Amount Of Solar Radiation Research Articles

The ecological niche of Echinococcus multilocularis in North America: understanding biotic and abiotic determinants of parasite distribution with new records in New Mexico and Maryland, United States

Understanding the factors shaping the niche of parasites and its expression over geographical space and through time continues to be a modern scientific challenge with the results of research in this area directly influencing both theoretical and applied biology. This is especially important for proactive management of zoonotic parasites such as Echinococcus multilocularis, the etiologic agent of alveolar echinococcosis. Echinococcus multilocularis has a Holarctic distribution; with its geographic range and prevalence increasing recently in areas of the western Palearctic, while its distribution dynamics are poorly understood in the Nearctic. In this paper, we use an ecological niche modeling (ENM) approach to: i) estimate the current spatial distribution of suitable conditions for the parasite in the Nearctic. ii) Evaluate the abiotic and biotic factors influencing the species distribution. iii) Assess the potential impact of climatic change on the distribution of this species in the Nearctic. Additionally, we report two new occurrence records of this parasite that significantly expands its known geographic range. We reviewed the occurrence records of E. multilocularis for the Nearctic. This was complemented by two new records of the species from Maryland and New Mexico identified using morphology and multivariate morphometrics of the rostellar hooks. From these data we created two ENMs using the software Maxent. The first ENM included climatic variables, while the second included the same abiotic data plus biotic information consisting of four host community-related data sets. We evaluated model performance and variable importance to explore the relation of these variables to the parasite niche. Finally, we projected the resulting niche model onto future climate change scenarios. We found that an important portion of the Nearctic has suitable conditions for E. multilocularis with adequate habitat in the West and East of the continent where the parasite has not been detected. We also found that the proposed biotic variables improve the model performance and provide unique information, while the most critical abiotic variable was related to the amount of solar radiation. Finally, under the future emission scenarios explored, the distribution of suitable habitat for the parasite is predicted to increase by 56 % to 76 %. We obtained a robust model that provides detail on the distribution of suitable areas for E. multilocularis, including areas that have not been explored for the presence of the parasite. The host community variables included in this study seem a promising way to include biotic data for ecological parasite niche modeling.

異なる追肥または遮光条件下で生育したパン用コムギ「せときらら」におけるリモートセンシングによる子実タンパク質含有率の予測

異なる追肥または遮光条件下で生育したパン用コムギ「せときらら」におけるリモートセンシングによる子実タンパク質含有率の予測

Arabica coffee fruits phenology assessed through degree days, precipitation, and solar radiation exposure on a daily basis.

Knowledge regarding reproductive cycle duration is important in terms of scheduling harvests and estimating coffee cultivars adaptability. Nine Coffea arabica cultivars were evaluated during two successive reproductive cycles. Dates of occurrence of the major blossoms, and the green and ripe fruits, on 64 branches for each cultivar, were registered during each reproductive cycle. These dates were used to calculate the duration of the fruit development (blossom to green) and ripening (green to ripe) phases, the quantities of degree days, precipitation, and solar radiation accumulated throughout each phase, and also degree days, precipitation, and radiation on a daily basis, all of which are novelties in coffee research. The differences between cultivars and reproductive cycles were tested by ANOVA. Cultivars were grouped in clusters according to the above-cited variables. Principally, the daily quantities of degree days and precipitation determined the differences between reproductive cycles and coffee cultivars during development phases. Early and very early cultivars accumulated high numbers of degree days.day-1, in periods of relatively good water availability, with high exposure to solar radiation. Late cultivars accumulated less degree days.day-1 and were exposed to lower amounts of daily solar radiation and longer periods of water scarcity. Regarding the fruit ripening phase, cultivars were principally distinguished by degree days and solar radiation on a daily basis. Two of the coffee cultivars were classified or confirmed as early and very early and another three as late and very late. One cultivar, Siriema, displayed an interesting conjugation of early and intermediate characteristics.

