Modeling Photovoltaic Power

A robust and reliable model describing the power produced by a photovoltaic system is needed in order to be able to detect module failures, inverter malfunction, shadowing effects and other factors that may result to energy losses. In addition, a reliable model enables an investor to perform accurate estimates of the system energy production, payback times etc. The model utilizes the global irradiance reaching the plane of the photovoltaic modules since in almost all Photovoltaic (PV) facilities the beam and the diffuse solar irradiances are not recorded. The airmass, the angle of incidence and the efficiency drop due to low values of solar irradiance are taken into account. Currently, the model is validated through the use of high quality data available from the National Renewable Energy Laboratory (USA). The data were acquired with IV tracers while the meteorological conditions were also recorded. Several modules of different technologies were deployed but here we present results from a single crystalline module. The performance of the model is acceptable at a level of 5% despite the assumptions made. The dependence of the residuals upon solar irradiance temperature, airmass and angle of incidence is also explored and future work is described.

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Potential of existing online 24-hour dietary recall tools for national dietary surveys

Public Health Nutrition ◽

10.1017/s1368980021003517 ◽

2021 ◽

pp. 1-62

Author(s):

Rozenn Gazan ◽

Florent Vieux ◽

Ségolène Mora ◽

Sabrina Havard ◽

Carine Dubuisson

Keyword(s):

Grey Literature ◽

Quality Data ◽

High Quality Data ◽

Require Time ◽

Dietary Recall ◽

Dietary Surveys ◽

Almost All ◽

The Cost ◽

Web Platform ◽

Country Specific

Abstract Objective: To describe existing online 24-hour dietary recall (24hDR) tools in terms of functionalities and ability to tackle challenges encountered during national dietary surveys, such as maximizing response rates and collecting high-quality data from a representative sample of the population, while minimizing the cost and response burden. Design: A search (from 2000 to 2019) was conducted in peer-reviewed and grey literature. For each tool, information on functionalities, validation and user usability studies, and potential adaptability for integration into a new context was collected. Setting: Not country-specific Participants: General population Results: Eighteen online 24hDR tools were identified. Most were developed in Europe, for children ≥10 years old and/or for adults. Eight followed the five multiple-pass steps, but used various methodologies and features. Almost all tools (except three) validated their nutrient intake estimates, but with high heterogeneity in methodologies. User usability was not always assessed, and rarely by applying real-time methods. For researchers, eight tools developed a web platform to manage the survey and five appeared to be easily adaptable to a new context. Conclusions: Among the eighteen online 24hDR tools identified, the best candidates to be used in national dietary surveys should be those that were validated for their intake estimates, had confirmed user and researcher usability, and seemed sufficiently flexible to be adapted to new contexts. Regardless of the tool, adaptation to another context will still require time and funding, and this is probably the most challenging step.

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Measuring solar spectral and angle-of-incidence effects on photovoltaic modules and solar irradiance sensors

Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997 ◽

10.1109/pvsc.1997.654283 ◽

2002 ◽

Cited By ~ 47

Author(s):

D.L. King ◽

J.A. Kratochvil ◽

W.E. Boyson

Keyword(s):

Solar Irradiance ◽

Angle Of Incidence ◽

Photovoltaic Modules

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Spatial structure of grassland patches in Poland: implications for nature conservation

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.3615 ◽

2019 ◽

Vol 88 (1) ◽

Cited By ~ 1

Author(s):

Tomasz Henryk Szymura ◽

Magdalena Szymura

Keyword(s):

