New Spatio-Temporal Wind Exergy Maps

2006 ◽  
Vol 128 (3) ◽  
pp. 194-202 ◽  
Author(s):  
Ahmet Duran Şahin ◽  
Ibrahim Dincer ◽  
Marc A. Rosen
Keyword(s):  
Wind Energy ◽  
Wind Speeds ◽  
Common Basis ◽  
Energy And Exergy ◽  
New Energy ◽  
Temperature And Pressure ◽  
Spatio Temporal ◽  
Low Wind Speeds ◽  
Generating System

In this paper, energy and exergy characteristics of wind energy are investigated. The effects of wind speed and air temperature and pressure at the inlet of a wind turbine on windchill temperature are examined. We also investigate energy and exergy efficiencies of the wind energy generating system and verify the models through a case study on a 100 kW wind generating system for 21 climatic stations in the province of Ontario, Canada. New energy and exergy efficiency maps of the wind energy generating system are introduced to provide a common basis for regional assessments and interpretations. These efficiency maps are plotted for 4 months of the year (January, April, July, October), which are taken to be representative months of the seasons. The results show that aerial differences between energy and exergy efficiencies are approximately 20%–24% at low wind speeds and approximately 10%–15% at high wind speeds.

Development of New Spatio-Temporal Wind Exergy Maps

2006 ◽  
Author(s):  
Ahmet Duran Sahin ◽  
Ibrahim Dincer ◽  
Marc A. Rosen
Keyword(s):  
Wind Energy ◽  
Wind Speeds ◽  
Common Basis ◽  
Energy And Exergy ◽  
New Energy ◽  
Temperature And Pressure ◽  
Spatio Temporal ◽  
Low Wind Speeds ◽  
Generating System

In this paper, energy and exergy characteristics of wind energy are investigated. The effects of wind speed and air temperature and pressure at the inlet of a wind turbine on wind chill temperature are examined. We also investigate energy and exergy efficiencies of the wind energy generating system and verify the models through a case study on a 100-kW wind generating system for 21 climatic stations in the province of Ontario, Canada. New energy and exergy efficiency maps of the wind energy generating system are introduced to provide a common basis for regional assessments and interpretations. These efficiency maps are plotted for two months of the year (January and July), which are taken to be representative months of the winter and summer seasons. The results show that aerial differences between energy and exergy efficiencies are approximately to 20-24% at low wind speeds and approximately to 10-15% at high wind speeds.

Effect of Slotted Angle on Savonius Wind Turbine Performance

2021 ◽  
Vol 104 ◽  
pp. 83-88
Author(s):  
Rahmat Wahyudi ◽  
Diniar Mungil Kurniawati ◽  
Alfian Djafar
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Electrical Energy ◽  
Speed Ratio ◽  
Angle Variation ◽  
Wind Speeds ◽  
Turbine Performance ◽  
Savonius Wind Turbine ◽  
Low Wind Speeds

The potential of wind energy is very abundant but its utilization is still low. The effort to utilize wind energy is to utilize wind energy into electrical energy using wind turbines. Savonius wind turbines have a very simple shape and construction, are inexpensive, and can be used at low wind speeds. This research aims to determine the effect of the slot angle on the slotted blades configuration on the performance produced by Savonius wind turbines. Slot angle variations used are 5o ,10o , and 15o with slotted blades 30% at wind speeds of 2,23 m/s to 4,7 m/s using wind tunnel. The result showed that a small slot angle variation of 5o produced better wind turbine performance compared to a standard blade at low wind speeds and a low tip speed ratio.

scholarly journals Analisa Aliran Angin Pada Sudu Turbin Angin Savonius Tipe-U Berbasis Software

2018 ◽  
Vol 4 (2) ◽  
pp. 93
Author(s):  
Delffika - Canra ◽  
Meri Rahmi ◽  
Emin Haris
Keyword(s):  
Renewable Energy ◽  
Aspect Ratio ◽  
Wind Energy ◽  
Wind Turbine ◽  
Electrical Energy ◽  
Simulation Method ◽  
Renewable Energy Resources ◽  
Wind Speeds ◽  
Low Wind Speeds ◽  
Turbine Construction

Generally, wind energy sources in Indonesia's coastal areas is one of the potential sources of renewable energy (renewable energy resources) which are abundant, environmentally friendly and renewable. Savonius wind turbines can produce relatively high torque even at low wind speeds. Because it is very well developed to produce electrical energy. To get a large electric power, a large turbine construction is also needed which also certainly requires a large cost. For this reason, it is necessary to develop the dimensions of this wind turbine construction which is known as aspect ratio (Ar). The Ar that has been researched is the blade section, and other values. While the arch depth or the length of the blade arc in U -type is still likely to be researched. Therefore, it is necessary to do research on the U-type blade arc to get greater power than before. In addition to the experimental method with a prototype of the U type Savonius wind turbine with a number of 2 blades, a software-based simulation method will be carried out to analyze the air flow on the wind turbine blade. Parameters varied only with the aspect ratio of the arc length and blade cross section width, other parameters follow the previous research. This analysis will be a comparative data with experimental methods. The expected simulation results obtain the best aspect ratio (Ar) blade in capturing wind energy.