Reassessment of different antireflection coatings for crystalline silicon solar cell in view of their passive radiative cooling properties

In outdoor condition, the performance of the commercial solar photovoltaic (PV) modules depends on various parameters like (1) amount of direct solar radiation, (2) ambient temperature, (3) the location of installation, (4) wind speed, (6) aerosol, and most of these parameters are uncontrollable. The first two of these parameters increase the solar cell operating temperature which in turn decreases the performance of the solar cell. This simulation-based study presents the development of a passive radiative cooling system for a simple flat crystalline silicon (c-Si) solar cell using a thin film of SiO2, Al2O3, Si3N4, HfO2 or TiO2. Some of these materials are being used as an antireflection coating (ARC) in the commercial solar panel for having a suitable refractive index (n) and very low extinction coefficient (k) values in 300–1200 nm wavelength range. In the 8–13 µm wavelength range, the variation of emissivity of the materials w.r.t. thickness and angle have been calculated. The thickness of ARC, the absorptivity of Silicon, the emissivity of ARC in the atmospheric window was also estimated. Suitable ARC cum emissive layer helps the solar cell in absorptivity improvement as well as keeping its temperature near the ambient temperature. The present study finds that Si3N4 is having a higher emissive power than the other materials and increases (10–161.63 W m−2) with the increase in thickness from 20 to 1000 nm in 8–13 µm wavelength range. Material like SiO2 and Al2O3 have emissivity lower than Si3N4 of comparable thickness.

Numerical Simulation of Tracking Modes for Compound Parabolic Collector With Tubular Receiver

Correct placement of solar collectors is one of the important parameters for maximum utilization of heat radiated by the sun. Compound parabolic collector (CPC) with low acceptance angle needs frequent tracking to collect the maximum amount of solar radiation. The number of tracking depends on the location of CPC with respect to the sun position throughout a day. This study is executed to investigate the amount of solar incident flux falls on the reflector of the CPC by the implementation of five different tracking modes. The numerical analysis is performed on CPC geometry with the 50 number of possible orientations for five tracking modes and 10 h. These results are compared with theoretical results for validation purpose. It is observed that mode 3, mode 4, and mode 5 give more solar heat flux but offers more complexity in mounting and tracking as is compared to mode 1 and mode 2. Also, the shading effect of receiver tube on the heat flux distribution is presented which would reduce the optical efficiency.

Investigation of optimal tilt angles and effects of soiling on PV energy production in Pakistan

Tilt angle of photovoltaic (PV) panel strongly contributes to the amount of solar radiation harvested by the PV panel. In this paper, we model the optimal PV tilt angle for Lahore and some of the other major cities in Pakistan using the available solar radiation data from NREL and ESMAP. The model is used to propose an optimal schedule for PV tilt in Lahore involving four adjustments in a year that can provide ∼6.6% increase in the yearly energy generation relative to a fixed tilt. The model is validated with PV tilt experiments. Moreover, a simple model is developed to estimate the upper/lower bounds of soiling losses in Lahore using the reported distributions for aerosol particulates. We show that the power loss due to soiling could be up to 10% for a lightly soiled panel and could go up to 40% for a heavily soiled panel. We further explore the tilt angle effect on the soiling losses in Lahore by doing soiling experiments. For a period of 100 days, dust deposition on a horizontal panel results in 26.2% energy loss as compared to a clean panel. For the same period, the corresponding loss for a vertical tilt was 13.5%. The variability of soiling effects with respect to tilt is used to predict an optimal tilt angle when the soiling losses are significant. These findings provide important insights into the protocols of tilt adjustments in presence of environmental dust for PV systems in Pakistan and further highlight the significance of soiling losses for the typical aerosol conditions in Lahore.

Model selection for accurate daily global solar radiation prediction in China

Solar energy can share with a big percentage in solving in the environmental pollution and energy crisis in China. For the most application of solar energy, an accurate information of solar radiation amount received by a horizontal surface is the first step. In this study, nine-day of the year based models are calibrated and evaluated to estimate the daily global solar radiation (DGSR) on a horizontal surface using long-term data of 84 stations all over China. After dividing China into five solar climatic zones, the highest performance model for each zone is chosen to be a general day of the year based models and then calibrate and evaluated at each solar zone. Based on statistical indicator; the root mean square error (RMSE), the mean absolute bias error (MABE), coefficient of determination (R2) and the correlation coefficient (r) and the uncertainty based on a 95% confidence level (U95) and Taylor diagram, results show that the models perform best in the solar zones that receive a high amount of solar radiation and the performance decreases with decreasing of the daily solar radiation incidence. The hybrid sine and cosine wave day of the year based models exhibit the best performance, model D7 is the best for zone I and model D8 for zones II and IV. For zones II and V, the Gaussian form model (D3 model) and the 4th order polynomial model (D4 model) yield high performance, respectively. Whereas, the two Gaussian form model is the worth performance for all zones. The developed general day of the year based models for each zone in this study can be used with high accuracy to estimate the (DGSR) on a horizontal surface in areas where there is no data or the data is missing all over China.

