scholarly journals Temperature Analysis of the Stand-Alone and Building Integrated Photovoltaic Systems Based on Simulation and Measurement Data

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4274
Author(s):  
Adam Idzkowski ◽  
Karolina Karasowska ◽  
Wojciech Walendziuk
Keyword(s):  
Power Plants ◽  
Photovoltaic Effect ◽  
Measurement Data ◽  
Operating Conditions ◽  
Photovoltaic System ◽  
Solar Array ◽  
Energy Yield ◽  
Photovoltaic Systems ◽  
Actual Measurement ◽  
The Impact

Sunlight is converted into electrical energy due to the photovoltaic effect in photovoltaic cells. Energy yield of photovoltaic systems depends on the solar array location, orientation, tilt, tracking and local weather conditions. In order to determine the amount of energy produced in a photovoltaic system, it is important to analyze the operation of the photovoltaic (PV) arrays in real operating conditions and take into account the impact of external factors such as irradiance, ambient temperature or the speed of blowing wind, which is the natural coolant of PV panels. The analysis was carried out based on mathematical models and actual measurement data, regarding the dependence of the average temperature of PV arrays on variable and difficult to predict ambient conditions. The analysis used standard (nominal operating cell temperature (NOCT)), King, Skoplaki, Faiman and Mattei thermal models and the standard model for flat-plate photovoltaic arrays. Photovoltaic installations PV1, PV2a and PV2b, being part of the hybrid power plant of the Bialystok University of Technology, Poland, were the objects of the research. In the case of a free-standing solar system, the Skoplaki model proved to be the best method for determining the average temperatures of the PV arrays. For building-integrated PV systems, a corrected value of the mounting coefficient in the Skoplaki model was proposed, and the original results were compared. The comparison of the accuracy measures of the average operating temperatures for three micro-power plants, differently mounted and located, is presented.

scholarly journals Analysis of Three Small-Scale Photovoltaic Systems Based on Simulation and Measurement Data

Proceedings ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 19
Author(s):  
Adam Idzkowski ◽  
Karolina Karasowska ◽  
Wojciech Walendziuk
Keyword(s):  
Mean Squared Error ◽  
Photovoltaic Effect ◽  
Measurement Data ◽  
Simulation Software ◽  
Solar Array ◽  
Small Scale ◽  
Energy Yield ◽  
Photovoltaic Systems ◽  
Average Temperature ◽  
Photovoltaic Arrays

Sunlight is converted into electrical energy due to the photovoltaic effect in photovoltaic arrays. The energy yield of photovoltaic systems depends on the solar array location, orientation, tilt, tracking and local weather conditions. Currently, simulation software is most often used to analyze the operation of photovoltaic (PV) systems and to estimate the energy yield. In this article, the differences in energy yield calculations given by the simulation software and the measured data are determined. The analysis was carried out based on mathematical models and real measurement data, regarding the dependence of the average temperature of PV arrays on variable and difficult to predict ambient conditions. For the purpose of this analysis, thermal models for flat-plate photovoltaic arrays were used. The photovoltaic installations PV1, PV2a and PV2b, belonging to the hybrid power plant of the Bialystok University of Technology in Poland, were indicated as the data source. There is no universal mathematical model to determine the average temperature of the PV modules for every type of the installation with a small normalized root-mean-squared error. The Skoplaki model proved to be the best method in the case of a free-standing solar system. On the other hand, the data values obtained from building integrated installations were better modeled by a method which used parameters under NOCT (Normal Operating Cell Temperature) conditions.

scholarly journals Floating photovoltaic system for Indian artificial reservoirs—an effective approach to reduce evaporation and carbon emission

2021 ◽  
Author(s):  
N. Ravichandran ◽  
N. Ravichandran ◽  
B. Panneerselvam
Keyword(s):  
Power Plants ◽  
Carbon Emission ◽  
Photovoltaic System ◽  
Electrical Performance ◽  
Innovative Technology ◽  
Energy Yield ◽  
Photovoltaic Systems ◽  
Hydroelectric Power ◽  
Emission Analysis ◽  
Hydroelectric Power Plants

