Wind Speed Change and Influence on Wind Energy in Recent 50 Years over Hexi Corridor

2014 ◽  
Vol 1070-1072 ◽  
pp. 284-290
Author(s):  
Yao Zong Zhang ◽  
Bo Zhang ◽  
Yan Yan Liu

Based on wind speed data of 13 meteorological stations in 1958-2012,Mann-Kendall nonparametric test methods was been used to study on wind speed changes in Hexi Corridor.Spatial and temporal characteristics of seasonal and monthly wind speed changes was examined. (1) The maximum wind speed appeared in the higher elevations of study area, such as Wushaoling and Mazongshan station. From east to west mean wind speed increased in Hexi Corridor.For nearly 50 years wind speed had showed decreasing trend. (2)In each season Spring with an maximum mean wind speed was 3.4m/s,the Summer mean wind speed was 2.9 m/s,Autumn mean wind speed was 2.6 m/s,the mean Winter wind speed was 2.8m/s.The seasonal wind speed mainly had decline trend, each station.has different characteristics trends (3) Mean wind speed in each month was greater than 2.5m/s,maximum monthly wind speed appeared in April was 3.5m/s,the minimum wind speed appeared in the September-October was 2.53m/s,the wind speed in March,April and May was greater than the November month,December,January.In addition to Mazongshan and Wushaoling,other station monthly wind speed showed a decreasing trend.Monthly mean wind speed in Jiuquan,Dingxin and Zhangye was slow decreasing trend.Anxi,Yumen wind decreasing trend were more obvious.(4)Wind decreasing trend will have a significant impact on wind energy, wind speed changes and wind energy should be evaluated in the future.

2015 ◽  
Vol 17 (2) ◽  
pp. 418-425

<p>Today&#39;s world requires a change in how the use of different types of energy. With declining reserves of fossil fuels for renewable energies is of course the best alternative. Among the renewable energy from the wind can be considered one of the best forms of energy can be introduced. Accordingly, most countries are trying to identify areas with potential to benefit from this resource.</p> <p>The aim of this study was to assess the potential wind power in Sahand station of Iran country. Hourly measured long term wind speed data of Sahand during the period of 2000-2013 have been statistically analyzed. In this study the wind speed frequency distribution of location was found by using Weibull distribution function. The wind energy potential of the location has been studied based on the Weibull mode. The results of this study show that mean wind speed measured at 10 m above ground level is determined as 5.16 m/s for the studied period. This speed increases by, respectively, 34.78 % and 41.21 %, when it is extrapolated to 40 and 60 m hub height.</p> <div> <p>Long term seasonal wind speeds were found to be relatively higher during the period from January to September. At the other hand, higher wind speeds were observed between the period between 06:00 and 18:00 in the day. These periods feet well with annual and daily periods of maximum demand of electricity, respectively.&nbsp;</p> </div> <p>&nbsp;</p>


Wind is a renewable energy resource by nature. It is clean, abundant, inexhaustible and environmentally friendly. Essentially, this study investigated the prospects of wind energy for power generation in University of Benin. Wind data from Jan 31st – Dec 31st 2013 (at 10m height) was collected from National Centre for Energy and Environment, University of Benin. Accordingly, the annual and monthly wind speed and density are estimated using the 2- parameter Weibull probability density function. From the analysis, results obtained shows that the highest mean wind speed of 1.975m/s occurred in March and the lowest monthly mean speed of 0.977m/s occurred in November. Also, the annual mean wind speed is 1.496m/s while the annual mean power density based on Weibull distribution function is 2.692W/m2 . Further results shows that the mean annual most probable wind speed and wind speed carrying maximum energy are 1.535m/s and 1.761m/s respectively. Thus, it is recommended that the institution can tap on the available wind power potential to augment its power supply.