Evaluation of a novel greenhouse design for reduced cooling loads during the hot season in subtropical regions

Greenhouses provide an optimized growth environment for plants. However, providing this environment is energy intensive. In subtropical regions, most of this energy is to cater for the required cooling. The cooling demand is mainly attributed to the entry of excess solar radiation and heat gain through the greenhouse walls. This study proposes a thermally insulated greenhouse that allows the entry of optimum solar radiation levels through negative linear Fresnel lenses located in its roof. The lenses distribute the solar radiation over the plant rows. The performance of the proposed greenhouse in terms of providing the required levels of solar radiation for plant growth and the reduction in cooling load were assessed using ray tracing simulations and cooling load calculations. The results showed that the recommended optimum amount of solar radiation required for tomato growth can be achieved during the hot season inside the proposed greenhouse. In comparison to a conventional greenhouse, the monthly cooling load of the proposed greenhouse was about 80% less. Therefore, the proposed greenhouse can achieve the benefits of a closed greenhouse while overcoming the high cooling demand drawback, in subtropical regions.

The role of low-level clouds in the West African monsoon system

Abstract. Realistically simulating the West African monsoon system still poses a substantial challenge to state-of-the-art weather and climate models. One particular issue is the representation of the extensive and persistent low-level clouds over southern West Africa (SWA) during boreal summer. These clouds are important in regulating the amount of solar radiation reaching the surface, but their role in the local energy balance and the overall monsoon system has never been assessed. Based on sensitivity experiments using the ICON model for July 2006, we show for the first time that rainfall over SWA depends logarithmically on the optical thickness of low clouds, as these control the diurnal evolution of the planetary boundary layer, vertical stability and finally convection. In our experiments, the increased precipitation over SWA has a small direct effect on the downstream Sahel, as higher temperatures due to increased surface radiation are accompanied by decreases in low-level moisture due to changes in advection, leading to almost unchanged equivalent potential temperatures in the Sahel. A systematic comparison of simulations with and without convective parameterization reveals agreement in the direction of the precipitation signal but larger sensitivity for explicit convection. For parameterized convection the main rainband is too far south and the diurnal cycle shows signs of unrealistic vertical mixing, leading to a positive feedback on low clouds. The results demonstrate that relatively minor errors, variations or trends in low-level cloudiness over SWA can have substantial impacts on precipitation. Similarly, they suggest that the dimming likely associated with an increase in anthropogenic emissions in the future would lead to a decrease in summer rainfall in the densely populated Guinea coastal area. Future work should investigate longer-term effects of the misrepresentation of low clouds in climate models, e.g. moderated through effects on rainfall, soil moisture and evaporation.

Smart Grid Privacy Protection Using Solar Energy and Rechargeable Battery

In smart grid, smart meter (SM) samples users’ energy consumption at high frequency. By analyzing the fine-grained smart metering data, users’ behavior patterns can be recognized thus threatening consumers’ privacy. In this paper, the protection of SM privacy is studied in the presence of solar energy generation system and a rechargeable battery (RB). Solar energy plays the role of an alternative electricity provider for users except power grid. RB can be used to partially hide the real appliance consumption while cut down the electricity bills. A “privacy safe-cost friendly optimal model” is developed aimed at minimizing the weighted sum of privacy leakage and financial cost, with constraints of battery physical conditions and solar radiation amount. In order to solve the optimal problem, we formulate a novel inner-outer optimal algorithm. Simulations demonstrate the efficacy of the proposed algorithm using real data. The impact of the battery capacity and the amount of solar energy on the privacy protection is also studied.

Photovoltaic Production Possibilities and its Utilization in Office Buildings in Finland

Photovoltaic electricity production data was gathered during a one year period in southern Finland (Espoo, 60.11°N, 24.49°E) from each principal compass point and using several tilt angles in the south facing solar panel. The results showed that the amount of produced electricity and the optimum tilt angle of the solar panels vary greatly in this location according to the time of year. Photovoltaic production data was further applied to office equipment consumption calculations and as a result required solar panel area for each office device was calculated. Calculations were done for the least and the most consuming devices of each group. Conclusion was that the selection of office devices affects greatly to the required solar panel area, as well as to the yearly electricity bill if the electricity is bought from the grid. After this these calculated results were applied to a different geographical location that receives much more sunlight. The selected location for this comparison was Khartoum in Sudan (15.5°N, 32.5°E). Comparison between Sudan and Finland was realized using the statistical solar radiation data of NASA Surface Meteorology and Solar Energy Database and the field measurements performed in the Lighting Unit of Aalto University, Espoo in Finland. This comparison showed that during December, which is the least sunniest month in Finland, the required solar panel area in Finland was 10 times larger than the required area in Sudan. In the summer the solar radiation amounts of these two locations are more equivalent and the required solar panel area is only 1,3 times larger in Finland than in Sudan.