AbstractFloating photovoltaic system for reservoirs is a recent innovative technology that is highly advantageous in reducing evaporation while generating solar power. In addition, the integration of floating photovoltaic systems with the existing hydroelectric power plants will increase renewable power production. The present study aims to assess the electrical performance of floating photovoltaic systems in major reservoirs with existing hydroelectric power plants in India. The reservoirs with large water surface area were selected for the study, and a model floating photovoltaic system with a 5-MW capacity was designed for the selected reservoirs. The numerical analysis showed that installing floating photovoltaic systems will result in an annual energy yield of 160 GWh. Further, the systems also save 1.40 million cubic meters of water per day and also help in generating additional energy of 514.80 MWh/day from the saved water through its integration with hydroelectric power plants. A single-axis tracking mechanism to the floating photovoltaic systems will increase the annual energy generation by 11%. The detailed cost analysis and carbon emission analysis were also carried out. The results indicate that the tracking mechanisms increase the total installation cost of the systems. The annual carbon emission reduction from the floating photovoltaic systems accounts for about 3.30 million tons of CO2. The obtained results highlight the suitability of this innovative technology for installation in Indian reservoirs and its effectiveness in reducing evaporation and carbon emission. Graphic abstract

scholarly journals Influence of Lawns on the Summer Thermal Environment and Microclimate of Heritage Sites: A Case Study of Fuling Mausoleum, China

2020 ◽  
Author(s):  
Xiaoyu Wang ◽  
Peng Liu ◽  
Gongwen Xu
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Thermal Environment ◽  
Measurement Data ◽  
Ground Temperature ◽  
Rapid Urbanization ◽  
Actual Measurement ◽  
Heritage Sites ◽  
Human Thermal Comfort ◽  
The Impact

Abstract The thermal environment and microclimate of heritage sites has been severely impacted by rapid urbanization. This study collected various meteorological measurement data as a reference for computational fluid dynamics (CFD) simulation settings. Then CFD was applied to simulate the impact of lawns on the thermal environment and microclimate of Fuling Mausoleum. We found that lawns and soil can cool the air through evaporation, and thus have a specific cooling effect on the bricked ground. After lawns were planted, the bricked ground temperature decreased by 1.56–17.54°C than that before lawns were planted at 14:00, a decrease of 2.68%–24.20%. Under normal circumstances, when the wind speed or relative humidity increased, the ground temperature dropped. Greenbelt vegetation can adjust the microclimate and human thermal comfort indicators. The consistency of the difference between the actual measurement and the CFD simulation results shows that CFD simulation can thus accurately reflect the internal temperature field distribution if the selection of simulation parameters is reasonable. Theoretical calculation and analysis, experimental measurement research, and modern computer simulation analysis methods applied together constitute a complete system for studying modern physical environmental problems and can provide reliable and economic results.

Root Cause of Thermal Sleeve Loosening in a Korean Standard Nuclear Power Plant

2006 ◽  
Author(s):  
Sang-Nyung Kim ◽  
Sang-Gyu Lim
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Measurement Data ◽  
Significant Loss ◽  
Design Modification ◽  
Root Cause ◽  
Explosive Expansion ◽  
The Impact

The safety injection (SI) nozzle of a 1000MWe-class Korean standard nuclear power plant (KSNP) is fitted with thermal sleeves (T/S) to alleviate thermal fatigue. Thermal sleeves in KSNP #3 & #4 in Yeonggwang (YG) & Ulchin (UC) are manufactured out of In-600 and fitted solidly without any problem, whereas KSNP #5 & #6 in the same nuclear power plants, also fitted with thermal sleeves made of In-690 for increased corrosion resistance, experienced a loosening of thermal sleeves in all reactors except KSNP YG #5-1A, resulting in significant loss of generation availability. An investigation into the cause of the loosening of the thermal sleeves only found out that the thermal sleeves were subject to severe vibration and rotation, failing to uncover the root cause and mechanism of the loosening. In an effort to identify the root cause of T/S loosening, three suspected causes were analyzed: (1) the impact force of flow on the T/S when the safety SI nozzle was in operation, (2) the differences between In-600 and In-690 in terms of physical and chemical properties (notably the thermal expansion coefficient), and (3) the positioning error after explosive expansion of the T/S as well as the asymmetric expansion of T/S. It was confirmed that none of the three suspected causes could be considered as the root cause. However, after reviewing design changes applied to the Palo Verde nuclear plant predating KSNP YG #3 & #4 to KSNP #5 & #6, it was realized that the second design modification (in terms of groove depth & material) had required an additional explosive energy by 150% in aggregate, but the amount of gunpowder and the explosive expansion method were the same as before, resulting in insufficient explosive force that led to poor thermal sleeve expansion. T/S measurement data and rubbing copies also support this conclusion. In addition, it is our judgment that the acceptance criteria applicable to T/S fitting was not strict enough, failing to single out thermal sleeves that were not expanded sufficiently. Furthermore, the T/S loosening was also attributable to lenient quality control before and after fitting the T/S that resulted in significant uncertainty. Lastly, in a flow-induced vibration test planned to account for the flow mechanism that had a direct impact upon the loosening of the thermal sleeves that were not fitted completely, it was discovered that the T/S loosening was attributable to RCS main flow. In addition, it was proven theoretically that the rotation of the T/S was induced by vibration.

