scholarly journals Linearised model for PV panel power output variation with changes in ambient conditions

Sadhana ◽  
2017 ◽  
Vol 42 (12) ◽  
pp. 2183-2187 ◽  
Author(s):  
PALLAVI BHARADWAJ ◽  
VINOD JOHN
Keyword(s):  
Power Output ◽  
Ambient Conditions ◽  
Pv Panel

Inlet Air Cooling Applied to Combined Cycle Power Plants: Influence of Site Climate and Thermal Storage Systems

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Power Output ◽  
Parametric Analysis ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Cooling Systems

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.

Experimental Investigation of a Flat Plate Photovoltaic/Thermal Collector

2018 ◽  
Author(s):  
Mohamad Modrek ◽  
Ali Al-Alili
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Electrical Power ◽  
Solar Thermal ◽  
Pv Panel ◽  
Solar Thermal Collectors ◽  
Electrical Power Output ◽  
Electrical Output

Photovoltaic thermal collectors (PVT) combines technologies of photovoltaic panels and solar thermal collectors into a hybrid system by attaching an absorber to the back surface of a PV panel. PVT collectors have gained a lot of attention recently due to the high energy output per unit area compared to a standalone system of PV panels and solar thermal collectors. In this study, performance of a liquid cooled flat PVT collector under the climatic conditions of Abu Dhabi, United Arab Emirates was experimentally investigated. The electrical performances of the PVT collector was compared to that of a standalone PV panel. Moreover, effect of sand accumulation on performance of PVT collectors was examined. Additionally, effect of mass flow rate on thermal and electrical output of PVT collector was studied. Electrical power output is slightly affected by changes in mass flow rate. However, thermal energy increased by 22% with increasing flow rate. Electrical power output of a PV panel was found to be 38% lower compared to electrical output of PVT collectors. Dust accumulation on PVT surface reduced electrical power output up to 7% compared with a reference PVT collector.

scholarly journals Core temperature up to 41.5ºC during the UCI Road Cycling World Championships in the heat

2018 ◽  
Vol 53 (7) ◽  
pp. 426-429 ◽  
Author(s):  
Sebastien Racinais ◽  
Sebastien Moussay ◽  
David Nichols ◽  
Gavin Travers ◽  
Taoufik Belfekih ◽  
...  
Keyword(s):  
Heart Rate ◽  
Core Temperature ◽  
Power Output ◽  
Temperature Response ◽  
Time Trial ◽  
Ambient Conditions ◽  
Wet Bulb Globe Temperature ◽  
Road Cycling ◽  
Road Race ◽  
Globe Temperature

ObjectiveTo characterise the core temperature response and power output profile of elite male and female cyclists during the 2016 UCI Road World Championships. This may contribute to formulating environmental heat stress policies.MethodsCore temperature was recorded via an ingestible capsule in 10, 15 and 15 cyclists during the team time trial (TTT), individual time trial (ITT) and road race (RR), respectively. Power output and heart rate were extracted from individual cycling computers. Ambient conditions in direct sunlight were hot (37°C±3°C) but dry (25%±16% relative humidity), corresponding to a wet-bulb globe temperature of 27°C±2°C.ResultsCore temperature increased during all races (p<0.001), reaching higher peak values in TTT (39.8°C±0.9°C) and ITT (39.8°C±0.4°C), relative to RR (39.2°C±0.4°C, p<0.001). The highest temperature recorded was 41.5°C (TTT). Power output was significantly higher during TTT (4.7±0.3 W/kg) and ITT (4.9±0.5 W/kg) than RR (2.7±0.4 W/kg, p<0.001). Heart rate increased during the TTs (p<0.001) while power output decreased (p<0.001).Conclusion85% of the cyclists participating in the study (ie, 34 of 40) reached a core temperature of at least 39°C with 25% (ie, 10 of 40) exceeding 40°C. Higher core temperatures were reached during the time trials than the RR.

scholarly journals Comparative study of the power output of a mobile PV panel and a fixed PV panel 

2021 ◽  
Vol 2 (1a) ◽  
pp. C20A02-1-C20A02-6
Author(s):  
Diatta Sène ◽  
◽  
Adama Sarr ◽  
Mouhamadou Falilou Ndiaye
Keyword(s):  
Comparative Study ◽  
Nous Avons ◽  
Power Output ◽  
Pv Panel ◽  
Énergies Renouvelables