2019 ◽  
Vol 8 (3) ◽  
pp. 267-273 ◽  
Author(s):  
Daoudi Mohammed ◽  
Ait Sidi Mou Abdelaziz ◽  
Elkhomri Mohammed ◽  
Elkhouzai Elmostapha

This paper presents the wind energy potential at 10 m during a period of 09 years (2009-2017) in the province of Zagora using the Weibull distribution method. Extrapolation of the 10 m data, using the power Law, has been used to determine the wind data at heights of 30 m; 50 m and 70 m. The objective is to evaluate the most important characteristics of wind energy in the studied site . The statistical attitudes permit us to estimate the mean wind speed, the wind speed distribution function and the mean wind power density in the site at the height of 30 m; 50 m and 70 m. From the primary evaluation indicate that the annual energy output and capacity factor increases with increasing the wind speed, it can obtain about 2.62 GWh/year, that is acceptable quantity for the wind energy. ©2019. CBIORE-IJRED. All rights reserved


2021 ◽  
Vol 16 (4) ◽  
pp. 641-650
Author(s):  
Derradji Mederreg ◽  
Mohamed Salmi ◽  
Maouedj Rachid ◽  
Hijaz Ahmad ◽  
Giulio Lorenzini ◽  
...  

Details on the wind potential during a period of about thirteen years in Algeria is given in the present work. The inspection is performed for sixteen regions covering almost all the territory of the country. The density of the mean wind power is determined for the different regions. The maps of annual and seasonal wind energy resources are also established. The characteristics of the wind velocity, as well as the potential of wind power, are determined by the Weibull distribution. From the given results, the highest values of annual mean wind speed and the annual mean wind power density are found in Adrar (P10 = 283.12 W/m2 and P50 = 646.91 W/m2), while the lowest values are observed in Skikda (P10 = 40.61 W/m2 and P50 = 115.51 W/m2, respectively).


2001 ◽  
Vol 123 (4) ◽  
pp. 339-345 ◽  
Author(s):  
P. J. Moriarty ◽  
A. J. Eggers, ◽  
K. Chaney ◽  
W. E. Holley

The effects of rotor scale and control system lag were examined for a variable-speed wind turbine. The scale study was performed on a teetered rotor with radii ranging between 22.5m and 33.75m. A 50% increase in radius more than doubled the rated power and annual energy capture. Using blade pitch to actively control fluctuating flatwise moments allowed for significant reductions in blade mass for a fixed fatigue life. A blade operated in closed-loop mode with a 33.75m radius weighed less than an open-loop blade with a 22.5m radius while maintaining the same fatigue life of 5×109 rotations. Actuator lag reduced the effectiveness of the control system. However, 50% reductions in blade mass were possible even when implementing a relatively slow actuator with a 1 sec. time constant. Other practical limits on blade mass may include fatigue from start/stop cycles, non-uniform turbulence, tower wake effects, and wind shear. The more aggressive control systems were found to have high control accelerations near 60 deg/s2, which may be excessive for realistic actuators. Two time lags were introduced into the control system when mean wind speed was estimated in a rapidly changing wind environment. The first lag was the length of time needed to determine mean wind speed, and therefore the mean control settings. The second was the frequency at which these mean control settings were changed. Preliminary results indicate that quickly changing the mean settings (every 10 seconds) and using a moderate length mean averaging time (60 seconds) resulted in the longest fatigue life. It was discovered that large power fluctuations occurred during open-loop operation which could cause sizeable damage to a realistic turbine generator. These fluctuations are reduced by one half or more when aerodynamic loads are actively controlled.


Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 776 ◽  
Author(s):  
Ziqi Zhao ◽  
Lidu Shen ◽  
Liguang Li ◽  
Hongbo Wang ◽  
Bao-Jie He

