Using High Resolution Solar Measurement in PV Variability Studies

Author(s):  
Manajit Sengupta

Clouds, aerosols, water vapor and other atmospheric constituents influence solar energy reaching the earth’s surface. Each of these atmospheric constituents has it’s own inherent scale of temporal and spatial variability and they in turn influence the variability in the amount of solar radiation reaching the earth’s surface. This combined influence of the atmospheric constituents and their separate variability characteristics makes solar variability modeling a complicated task. Output from photovoltaic (PV) power plants is dependent on the amount of solar energy reaching the surface. Therefore variability in solar radiation results in variability in PV plant output. The issue of variability in PV plant output has become important in the last couple of years as utility scale PV plants go online and increase in size. Understanding variability in PV plant output requires an understanding of (a) the spatial and temporal variability of solar radiation; (b) the influence of this solar variability on PV plant output. The goal of this paper is to understand what temporal and spatial scales of variability in Global Horizontal Radiation (GHI) are important to a PV plants and what measurements are needed to be able to characterize them. As solar radiation measuring instruments are point receivers it is important to understand how those measurements translate to energy received over a larger spatial extent. Also of importance is the temporal nature of variability characterized not at a single point on the ground but over large spatial areas. In this research we use high temporal and spatial resolution measurements from multiple time synchronized solar radiation sensors to create solar radiation fields at various spatial and temporal scales using a wide range of interpolation techniques. These solar fields are then used to create plant power output for various size PV plants. As various interpolation schemes can produce different distributions we investigate the impact of interpolation schemes on GHI and power output distribution. While power output from PV plants is an important quantity the temporal variability of power is a matter of concern to utilities. In this paper we show how PV plant output varies across different time scales.

2019 ◽  
Vol 56 (1) ◽  
pp. 261-270
Author(s):  
Maria Stoicanescu ◽  
Aurel Crisan ◽  
Ioan Milosan ◽  
Mihai Alin Pop ◽  
Jose Rodriguez Garcia ◽  
...  

This paper presents and discusses research conducted with the purpose of developing the use of solar energy in the heat treatment of steels. For this, a vertical axis solar furnace called at Plataforma Solar de Almeria was adapted such as to allow control of the heating and cooling processes of samples made from 1.1730 steel. Thus temperature variation in pre-set points of the heated samples could be monitored in correlation with the working parameters: the level of solar radiation and implicitly the energy used the conditions of sample exposed to solar radiation, and the various protections and cooling mediums.The recorded data allowed establishing the types of treatments applied for certain working conditions. The distribution of hardness, as the representative feature resulting from heat treatment, was analysed on all sides of the treated samples. In correlation with the time-temperature-transformation diagram of 1.1730 steel, the measured values confirmed the possibility of using solar energy in all types of heat treatment applied to this steel. In parallel the efficiency of using solar energy was analysed in comparison to the energy obtained by burning methane gas for the heat treatment for the same set of samples. The analysis considered energy consumption, productivity and the impact on the environment. Thanks to various data obtained through developed experiences, which cover a wide range of thermic treatments applied steels 1.1730 model, we can certainly state that this can be a solid base in using solar energy in applications of thermic treatment at a high industrial level.


2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.


2021 ◽  
Author(s):  
Blanka Bartok

<p>As solar energy share is showing a significant growth in the European electricity generation system, assessments regarding long-term variation of this variable related to climate change are becoming more and more relevant for this sector. Several studies analysed the impact of climate change on the solar energy sector in Europe (Jerez et al, 2015) finding light impact (-14%; +2%) in terms of mean surface solar radiation. The present study focuses on extreme values, namely on the distribution of low surface solar radiation (overcast situation) and high surface solar radiation (clear sky situation), since the frequencies of these situations have high impact on electricity generation.</p><p>The study considers 11 high-resolution (0.11 deg) bias-corrected climate projections from the EURO-CORDEX ensemble with 5 Global Climate Models (GCMs) downscaled by 6 Regional Climate Models (RCMs).</p><p>Changes in extreme surface solar radiation frequencies show different regional patterns over Europe.</p><p>The study also includes a case study determining the changes in solar power generation induced by the extreme situations.</p><p> </p><p> </p><p>Jerez et al (2015): The impact of climate change on photovoltaic power generation in Europe, Nature Communications 6(1):10014, 10.1038/ncomms10014</p><p> </p>


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Gerardo Andres Saenz ◽  
Huei-Ping Huang

The projected changes in the downward solar radiation at the surface over North America for late 21st century are deduced from global climate model simulations with greenhouse-gas (GHG) forcing. A robust trend is found in winter over the United States, which exhibits a simple pattern of a decrease of sunlight over Northern USA. and an increase of sunlight over Southern USA. This structure was identified in both the seasonal mean and the mean climatology at different times of the day. It is broadly consistent with the known poleward shift of storm tracks in winter in climate model simulations with GHG forcing. The centennial trend of the downward shortwave radiation at the surface in Northern USA. is on the order of 10% of the climatological value for the January monthly mean, and slightly over 10% at the time when it is midday in the United States. This indicates a nonnegligible influence of the GHG forcing on solar energy in the long term. Nevertheless, when dividing the 10% by a century, in the near term, the impact of the GHG forcing is relatively minor such that the estimate of solar power potential using present-day climatology will remain useful in the coming decades.


2021 ◽  
Author(s):  
Faiza Azam ◽  
Jethro Betcke ◽  
Marion Schroedter-Homscheidt ◽  
Mireille Lefevre ◽  
Yves-Marie Saint-Drenan ◽  
...  