Protected Areas ◽

Quality Data ◽

High Quality Data ◽

Ecological Corridors ◽

Average Value ◽

Irregular Shapes ◽

Wide Range ◽

Seminatural Grasslands ◽

Almost All ◽

Grassland Biodiversity

Grasslands provide wide range of ecosystem services, however, their area and quality are still diminishing in Europe. Nowadays, they often create isolated patches inside “sea” of other habitats. We have examined basic structural landscape metrics of grasslands in Poland using CORINE land use database. Characteristics for both all individual patches as well as average values for 10 × 10-km grid covering Poland were examined. We also assessed the percentage of grasslands within protected areas and ecological corridors. We found that in Poland rather small patches (0.3–1 km2) dominate, usually located 200–500 m away from each other. The grasslands had clumped distribution, thus in Poland exist large areas where grasslands patches are separated kilometers from each other. Almost all indices calculated for 10 × 10-km2 were correlated, i.e., in regions with high percentage of grasslands, the patches were large, more numerous, placed close to each other, and had more irregular shapes. Our results revealed that the percentage of grasslands within protected areas and ecological corridors did not differ from the average value for Poland. On the other hand, forests were significantly over-represented in protected areas and ecological corridors. These findings suggest that there is no planned scheme for grassland protection at the landscape scale in Poland. Development the scheme is urgent and needs high-quality data regarding distribution of seminatural grasslands patches. In practice, nature conservationists and managers should consider spatial processes in their plans in order to maintain grassland biodiversity.

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Building a Sample Frame of SMEs Using Patent, Search Engine, and Website Data

Journal of Official Statistics ◽

10.2478/jos-2021-0001 ◽

2021 ◽

Vol 37 (1) ◽

pp. 1-30

Author(s):

Sanjay K. Arora ◽

Sarah Kelley ◽

Sarvothaman Madhavan

Keyword(s):

Low Cost ◽

Data Sources ◽

Quality Data ◽

Reasonable Accuracy ◽

High Quality ◽

High Quality Data ◽

Patent Search ◽

Data Matching ◽

Data Collections ◽

Future Work

Abstract This research outlines the process of building a sample frame of US SMEs. The method starts with a list of patenting organizations and defines the boundaries of the population and subsequent frame using free to low-cost data sources, including search engines and websites. Generating high-quality data is of key importance throughout the process of building the frame and subsequent data collection; at the same time, there is too much data to curate by hand. Consequently, we turn to machine learning and other computational methods to apply a number of data matching, filtering, and cleaning routines. The results show that it is possible to generate a sample frame of innovative SMEs with reasonable accuracy for use in subsequent research: Our method provides data for 79% of the frame. We discuss implications for future work for researchers and NSIs alike and contend that the challenges associated with big data collections require not only new skillsets but also a new mode of collaboration.

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Solar Irradiance Forecast Based on Cloud Movement Prediction

Energies ◽

10.3390/en14133775 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3775

Author(s):

Aleksander Radovan ◽

Viktor Šunde ◽

Danijel Kučak ◽

Željko Ban

Keyword(s):

Energy Storage ◽

Solar Energy ◽

Solar Irradiance ◽

Energy Production ◽

Storage System ◽

Prediction Method ◽

System Optimization ◽

Photovoltaic System ◽

Solar Irradiation ◽

Cloud Detection

Solar energy production based on a photovoltaic system is closely related to solar irradiance. Therefore, the planning of production is based on the prediction of solar irradiance. The optimal use of different energy storage systems requires an accurate prediction of solar irradiation with at least an hourly time horizon. In this work, a solar irradiance prediction method is developed based on the prediction of solar shading by clouds. The method is based on determining the current cloud position and estimating the velocity from a sequence of multiple images taken with a 180-degree wide-angle camera with a resolution of 5 s. The cloud positions for the next hour interval are calculated from the estimated current cloud position and velocity. Based on the cloud position, the percentage of solar overshadowing by clouds is determined, i.e., the solar overshadowing curve for the next hour interval is calculated. The solar irradiance is determined by normalizing the percentage of the solar unshadowing curve to the mean value of the irradiance predicted by the hydrometeorological institute for that hourly interval. Image processing for cloud detection and localization is performed using a computer vision library and the Java programming language. The algorithm developed in this work leads to improved accuracy and resolution of irradiance prediction for the next hour interval. The predicted irradiance curve can be used as a predicted reference for solar energy production in energy storage system optimization.