Avec le coût élevé de l'électricité, les centrales électriques ne sont plus rentables et les énergies renouvelables deviennent un domaine d'étude privilégié. Cela justifie qu'au Sénégal, on constate de plus en plus la création de centrales photovoltaïques et de petites installations domestiques afin de satisfaire les besoins en électricité. Cependant, nous constatons une limitation des terrains pour répondre à nos besoins pour l'installation de ces centrales solaires PV. La question est de voir avec le peu d'espace dont nous disposons comment optimiser au maximum la quantité d'énergie pour répondre à la demande ? Comme l'inclinaison des panneaux photovoltaïques est souvent fixe et que cela ne donne pas toujours une énergie optimale, nous avons pensé aux suiveurs solaires. L'objectif de ce travail est de comparer la puissance de sortie des deux panneaux PV, avec les mêmes caractéristiques et dans les mêmes conditions environnementales. Pour ce faire, nous procédons en calculant la puissance maximale disponible à la sortie d'un panneau photovoltaïque. Cela consiste à rechercher les modèles mathématiques qui permettent de calculer cette puissance. Pour choisir le modèle le plus proche de la puissance caractéristique donnée par le fabricant du panneau PV dans les conditions de test, nous avons écrit un programme sous l'environnement Matlab, les résultats de ce script distinguent ce modèle. Les caractéristiques du panneau PV choisi sont appliquées dans chaque cas d'installation photovoltaïque. Ces résultats ont montré que la production du panneau PV mobile est plus importante que celle du panneau PV fixe. Nous avons constaté que la puissance électrique du panneau PV mobile produit plus de 10 à 38% supérieure à celle du panneau PV fixe selon le jour du mois considéré.

Power Enhancement of Gas Turbine Plant by Intake Air Fog Cooling

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
J. P. Yadav ◽  
Bharat Raj Singh ◽  
Onkar Singh
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Gas Turbines ◽  
Ambient Air ◽  
Summer Season ◽  
Ambient Conditions ◽  
Power Enhancement

Although gas turbines are known as constant volume machines, but its performance considerably depends upon the ambient air temperature and mass flow rate. During summer season the density of the air decreases which affects the mass flow rate and ultimately the power output of a gas turbine is reduced. In order to overcome this situation several techniques are already in the practice and one of the most effective and economical is adopting the inlet fog cooling, and this technique basically enhances the power output of the machine. The cooling of ambient air by fog cooling up to wet bulb temperature increases the mass flow rate on account of increase in air density, as a result it ultimately increases the power output of a gas turbine. Fogging is applied with consideration of relative humidity of ambient air not only during summer season but also during dry days of summer season in order to increase the power output of gas turbine. This paper describes the effect on percentage enhancement of power out adopting various fuel options with low and high humidity ambient conditions. The result indicates the potential increase in the power output up to 14%. It is also observed that the total cost of power production increases due to increase in fuel consumption on account of enhanced power output. Thus the best suitable selling cost of power should be selected to compensate the increased investment on fuel cost.

scholarly journals Microcontroller based maximum power point single axis Tracking System

2013 ◽  
Vol 47 (4) ◽  
pp. 427-432 ◽  
Author(s):  
Hafiz Ullah
Keyword(s):  
Power Output ◽  
Radiation Intensity ◽  
Tracking System ◽  
Maximum Power ◽  
Solar Irradiation ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Pv Panel ◽  
Solar Radiation Intensity ◽  
Power Point

Positioning a photovoltaic (PV) panel in the plane of maximum irradiation can increase the power output up to 57%. An automatic microcontroller based system for maximum power point tracking (MPPT) was designed and analyzed. The system was based on positioning the PV panel perpendicular to the solar irradiation. Photosensors were used to measure the difference of solar radiation intensity among three planes. The tracking system used an 8051 microcontroller to control a stepper motor which rotated the panel towards the plane with highest radiation intensity. The MPPT system was found to be 25.9% more effective in capturing solar power than a fixed panel with the same rating. This system would be useful to increase the power output of currently operating solar panels with minor modifications in mounting. Bangladesh J. Sci. Ind. Res. 47(4), 427-432, 2012 DOI: http://dx.doi.org/10.3329/bjsir.v47i4.4689

Effects of Intake Air Cooling Performance Improvement on a Two-Shaft Laboratory-Scale Gas Turbine Unit