<p>The Copernicus Atmospheric Monitoring Service (CAMS) offers Solar radiation services (CRS) providing information on surface solar irradiance (SSI). The service is currently derived from Meteosat Second Generation (MSG) and the service evolution includes its extension to other parts of the globe. CRS provides clear and all sky time series combining satellite data products with numerical model output from CAMS on aerosols, water vapour and ozone. These products are available from 2004 until yesterday. A regular quality control of input parameters, quarterly benchmarking against ground measurements and automatic consistency checks ensure the service quality.</p> <p>Variability of solar surface irradiances in the 1-minute range is of interest especially for solar energy applications. The variability classes can be defined based on ground as well as satellite-based measurements. This study will present the evaluation of the CAMS CRS based on the eight variability classes derived from ground observations of direct normal irradiation (DNI) (Schroedter-Homscheidt et al., 2018). Such an analysis will help assess the impact of recent improvements in the derivation of all sky irradiance under different cloudy conditions.</p> <p>References:</p> <p>Schroedter-Homscheidt, M., S. Jung, M. Kosmale, 2018: Classifying ground-measured 1 minute temporal variability within hourly intervals for direct normal irradiances. – Meteorol. Z. 27, 2, 160–179. DOI:10.1127/metz/2018/0875.</p>


Vehicles ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Partridge ◽  
Wu ◽  
Bucknall

This paper presents the development of a control strategy for a fuel cell and supercapacitor hybrid power system for application in a city driving bus. This aims to utilise a stable fuel cell power output during normal operation whilst allowing variations to the power output based on the supercapacitor state-of-charge. This provides flexibility to the operation of the system, protection against over-charge and under-charge of the supercapacitor and gives flexibility to the sizing of the system components. The proposed control strategy has been evaluated using validated Simulink models against real-world operating data collected from a double-decker bus operating in London. It was demonstrated that the control strategy was capable of meeting the operating power demands of the bus and that a wide range of degrees of hybridisation are viable for achieving this. Comparison between the degree of hybridisation proposed in this study and those in operational fuel cell (FC) hybrid buses was carried out. It was found that the FC size requirement and FC variation can be significantly reduced through the use of the degree of hybridisation identified in this study.


Author(s):  
Janner Leonel Santos Mantuano ◽  
Mario Javier Carreño Vera ◽  
Ever Nevárez Cedeño

A photovoltaic system is a set of devices that take advantage of the energy produced by the sun and convert it into electrical energy. The impact produced by the possibility of using solar energy in a controlled manner for different uses and purposes has allowed the development of complete systems of transformation, storage and distribution of the energy produced with photovoltaic systems as appropriate. The production of electricity from solar radiation using solar cells and photovoltaic panels is an application that has yet fully disseminated in Third World countries, such as Ecuador. The generation of electric power will depend on the hours that the sun shines and affects the solar panel, the type and quantity of modules installed, orientation, inclination, solar radiation that reaches them, quality of the installation and the power that can be delivered to the user. Ecuador is in a privileged location in terms of solar radiation, because the equatorial line that divides the planet into two hemispheres passes through it, being almost perpendicular to the radiation it receives. In addition, this does not change during the year and there a constant angle of incidence, characteristics that give photovoltaic solar energy a great potential for use. In the investigation, an analysis of how the prices of photovoltaic systems affect the Province of Manabí, the methodology used has been the bibliographic review to know as much as possible about what replenishes the costs of photovoltaic systems.


Author(s):  
Y.M. Irwan ◽  
A.R. Amelia ◽  
M. Irwanto ◽  
W.Z. Leow ◽  
Z. Syafiqah ◽  
...  

An increasing efficiency of the solar system can be improved by using hybrid cooling mechanism. This paper presents the impact of hybrid cooling mechanism on PV panel under indoor testing with varying solar intensity. Thus, the fabrication of a solar simulator for indoor testing reacts as the space solar radiation is described. The performance of PV panel which attached to a hybrid cooling mechanism compared with PV panel without cooling mechanism under variation of average solar radiation. Experimental tests were carried out for various average solar radiations by varying the number of lamps and/or the lamp-to-area distance. Without altering the spectral distribution, the characteristic of current-voltage of PV panel was analysed under average solar radiation which varied from 202 W/m<sup>2</sup> to 1003 W/m<sup>2</sup>. As the result, the PV panel with hybrid cooling system explored to generate more power output with decreasing in PV panel temperature. About 15.79 % increment of power output generated by PV panel with cooling at maximum average solar radiation. Furthermore, the PV panel temperature also can be decreased about 10.28 % respectively. The combination of DC fan and water pump as cooling mechanism plays an important role in generating efficient power output from PV panel.


2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Matthew Lave ◽  
Joshua Stein ◽  
Ryan Smith

To address the lack of knowledge of local solar variability, we have developed and deployed a low-cost solar variability datalogger (SVD). While most currently used solar irradiance sensors are expensive pyranometers with high accuracy (relevant for annual energy estimates), low-cost sensors display similar precision (relevant for solar variability) as high-cost pyranometers, even if they are not as accurate. In this work, we present evaluation of various low-cost irradiance sensor types, describe the SVD, and present validation and comparison of the SVD collected data. The low cost and ease of use of the SVD will enable a greater understanding of local solar variability, which will reduce developer and utility uncertainty about the impact of solar photovoltaic (PV) installations and thus will encourage greater penetrations of solar energy.


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