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Impact of Partial Shading on the P-V Characteristics and the Maximum Power of a Photovoltaic String

Energies ◽

10.3390/en11071860 ◽

2018 ◽

Vol 11 (7) ◽

pp. 1860 ◽

Cited By ~ 36

Author(s):

J. Teo ◽

Rodney Tan ◽

V. Mok ◽

Vigna Ramachandaramurthy ◽

ChiaKwang Tan

Keyword(s):

Critical Point ◽

Solar Irradiance ◽

Characteristic Curve ◽

Electrical Power ◽

Maximum Power ◽

Photovoltaic System ◽

Partial Shading ◽

Photovoltaic Modules ◽

The Impact

A photovoltaic system is highly susceptible to partial shading. Based on the functionality of a photovoltaic system that relies on solar irradiance to generate electrical power, it is tacitly assumed that the maximum power of a partially shaded photovoltaic system always decreases as the shading heaviness increases. However, the literature has reported that this might not be the case. The maximum power of a partially shaded photovoltaic system under a fixed configuration and partial shading pattern can be highly insusceptible to shading heaviness when a certain critical point is met. This paper presents an investigation of the impact of partial shading and the critical point that reduce the susceptibility of shading heaviness. Photovoltaic string formed by series-connected photovoltaic modules is used in this research. The investigation of the P-V characteristic curve under different numbers of shaded modules and shading heaviness suggests that the photovoltaic string becomes insusceptible to shading heaviness when the shaded modules irradiance reaches a certain critical point. The critical point can vary based on the number of the shaded modules. The formulated equation in this research contributes to determining the critical point for different photovoltaic string sizes and numbers of shaded modules in the photovoltaic string.

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A Survey on Exchanging Data Using MQTT Protocol in Arduino

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.37007 ◽

2021 ◽

Vol 9 (VII) ◽

pp. 3081-3082

Author(s):

Arefa Shafique Shaikh

Keyword(s):

Communication Protocol ◽

Quality Data ◽

The Internet ◽

Bandwidth Efficiency ◽

Light Weight ◽

High Quality ◽

High Quality Data ◽

Message Queue ◽

Almost All ◽

The Internet Of Things

In the coming years, sensors will likely grow in every aspect of our lives. Several activities explain how the Internet of Things (IoT) will have an impact on almost all aspect of our lives and why security is at the top of the list of IoT challenges. Device to Device communications (D2D) in IoT are forecast and another major concern within the use of IoT is to make sure device security, D2D connectivity and high quality data. Therefore, a proper communication protocol is required to fix this issues. To address this, we purpose the use of Message Queue Telemetry Transport(MQTT)protocol to transfer data between devices, as it is more secured. MQTT (Message Queuing Telemetry Transport) is a publish/subscribe messaging protocol which works on top of the TCP/IP protocol. The key feature of MQTT is its light weight, adds flexible authentication and bandwidth efficiency. The result of this study is transferring high quality data securely using MQTT protocol.

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Toward understanding the impact of artificial intelligence on labor

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1900949116 ◽

2019 ◽

Vol 116 (14) ◽

pp. 6531-6539 ◽

Cited By ~ 33

Author(s):

Morgan R. Frank ◽

David Autor ◽

James E. Bessen ◽

Erik Brynjolfsson ◽

Manuel Cebrian ◽

...

Keyword(s):