scholarly journals Meteorological Drivers of Permian Basin Methane Anomalies Derived from TROPOMI

2021 ◽  
Vol 13 (5) ◽  
pp. 896
Author(s):  
Erik Crosman
Keyword(s):  
The United States ◽  
Spatiotemporal Variations ◽  
Permian Basin ◽  
Wind Speeds ◽  
The North ◽  
Low Wind Speed ◽  
Westerly Winds ◽  
Meteorological Observations ◽  
Low Wind Speeds

The launch of the TROPOspheric Monitoring Instrument (TROPOMI) on the Sentinel-5 Precursor (S-5P) satellite has revolutionized pollution observations from space. The purpose of this study was to link spatiotemporal variations in TROPOMI methane (CH4) columns to meteorological flow patterns over the Permian Basin, the largest oil and second-largest natural gas producing region in the United States. Over a two-year period (1 December 2018–1 December 2020), the largest average CH4 enhancements were observed near and to the north and west of the primary emission regions. Four case study periods—two with moderate westerly winds associated with passing weather disturbances (8–15 March 2019 and 1 April–10 May 2019) and two other periods dominated by high pressure and low wind speeds (16–23 March 2019 and 24 September–9 October 2020)—were analyzed to better understand meteorological drivers of the variability in CH4. Meteorological observations and analyses combined with TROPOMI observations suggest that weakened transport out of the Basin during low wind speed periods contributes to CH4 enhancements throughout the Basin, while valley and slope flows may explain the observed western expansion of the Permian Basin CH4 anomaly.

scholarly journals Evaluation of wind speed estimates in reanalyses for wind energy applications

2021 ◽  
Vol 18 ◽  
pp. 115-126
Author(s):  
Sebastian Brune ◽  
Jan D. Keller ◽  
Sabrina Wahl
Keyword(s):  
Wind Speed ◽  
Wind Energy ◽  
Surface Characteristics ◽  
Horizontal Resolution ◽  
Hilly Terrain ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Energy Applications ◽  
Spatio Temporal ◽  
Regional Reanalysis

Abstract. A correct spatio-temporal representation of retrospective wind speed estimates is of large interest for the wind energy sector. In this respect, reanalyses provide an invaluable source of information. However, the quality of the various reanalysis estimates for wind speed are difficult to assess. Therefore, this study compares wind measurements at hub heights from 14 locations in Central Europe with two global (ERA5, MERRA-2) and one regional reanalysis (COSMO-REA6). Employing metrics such as bias, RMSE and correlation, we evaluate the performance of the reanalyses with respect to (a) the local surface characteristics (offshore, flat onshore, hilly onshore), (b) various height levels (60 to 200 m) and (c) the diurnal cycle. As expected, we find that the reanalyses show the smallest errors to observations at offshore sites. Over land, MERRA-2 generally overestimates wind speeds, while COSMO-REA6 and ERA5 represent the average wind speed more realistically. At sites with flat terrain, ERA5 correlates better with observations than COSMO-REA6. In contrast, COSMO-REA6 performs slightly better over hilly terrain, which can be explained by the higher horizontal resolution. In terms of diurnal variation, ERA5 outperforms both other reanalyses. While the overestimation of MERRA-2 is consistent throughout the day, COSMO-REA6 significantly underestimates wind speed at night over flat and hilly terrain due to a misrepresentation of nightly low level jets and mountain and valley breezes. Regarding the representation of downtime of wind turbines due to low/high wind speeds, we find that MERRA-2 is consistently underperforming with respect to the other reanalyses. Here COSMO-REA6 performs better over the ocean, while ERA5 shows the best results over land.

scholarly journals Harvesting Variable-Speed Wind Energy with a Dynamic Multi-Stable Configuration

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1389
Author(s):  
Yuansheng Wang ◽  
Zhiyong Zhou ◽  
Qi Liu ◽  
Weiyang Qin ◽  
Pei Zhu
Keyword(s):  
Wind Speed ◽  
Wind Energy ◽  
Stable Configuration ◽  
Variable Speed ◽  
Coherence Resonance ◽  
Wind Speeds ◽  
Piezoelectric Beam ◽  
Speed Range ◽  
Low Wind Speeds ◽  
Large Output

To harvest the energy of variable-speed wind, we proposed a dynamic multi-stable configuration composed of a piezoelectric beam and a rectangular plate. At low wind speeds, the system exhibits bi-stability, whereas, at high wind speeds, the system exhibits a dynamic tri-stability, which is beneficial for harvesting variable-speed wind energy. The theoretical analysis was carried out. For validation, the prototype was fabricated, and a piezoelectric material was bonded to the beam. The corresponding experiment was conducted, with the wind speed increasing from 1.5 to 7.5 m/s. The experiment results prove that the proposed harvester could generate a large output over the speed range. The dynamic stability is helpful to maintain snap-through motion for variable-speed wind. In particular, the snap-through motion could reach coherence resonance in a range of wind speed. Thus, the system could keep large output in the environment of variable-speed wind.