2007 ◽  
Author(s):  
Hussain Al-Madani ◽  
Teoman Ayhan ◽  
Omar Al-Abbasi
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Performance Test ◽  
Second Law ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Proposed Model ◽  
Compressor Inlet

The present study deals with the thermodynamically modelled two-shaft gas turbine system consisting of a cooling unit at the compressor inlet. The system is used to investigate the generated power, thermal efficiency and second law efficiency. The parametric study using this model shows effect of ambient conditions, compressor inlet temperature, and pressure ratios on power output, thermal efficiency and second law efficiency. Theoretical results using the proposed model show that when the compressor inlet temperature is decreased by some kind of cooling systems, the net power output and thermal efficiency increases up to 30% and 23%, respectively. Also, the second law efficiency of the proposed system increases in compression to the specified reference state. It shows that the proposed model is thermodynamically viable. A comparison of the performance test results of the model and the experimental results are in good agreement. The results provide valuable information regarding the gas turbine system and will be useful for designers.

scholarly journals Combined ANFIS–Wavelet Technique to Improve the Estimation Accuracy of the Power Output of Neighboring PV Systems during Cloud Events

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1613 ◽  
Author(s):  
Hasanain A. H. Al-Hilfi ◽  
Ahmed Abu-Siada ◽  
Farhad Shahnia
Keyword(s):  
Power Output ◽  
Fuzzy Inference ◽  
Estimation Accuracy ◽  
Ambient Conditions ◽  
Pv System ◽  
Inference System ◽  
Pv Systems ◽  
Neuro Fuzzy ◽  
Irradiance Data ◽  
Reduction Index

The short-term variability of photovoltaic (PV) system-generated power due to ambient conditions, such as passing clouds, represents a key challenge for network planners and operators. Such variability can be reduced using a geographical smoothing technique based on installing multiple PV systems over certain locations at distances of meters to kilometers. To accurately estimate the PV system’s generated power during cloud events, a variability reduction index (VRI), which is a function of several parameters, should be calculated precisely. In this paper, the Wavelet Transform Technique (WTT) along with Adaptive Neuro Fuzzy Inference System (ANFIS) are used to develop new models to estimate the PV system’s power output during cloud events. In this context, irradiance data collected from one PV system along with other parameters, including ambient conditions, were used to develop the proposed models. Ultimately, the models were validated through their application on a 0.7 km2 PV plant with 16 rooftop PV systems in Brisbane, Australia.

Performance of a Novel Semiclosed Gas-Turbine Refrigeration Combined Cycle

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Joseph J. Boza ◽  
William E. Lear ◽  
S. A. Sherif
Keyword(s):  
High Pressure ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Combined Cycle ◽  
Water Mixture ◽  
Absorption Refrigeration ◽  
Ambient Conditions ◽  
Large Engine

A thermodynamic performance analysis was performed on a novel cooling and power cycle that combines a semiclosed gas turbine called the high-pressure regenerative turbine engine (HPRTE) with an absorption refrigeration unit. Waste heat from the recirculated combustion gas of the HPRTE is used to power the absorption refrigeration cycle, which cools the high-pressure compressor inlet of the HPRTE to below ambient conditions and also produces excess refrigeration depending on ambient conditions. Two cases were considered: a small engine with a nominal power output of 100kW and a large engine with a nominal power output of 40MW. The cycle was modeled using traditional one-dimensional steady-state thermodynamics, with state-of-the-art polytropic efficiencies and pressure drops for the turbomachinery and heat exchangers, and curve fits for properties of the LiBr-water mixture and the combustion products. The small engine was shown to operate with a thermal efficiency approaching 43% while producing 50% as much 5°C refrigeration as its nominal power output (roughly 50tons) at 30°C ambient conditions. The large engine was shown to operate with a thermal efficiency approaching 62% while producing 25% as much 5°C refrigeration as its nominal power output (roughly 20,000tons) at 30°C ambient conditions. Thermal efficiency stayed relatively constant with respect to ambient temperature for both the large and small engines. It decreased by only 3–4% as the ambient temperature was increased from 10°Cto35°C in each case. The amount of external refrigeration produced by the engine sharply decreased in both engines at around 35°C, eventually reaching zero at roughly 45°C in each case for 5°C refrigeration. However, the evaporator temperature could be raised to 10°C (or higher) to produce external refrigeration in ambient temperatures as high as 50°C.

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