Artificial Intelligence ◽

Technological Change ◽

Quality Data ◽

Urban Migration ◽

High Quality Data ◽

Equilibrium Behavior ◽

Fundamental Uncertainty ◽

Almost All ◽

Work Done ◽

The Impact

Rapid advances in artificial intelligence (AI) and automation technologies have the potential to significantly disrupt labor markets. While AI and automation can augment the productivity of some workers, they can replace the work done by others and will likely transform almost all occupations at least to some degree. Rising automation is happening in a period of growing economic inequality, raising fears of mass technological unemployment and a renewed call for policy efforts to address the consequences of technological change. In this paper we discuss the barriers that inhibit scientists from measuring the effects of AI and automation on the future of work. These barriers include the lack of high-quality data about the nature of work (e.g., the dynamic requirements of occupations), lack of empirically informed models of key microlevel processes (e.g., skill substitution and human–machine complementarity), and insufficient understanding of how cognitive technologies interact with broader economic dynamics and institutional mechanisms (e.g., urban migration and international trade policy). Overcoming these barriers requires improvements in the longitudinal and spatial resolution of data, as well as refinements to data on workplace skills. These improvements will enable multidisciplinary research to quantitatively monitor and predict the complex evolution of work in tandem with technological progress. Finally, given the fundamental uncertainty in predicting technological change, we recommend developing a decision framework that focuses on resilience to unexpected scenarios in addition to general equilibrium behavior.

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Experimental Application of Methods to Compute Solar Irradiance and Cell Temperature of Photovoltaic Modules

Sensors ◽

10.3390/s20092490 ◽

2020 ◽

Vol 20 (9) ◽

pp. 2490

Author(s):

Caio Felippe Abe ◽

João Batista Dias ◽

Gilles Notton ◽

Ghjuvan Antone Faggianelli

Keyword(s):

Solar Irradiance ◽

Photovoltaic System ◽

Photovoltaic Module ◽

Electrical Measurements ◽

Cell Temperature ◽

Photovoltaic Modules ◽

Order Of Magnitude ◽

Simple Implementation ◽

Temperature Levels ◽

Mean Square Errors

Solar irradiance and cell temperature are the most significant aspects when assessing the production of a photovoltaic system. To avoid the need of specific sensors for quantifying such parameters, recent literature presents methods to estimate them through electrical measurements, using the photovoltaic module itself as a sensor. This work presents an application of such methods to data recorded using a research platform at University of Corsica, in France. The methods and the platform are briefly presented and the results are shown and discussed in terms of normalized mean absolute errors (nMAE) and root mean square errors (nRMSE) for various irradiance and cell temperature levels. The nMAE (and nRMSE) for solar irradiance are respectively between 3.5% and 3.9% (4.2% and 4.7%). Such errors on computed irradiance are in the same order of magnitude as those found in the literature, with a simple implementation. For cell temperatures estimation, the nMAE and nRMSE were found to be in the range 3.4%–8.2% and 4.3%–10.7%. These results show that using such methods could provide an estimation for the values of irradiance and cell temperature, even if the modules are not new and are not regularly cleaned, but of course not partially shaded.

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What Can Digitization Do For Formulated Product Innovation and Development

10.26434/chemrxiv.11763864.v1 ◽

2020 ◽

Author(s):

James McDonagh ◽

William Swope ◽

Richard L. Anderson ◽

Michael Johnston ◽

David J. Bray

Keyword(s):

High Performance ◽

Quality Data ◽

High Quality Data ◽

Base Level ◽

Hybrid Approaches ◽

Digital Ecosystem ◽

Recent Developments ◽

Chemical Simulation ◽

High Level ◽

Physical And Chemical

Digitization oﬀers signiﬁcant opportunities for the formulated product industry to transform the way it works and develop new methods of business. R&D is one area of operation that is challenging to take advantage of these technologies due to its high level of domain specialisation and creativity but the beneﬁts could be signiﬁcant. Recent developments of base level technologies such as artiﬁcial intelligence (AI)/machine learning (ML), robotics and high performance computing (HPC), to name a few, present disruptive and transformative technologies which could oﬀer new insights, discovery methods and enhanced chemical control when combined in a digital ecosystem of connectivity, distributive services and decentralisation. At the fundamental level, research in these technologies has shown that new physical and chemical insights can be gained, which in turn can augment experimental R&D approaches through physics-based chemical simulation, data driven models and hybrid approaches. In all of these cases, high quality data is required to build and validate models in addition to the skills and expertise to exploit such methods. In this article we give an overview of some of the digital technology demonstrators we have developed for formulated product R&D. We discuss the challenges in building and deploying these demonstrators.

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