scholarly journals Turbin angin poros vertikal tipe Savonius bertingkat dengan variasi posisi sudut

2016 ◽  
Vol 6 (2) ◽  
Author(s):  
I.B. Alit ◽  
Nurchayati Nurchayati ◽  
S.H. Pamuji
Keyword(s):  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbine ◽  
Electric Power ◽  
Rotor Blade ◽  
Rotation Speed ◽  
Simple Construction ◽  
Wind Speeds ◽  
Turbine Performance ◽  
Low Wind Speeds

Wind turbine is a technology that converts wind energy to electric power. A Savonius type rotor blade is a simple wind turbine that operates on the concept of drag. The turbine has a potential to be developed as it has a simple construction and it is suitable for low wind speeds. Savonius rotor can be designed with two or three blades in single level or multi-levels. This research was conducted to obtain two levels wind turbine performance characteristics with variations in wind speed and different positions of angle on each level. The variations of the angle position of the wind turbine were 0°, 30°, 45°, 60°, and 90° in each stage. The result shows that the performance of the wind turbine is inversely to the degree of the angle position. The maximum rotation speed of the rotor was about 150.6 rpm that was generated at the wind speed of 5 m/s and the angle position of 0°. 

Parametrically Excited Nonlinear Piezoelectric Wind Energy Harvester

2011 ◽  
Author(s):  
M. Amin Karami ◽  
Justin R. Farmer ◽  
Scott Bressers ◽  
Shashank Priya ◽  
Daniel J. Inman
Keyword(s):  
Wind Energy ◽  
Electric Power ◽  
Axial Force ◽  
Power Output ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Power Production ◽  
Experimental Investigations ◽  
Wind Speeds ◽  
Low Wind Speeds

A nonlinear piezoelectric wind energy harvester is proposed which operates at low wind speeds and is not sensitive to the speed of the gusts. The piezoelectric transduction mechanism is used instead of DC generators to eliminate the gearbox in the windmill and thus reduces the friction. The reduced friction facilitates operation of the windmill at low wind speeds. Permanent magnets have been placed in the blade part of the windmill. The magnets axially repel another set of magnets which are positioned at the tip of the piezoelectric beams. As a result, when the rotating magnets pass over the piezoelectric beams they excite the beams and affect the type of their vibrations. The nature of excitations in the proposed design is therefore both parametric excitations and ordinary excitations. The nonlinear magnetic axial force makes the vibrations of the beams nonlinear and can make the beams bi-stable. This phenomenon is utilized to enhance the power output and to improve the robustness of the power production. Two designs are presented which incorporate parametric and ordinary excitations to generate electric power. The performance of each design is examined through experimental investigations.

Designing Wind Turbines for Areas With Low Wind Speeds

2014 ◽  
Author(s):  
Mohammed S. Mayeed ◽  
Adeel Khalid
Keyword(s):  
Energy Consumption ◽  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbines ◽  
Small Scale ◽  
Wind Speeds ◽  
Low Wind Speed ◽  
Average Wind ◽  
The World ◽  
Low Wind Speeds

Today’s wind turbines are designed in a wide range of vertical and horizontal axis types. In this study, several wind turbines are designed for low wind speed areas around the world mainly for domestic energy consumption. The wind speed range of 4–12 mph is considered, which is selected based on the average wind speeds in the Atlanta, GA and surrounding areas. These areas have relatively low average wind speeds compared to various other parts of the United States. Wind energy has been identified as an important source of renewable energy. Traditionally wind energy utilization is limited to areas with higher wind speeds. In reality a lot of areas in the world including Atlanta, GA., have low average wind speeds and demand high energy consumption. In most cases, wind turbines are installed in remote offshore or away from habitat locations, causing heavy investment in installation and maintenance, and loss of energy transfer over long distances. Therefore, the main focus of this study is to extract wind energy domestically at low wind speeds. A few more advantages of small scale wind turbines include reduced visibility, less noise and reduced detrimental environmental effects such as killing of birds, when compared to traditional large turbines. With the latest development in wind turbine technology it is now possible to employ small scale wind turbines that have much smaller foot print and can generate enough energy for small businesses or residential applications. The low speed wind turbines are typically located near residential areas, and are much smaller in sizes compared to the large out of habitat wind turbines. In this study, several designs of wind turbines are modeled using SolidWorks. Virtual aerodynamic analysis is performed using SolidWorks Flow simulation software, and then optimization of the designs is performed based on maximizing the starting rotational torque and acceleration. From flow simulations, forces on the wind turbine blades and structures are calculated, and used in subsequent stress analysis to confirm structural integrity. Critical insight into the low wind speed turbine design is obtained using various configurations and the results are discussed. The study will help identify bottlenecks in the practical and effective utilization of low speed wind energy, and help devise possible remedial plans for the areas around the globe that get low average wind speeds.

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