A comparative study of P&O and INC maximum power point tracking techniques for grid-connected PV systems

The electrical demand is quickly increased, and renewable energy sources are an indispensable need for supporting the electric grid and supplying the isolated loads. Renewable energy is found in numerous forms like solar energy, wind energy, tidal energy. Solar power system is clean, and large amounts of solar radiation arrive to the surface of the earth. This paper aims to maximize the amount of extracted electrical power from the solar energy system. This work investigates in detail the concept of MPPT techniques which significantly increase the efficiency of the solar PV system. This paper presents a simulation-based comparative study between two most common algorithms, perturb and observe and incremental conductance techniques, to optimize the energy conversion efficiency of PV system. Simulation analysis and results of the PV module are made to get its characteristics.

Experimental comparison of green facades with outdoor test cells during a hot humid season

We used outdoor test cells during a hot humid period to analyse the surface temperatures behind the following four types of green walls: a felt layer wall; a planter boxes wall; a direct climbing plants wall, and; an indirect climbing plants wall. We compared these temperatures with temperatures of a bare wall and we found that all four types of green facades were able to maintain lower temperatures than the bare wall, and that the felt layer and planter boxes wall had lower temperatures than the other walls for the majority of the study period. In particular, the daily average and peak surface temperatures behind the felt layer wall were by 1.9 °C–4.8 °C and by 7.1 °C–13.4 °C respectively lower than the bare wall. We undertook a significance analysis and produced Pearson coefficients to better understand the relationship between average daily weather conditions and the surface temperatures on all five test cells. We noted that the average daily solar radiation flux did not affect the surface temperatures behind the planter boxes and felt layer walls, but the daily average ambient air temperature was significantly correlated with the average and peak surface temperatures behind all four green facades. Finally, we concluded that the cooling potential of the felt layer and the planter boxes walls increases with higher amounts of solar radiation and higher ambient temperatures. In addition, from the analysis of the diurnal temperature variations and the time series trends we illustrated that the temperatures behind the felt layer and planter boxes walls fluctuated less than the other walls, which lead to a slower rate of surface temperature reductions during a cooler day than the other wall types of the study.

MODELING STUDY OF PV POWER PLANTS IN DIFFERENT IRAQ’S GOVERNORATES

The available huge amount of solar radiation in Iraq all over the year can be regarded as a useful energy source. It can be utilized to generate electrical energy using PV panel’s power plants. Therefore, it is important to recognize the behavior of these PV Panels through the year with changing in amount of the solar radiation and weather temperature. The monthly average (daily and hourly) of extraterrestrial, global, diffused, and beam radiation, with PV panel’s temperature and electrical efficiency of different tilt angle is studied in three Iraqi’s cities. The results indicated that the total radiation ranges are greater in Karbala than Samarra and Basra cities; despite of the extraterrestrial radiation in Basra higher value than Samarra and Karbala cities. The higher magnitude in the monthly average solar radiation in any city is not necessarily best location for construction PV power plant, because the electrical performance of PV panels is affected by its temperature. Rising in temperature led to drop in the PV panel’s efficiency.

A standalone BLDC based solar air cooler with MPP tracking for improved efficiency

This article proposes the idea of using Solar Energy (SE) as a source of power for designing and developing a standalone air-cooling system. This type of application is particularly suited for rural areas that have a considerable amount of solar radiation and have no access to grid systems. The proposed system is comprised of a photovoltaic (PV) array, DC-DC boost converter and DC-DC buck converter. Two Permanent Magnet Brushless Direct Current (PMBLDC) motors are employed to drive a centrifugal water pump and an air blower coupled to their individual shafts. The air blower is connected with a DCDC boost converter that ensures a maximum power point (MPP) operation. A centrifugal water pump is connected with a DC-DC buck converter. The challenging task in an air cooling system is to maintain the constant speed of the blower under variable irradiance conditions. The power provided by the solar PV array can be shared between the two DC-DC converters in such a way that the BLDC motor connected with the blower will maintain a constant speed by maintaining the constant voltage of the DCDC boost converter. The rest of the available PV power will be handled by the pump. The suitability of the proposed system for various perturbations is evaluated by simulating the proposed system using a MATLAB/Simulink and is validated by conducting experiments. Case studies have been performed with a variable PV irradiance and the results are explored.

