theoretical model to get the direct solar radiation in which both the occultation and obscuration function of this eclipse are included. We took limb-darkening and atmospheric transmission into account. Though the weather during our eclipse observations agreed with the forecasts for that day: clouds and some rain, we were nonetheless able to observe all phases of the eclipse from our observation site at Tianhuangping. This experience suggests that for coming eclipses a record of the in situ observation protocol of cloudiness is mandatory. Our results for comparing global solar radiation models, indicate that our TSE radiation model is quite acceptable and representative of that which could have happened at that time.
关键词： Moon,cloudy skies,China eclipse,solar radiation,Sun,occultation,obscuration
更新于2025-09-23 15:21:01
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Performance evaluation of existing sunshine-based computing models for estimating global solar radiation at Lagos, Nigeria
摘要： Several empirical models have been fitted in literature for estimating global solar radiation across the globe in order to produce global solar radiation data and also as a baseline for further scientific and environmental research without the substantial cost of instrumental network that would otherwise be needed. However, peers and researchers have reported that the most commonly employed parameter for predicting global solar radiation is sunshine duration as a result of its availability and simplicity in course of measurement globally. In this research, the author considered the performance of 63 sunshine-based models for the prediction of global solar radiation at Lagos, Nigeria. Numerous models are found unreliable for use in this location, and others vary in performance. On the whole, the best model was identified due to its values of statistical indicators.
关键词： Global Solar Radiation,Tropical Rainforest Zone,Sunshine Based Models,Lagos,Statistical Indicators
更新于2025-09-23 15:21:01
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Benchmarking on improvement and site-adaptation techniques for modeled solar radiation datasets
摘要： High-accuracy solar radiation data are needed in almost every solar energy project for bankability. Time series of solar irradiance components that spans decades can be supplied by satellite-derived irradiance or by reanalysis models, with very various types of uncertainty associated to the speci?c approaches taken and quality of boundary conditions information. In order to improve the reliability of these modeled datasets, comparison with ground measurements over a short period of time can be used for correcting some aspects, bias mainly, of the modeled data by using di?erent methodologies; this procedure is known as site adaptation. Therefore, a benchmarking exercise that uses di?erent site adaptation techniques was proposed within the Task 16 IEA-PVPS activities. In this work, over ten di?erent site-adaptation techniques have been used for assessing the accuracy improvement, using ten di?erent datasets covering both satellite-derived and reanalysis solar radiation data. The e?ectiveness of these methods is found not universal or spatially homogeneous, but in general, it can be stated that signi?cant improvements can be achieved eventually in most sites and datasets.
关键词： Bankability of data for solar projects,Site adaptation,Modeled solar radiation data,Satellite-derived solar radiation
更新于2025-09-23 15:19:57
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IPR 1.0: an efficient method for calculating solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities
摘要： Climate change may alter the spatial distribution, composition, structure and functions of plant communities. Transitional zones between biomes, or ecotones, are particularly sensitive to climate change. Ecotones are usually heterogeneous with sparse trees. The dynamics of ecotones are mainly determined by the growth and competition of individual plants in the communities. Therefore it is necessary to calculate the solar radiation absorbed by individual plants in order to understand and predict their responses to climate change. In this study, we developed an individual plant radiation model, IPR (version 1.0), to calculate solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities. The model is developed based on geometrical optical relationships assuming that crowns of woody plants are rectangular boxes with uniform leaf area density. The model calculates the fractions of sunlit and shaded leaf classes and the solar radiation absorbed by each class, including direct radiation from the sun, diffuse radiation from the sky, and scattered radiation from the plant community. The solar radiation received on the ground is also calculated. We tested the model by comparing with the results of random distribution of plants. The tests show that the model results are very close to the averages of the random distributions. This model is ef?cient in computation, and can be included in vegetation models to simulate long-term transient responses of plant communities to climate change. The code and a user’s manual are provided as Supplement of the paper.
关键词： climate change,individual plant radiation model,solar radiation,ecotones,vegetation models,IPR
更新于2025-09-23 15:19:57
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Analysing consequence of solar irradiance on amorphous silicon solar cell in variable underwater environments
摘要： Harvesting underwater Solar energy using photovoltaic (PV) technology leads to an innovative approach to utilize it in monitoring various underwater sensors, devices, or other autonomous systems using modern-day power electronics. Another huge advantage of placing PV cells underwater comes from the fact that the water itself can provide cooling and cleaning for the cells. Such advantages come with many challenges and constraints due to the underwater spectral change and decrease in Solar radiation with an increase in water depth. In this work, an experimental set-up has been realized to create an underwater environment and further characterized in the indoor environment using the Solar simulator. Moreover, the transfer of Solar radiation through water and the performance of amorphous silicon Solar cell underwater up to 0.2 m has been analysed in changing underwater environments. This investigation shows a better understanding of solar radiation underwater and the amorphous silicon solar cell underwater at shallow depths with considering the water depth up to 0.2 m, salinity 3.5%, total dissolved salts, and other impurities affecting the solar radiation and the performance of amorphous silicon Solar cell in underwater conditions. In addition to that, the maximum power output Pmax of amorphous silicon Solar cell is 0.0367 W at 0.2 m in the case of DI water. In contrast, in real seawater and artificial seawater with 3.5% salinity, it shows 0.0337 W and 0.0327 W, respectively.
关键词： water salinity,amorphous silicon Solar cell,photovoltaic (PV) technology,underwater Solar energy,Solar radiation,PDMS (polydimethylsiloxane)
更新于2025-09-23 15:19:57
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Optimum Angle of Inclination for a Fixed Stand-Alone Photovoltaic: A Review
摘要： The optimum angle of tilt for PV system is very important for best performance in the generation of power and other related use of photovoltaic. This work, reviews the best angle of inclination for a stand-alone photovoltaic panel. The consideration of various studies has been looked at in line with some models. It was observed that the yearly fixed angle of tilt is close to or same as the latitude for a given location, although this may not be appropriate for use in other locations. The annual optimal angle of tilt of some locations were closely related in value i.e. 20.50o, 20.50o, 21.50o, 20.20o, 21.30o and 22.40o. The best electrical performance for the PV system was observed to be above 1598kWh/m2 at20o inclination facing south. Hencethe value of the optimum angle of tilt for best electrical performance of an array of stand-alone PV system could vary between 0o and 90o depending on the location latitude.
关键词： solar radiation,solar power,Photovoltaic,optimum angle of tilt
更新于2025-09-23 15:19:57