scholarly journals Impact Study on Power Generation from Photovoltaic System due to Change in Local Irradiance and Temperature at Kathmandu Valley, Nepal

2017 ◽  
Vol 12 (1) ◽  
pp. 1-9
Author(s):  
Manish Shrestha ◽  
Nawraj Bhattarai
Keyword(s):  
Meteorological Data ◽  
Operating Conditions ◽  
Photovoltaic System ◽  
Photovoltaic Module ◽  
Kathmandu Valley ◽  
Solar Photovoltaic ◽  
Impact Study ◽  
Simulation And Experiment ◽  
Solar Photovoltaic System ◽  
The Impact

Solar Photovoltaic system has become popular among the renewable energy due to free availability and low maintenance costs. Economically, the decreasing cost from continuous development adds another motive for the use of photovoltaic system. There has been a continuous study regarding the estimation on output of the photovoltaic system, in normal operating conditions. The output is subject to variations due to various environmental factors. The aim of this study is to evaluate how Design of Experiments (DoE) Method is used to model the impact of meteorological data on the electric power generated by the photovoltaic system. In this paper, the simulation and experiment based analysis has been presented and the degree of impact of irradiance and temperature on the output power of the photovoltaic module has been illustrated.Journal of the Institute of Engineering, 2016, 12(1): 1-9

scholarly journals The Economic and Geographical Aspects of the Status of Small-Scale Photovoltaic Systems in Hungary—A Case Study

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3489 ◽  
Author(s):  
Gábor Pintér ◽  
Henrik Zsiborács ◽  
Nóra Hegedűsné Baranyai ◽  
András Vincze ◽  
Zoltán Birkner
Keyword(s):  
Power Plants ◽  
Photovoltaic System ◽  
Small Scale ◽  
Photovoltaic Systems ◽  
Comprehensive Investigation ◽  
Photovoltaic Power ◽  
The Status ◽  
Average Size ◽  
Geographical Locations

The use of solar energy is an obvious choice; the energy of the sun is not only indispensable for most processes in nature but it is also a clean, abundant, sustainable, and—most importantly—universally available resource. Although the further spread of photovoltaic systems, which make use of this source of energy, is expected in the future all around the world, no comprehensive investigation has been conducted into the current situation of the small-scale photovoltaic power plants in Hungary, where this type of photovoltaic system is the most popular. By means of a case study, whose novelty lies in its focus on small-scale power plants and their complex examination, including economic and geographic indicators, this paper analyzes their status in Hungary. The study endeavors to establish the reasons for the popularity of this type of power plant and to identify some typical geographical locations with well-illustrated photovoltaic density. Residential, as well as business prosumers, were examined with the aim of learning more about the density of the small-scale photovoltaic systems and their geographical locations. Another goal was to calculate the average size of small-scale photovoltaic power plants and to gain more understanding of their economic aspects. The outcomes of this research include maps displaying the density of the small-scale photovoltaic power plants in Hungary and the results of the economic calculations for such investments.

Geothermal Power Cycle Analysis for Commercial Applicability Using Sequestered Supercritical CO2 as a Heat Transfer or Working Fluid

2011 ◽  
Author(s):  
Brian Janke ◽  
Thomas Kuehn
Keyword(s):  
Heat Transfer ◽  
Binary System ◽  
Power Plants ◽  
Power Production ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Direct System ◽  
Geothermal Power ◽  
The Impact

Thermodynamic analysis has been conducted for geothermal power cycles using a portion of deep ground sequestered CO2 as the working fluid. This allows energy production from much shallower depths and in geologic areas with much lower temperature gradients than those of current geothermal systems. Two different system designs were analyzed for power production with varying reservoir parameters, including reservoir depth, temperature, and CO2 mass flow rate. The first design is a direct single-loop system with the CO2 run directly through the turbine. This system was found to provide higher system efficiency and power production, however design complications such as the need for high pressure turbines, two-phase flow through the turbine and the potential for water-CO2 brine mixtures, could require the use of numerous custom components, driving up the cost. The second design is a binary system using CO2 as the heat transfer fluid to supply thermal energy to an Organic Rankine Cycle (ORC). While this system was found to have slightly less power production and efficiency than the direct system, it significantly reduces the impact of design complications associated with the direct system. This in turn reduces the necessity for certain custom components, thereby reducing system cost. While performance of these two systems is largely dependent on location and operating conditions, the binary system is likely applicable to a larger number of sites and will be more cost effective when used in combination with current off-the-shelf ORC power plants.

scholarly journals Photovoltaic system implementation in baltra and puerto ayora islands