Experimental performance analysis of a multiple-source and multiple-use heat pump system: winter field experiment and heating operation performance evaluation

We herein report the development of a distributed heat pump system that can utilize a variety of renewable energy sources to meet different building heating and cooling demands (i.e., a multiple source and multiple use heat pump system, MMHP). In this system, a water circulating loop is used to connect ground heat exchangers, a unique sky-source heat pump, and various heat pumps for heating and cooling purposes to form a thermal network within a building. This distribution increases the flexibility of the system and allows an improved matching of supply and demand. To evaluate the system performance, an experimental house was constructed, and a winter field experiment was conducted. We found that the reported heat pump for floor heating achieved a stable operation with a high coefficient of performance of ~11.5, while the heat collecting operation performance of the sky-source heat pump varied significantly depending on the amount of solar radiation and the outside air temperature. Finally, since the sky-source heat pump contributes to an improvement in the whole system performance, it appears that there is still room for improved regarding the whole system performance by adjusting the operating and control strategy.

The possibility of use of solar energy in the southeastern part of Western Siberia

The article presents the results of a study of the regime of solar radiation in the southeastern part of Western Siberia. To characterize the regime of solar radiation, long-term observational data on actinometrical and meteorological stations were used. The dependence of the total annual global radiation on latitude received. The dependence of the sunshine duration on latitude it gives. The potential amount of total solar radiation per year under average conditions cloud cover and atmospheric transparency considered. Common regularities of solar radiation arriving to the slopes of varying steepness and exposure can be distinguished in mountainous areas. On the basis of the potential arriving of the total solar radiation in the southern part of Western Siberia we can distinguish three latitude zones.

Analysis of photovoltaic system with battery storage in winter period

Energy sources as a solar, wind and water energy are used in production of electrical energy. Their biggest advantage is that they are renewable and they are sustainable. On the other hand, production from renewable energy sources is limited by environmental conditions. Production of photovoltaic systems are dependent on solar radiation, temperature, incidence angle, shadowing and other variable quantities. That is why designing of photovoltaic system is complex. In this paper a photovoltaic system production analysis and consumption analysis in residential house are presented. With real measured data the consumption and production are compared and energy balance equations, battery charge and discharge model are defined and behaviour of battery storage system through the one day are analysed. In addition, the reactive energy production and consumption are also analysed.

Environmental Effects on the Performance of Polycrystalline Silicon Solar Cells under Long-Term Outdoor Exposure in Taiyuan, China

Environmental conditions such as wind, temperature and humidity affect the amount of solar irradiance received by the photovoltaic (PV) cells and thus have a significant effect on the PV output efficiency. This paper aims to analyze the power efficiency of Polycrystalline Silicon solar cells under China’s weather considering these environmental conditions. Performance of the Polycrystalline solar panel is analyzed through eight months of data emphasizing the maximum, average and minimum temperature acquired from a solar power plant installed at Taiyuan University of technology, China consisting of 78 PV panels with a total rated capacity of 20 KW and average module efficiency of 16.56% at an ambient temperature of 25°. The results of our practical investigations show that polycrystalline solar cells in October yield the best monthly average efficiency of 35.6% at an average temperature and humidity level of 14°C and 44%. In comparison to a maximum temperature of 27°C and humidity of 66% in summer, the efficiency is found to drop by 5%. Also, the power produced in winter at minimum temperature and the efficiency showed a decline of 15% compared to that of October. Consequently, this investigation leads to a conclusion that the increase in temperature and humidity together is found to have a negative effect on the efficiency whereas the increase in irradiance and wind speed showed an improvement in the output power of the polycrystalline solar cells.

Forecasting of Solar Irradiance using Probability Distributions for a PV System: A Case Study

Photo Voltaic (PV) generation is intermittent which cannot carry out the constant electric power. The amount of solar irradiance received for a particular area is one of the most important climatic conditions for forecasting PV generation. The solar irradiance data used for analysis is collected from Koneru Lakshmaiah Education Foundation (KLEF) and the data is collected for the year (2017-18). In this paper, four Probability Distribution Functions (PDFs) such as Normal, Weibull, Rayleigh, Log normal are used to investigate the best fit probability distribution of the collected solar irradiance data. Root Mean Square Error (RMSE) method is used as a goodness of fit test for identifying the best suited probability distribution function for the collected solar irradiance data. With this analysis, solar irradiance and PV power generation can be predicted for the next year. The efficacy of the proposed method is validated using MATLAB.