2018 ◽  
Vol 2 (3) ◽  
pp. 20-27
Author(s):  
Epeni-Tombo Genial Belvinel ◽  
Guillermo Antonio Loor ◽  
Julio Cesar Hernandez Chilan ◽  
Maria Rodriguez Gamez
Keyword(s):  
Environmental Impact ◽  
Total Energy ◽  
Electric Current ◽  
Photovoltaic System ◽  
Photovoltaic Systems ◽  
System Implementation ◽  
Galapagos Archipelago ◽  
The Impact ◽  
Made In ◽  
Modeling Study

In the research, an analysis of the impact of the photovoltaic systems installed in two islands of the Galápagos archipelago is made. In this sense, a series of calculations has been used to find the significant values that have allowed us to choose the specific devices for this project. A modeling study was analyzed to quantify the total energy of the system, the number of possible modules to be installed, the amount of energy to be stored according to the type of batteries and the ampere-hour (Ah) that the regulation set must support of the electric current. The socio-economic and environmental impact of the system on Baltra Island was assessed with an example and estimations to make it explicit, the results of the surveys used are shown through which the most significant results were exposed, exposing that the photovoltaic systems in stage of implantation do not affect the environment, flora and fauna, its greatest impact is in the use of land.

scholarly journals Optimal Power Flow Calculation Considering Large-Scale Photovoltaic Generation Correlation

2020 ◽  
Vol 8 ◽  
Author(s):  
He Li ◽  
Huijun Li ◽  
Weihua Lu ◽  
Zhenhao Wang ◽  
Jing Bian
Keyword(s):  
Power Flow ◽  
Power Plants ◽  
Optimal Power Flow ◽  
Large Scale ◽  
Short Term Memory ◽  
Photovoltaic System ◽  
Power Flow Calculation ◽  
Flow Calculation ◽  
Optimal Power ◽  
The Impact

In order to analyze the impact of large-scale photovoltaic system on the power system, a photovoltaic output prediction method considering the correlation is proposed and the optimal power flow is calculated. Firstly, establish a photovoltaic output model to obtain the attenuation coefficient and fluctuation amount, and analyze the correlation among the multiple photovoltaic power plants through the k-means method. Secondly, the long short-term memory (LSTM) neural network is used as the photovoltaic output prediction model, and the clustered photovoltaic output data is brought into the LSTM model to generate large-scale photovoltaic prediction results with the consideration of the spatial correlation. And an optimal power flow model that takes grid loss and voltage offset as targets is established. Finally, MATLAB is used to verify that the proposed large-scale photovoltaic forecasting method has higher accuracy. The multi-objective optimal power flow calculation is performed based on the NSGA-II algorithm and the modified IEEE systems, and the optimal power flow with photovoltaic output at different times is compared and analyzed.

Prediction and Mitigation Strategies for Compressor Instabilities due to Large Pressurized Volumes in Micro Gas Turbine Systems

2021 ◽  
Author(s):  
Thomas Krummrein ◽  
Martin Henke ◽  
Timo Lingstädt ◽  
Martina Hohloch ◽  
Peter Kutne
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Flow Instability ◽  
Measurement Data ◽  
Mitigation Strategies ◽  
Mathematical Explanation ◽  
Shaft Speed ◽  
Micro Gas Turbine ◽  
The Impact

Abstract Micro gas turbines are a versatile platform for advanced cycle concepts. In these novel cycles, basic micro gas turbine components — compressor, turbine, combustor and recuperator — are coupled with various other technologies to achieve higher efficiency and flexibility. Examples are hybrid power plants integrating pressurized fuel cells, solar receivers or thermal storages. Characteristically, such complex cycles contain vast pressurized gas volumes between compressor and turbine, many times larger than those contained in conventional micro gas turbines. In fast deceleration maneuvers the rotational speed of the compressor drops rapidly. However, the pressure decrease is delayed due to the large amount of gas contained in the volumes. Ultimately, this can lead to compressor flow instability or surge. To predict and mitigate such instabilities, not only the compressor surge limit must be known, but also the dynamic dependencies between shaft speed deceleration, pressure and flow changes within the system. Since appropriate experiments may damage the system, investigations with numerical simulations are crucial. The investigation begins with a mathematical explanation of the relevant mechanisms, based on a simplified analytical model. Subsequently, the DLR in-house simulation program TMTSyS (Transient Modular Turbo-System Simulator) is used to investigate the impact of transient maneuvers on a micro gas turbine test rig containing a large pressurized gas volume in detail. After the relevant aspects of the simulation model are validated against measurement data, it is shown that the occurrence of compressor instabilities induced by fast deceleration can be predicted with the simulator. It is also shown that the simulation tool enables these predictions using only measurement data of non-critical maneuvers. Hence, mitigation strategies are derived that allow to estimate save shaft speed deceleration rate limits based on non-critical performance measurements.

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