Studies on urban ventilation indicate that urban ventilation performance is highly dependent on urban morphology. Some studies have linked local-scale urban ventilation performance with the local climate zone (LCZ) that is proposed for surface temperature studies. However, there is a lack of evidence-based studies showing LCZ ventilation performance and affirming the reliability of using the LCZ classification scheme to demonstrate local-scale urban ventilation performance. Therefore, this study aims to analyse LCZ ventilation performances in order to understand the suitability of using the LCZ classification scheme to indicate local-scale urban ventilation performance. This study was conducted in Shenyang, China, with wind information at 16 weather stations in 2018. The results indicate that the Shenyang weather station had an annual mean wind speed of 2.07 m/s, while the mean wind speed of the overall 16 stations was much lower, only 1.44 m/s in value. The mean wind speed at Shenyang weather station and the 16 stations varied with seasons, day and night and precipitation conditions. The spring diurnal mean wind was strong with the speeds of 3.56 m/s and 2.21 m/s at Shenyang weather station and the 16 stations, respectively. The wind speed (2.21 m/s at Shenyang weather station) under precipitation conditions was higher than that (1.75 m/s at Shenyang weather station) under no precipitation conditions. Downtown ventilation performance was weaker than the approaching wind background, where the relative mean wind speed in the downtown area was only 0.53, much less than 1.0. The downtown ventilation performance also varied with seasons, day and night and precipitation conditions, where spring diurnal downtown ventilation performance was the weakest and the winter nocturnal downtown ventilation performance was the strongest. Moreover, the annual mean wind speed of the 16 zones decreased from the sparse, open low-rise zones to the compact midrise zones, indicating the suitability of using LCZ classification scheme to indicate local-scale urban ventilation performance. The high spatial correlation coefficients under different seasons, day and night and precipitation conditions, ranging between 0.68 and 0.99, further affirmed that LCZ classification scheme is also suitable to indicate local-scale urban ventilation performance, despite without the consideration of street structure like precinct ventilation zone scheme.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Bin Liu ◽  
Katelyn B. Costa ◽  
Lian Xie ◽  
Fredrick H. M. Semazzi

By using a limited-area model (LAM) in combination with the scale-selective data assimilation (SSDA) approach, wind energy resources in the contiguous United States (CONUS) were downscaled from IPCC CCSM3 global model projections for both current and future climate conditions. An assessment of climate change impacts on wind energy resources in the CONUS region was then conducted. Based on the downscaling results, when projecting into future climate under IPCC’s A1B scenario, the average annual wind speed experiences an overall shift across the CONUS region. From the current climate to the 2040s, the average annual wind speed is expected to increase from 0.1 to 0.2 m s−1over the Great Plains, Northern Great Lakes Region, and Southwestern United States located southwest of the Rocky Mountains. When projecting into the 2090s from current climate, there is an overall increase in the Great Plains Region and Southwestern United States located southwest of the Rockies with a mean wind speed increase between 0 and 0.1 m s−1, while, the Northern Great Lakes Region experiences an even greater increase from current climate to 2090s than over the first few decades with an increase of mean wind speed from 0.1 to 0.4 m s−1.


2018 ◽  
Vol 21 (15) ◽  
pp. 2217-2226 ◽  
Author(s):  
YC Kim ◽  
Y Tamura ◽  
A Yoshida ◽  
T Ito ◽  
W Shan ◽  
...  

The general characteristics of aerodynamic vibrations of a solar wing system were investigated through wind tunnel tests using an aeroelastic model under four oncoming flows. In total, 12 solar panels were suspended by cables and orientated horizontally. Distances between panels were set constant. Tests showed that the fluctuating displacement increases proportionally to the square of the mean wind speed for all wind directions in boundary-layer flows. Larger fluctuating displacements were found for boundary-layer flows with larger power-law indices. Under low-turbulence flow, the fluctuating displacement increased proportionally to the square of the mean wind speed for wind directions between 0° and 30°, but an instability vibration was observed at high mean wind speed for wind directions larger than 40°. And when the wind direction was larger than 60°, a limited vibration was observed at low mean wind speed and the instability vibration was also observed at high mean wind speed. Fluctuating displacements under grid-generated flow showed a similar trend to that of the boundary-layer flows, although the values became much smaller.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3986 ◽  
Author(s):  
Florin Onea ◽  
Andrés Ruiz ◽  
Eugen Rusu

The main objective of the present work is to provide a comprehensive picture of the wind conditions in the Spanish continental nearshore considering a state-of-the-art wind dataset. In order to do this, the ERA5 wind data, covering the 20-year time interval from 1999 to 2018, was processed and evaluated. ERA stands for ’ECMWF Re-Analysis’ and refers to a series of research projects at ECMWF (European Centre for Medium-Range Weather Forecasts) which produced various datasets. In addition to the analysis of the wind resources (reported for a 100 m height), the performances of several wind turbines, ranging from 3 to 9.5 MW, were evaluated. From the analysis of the spatial maps it was observed that the Northern part of this region presents significant wind resources, the mean wind speed values exceeding 9 m/s in some locations. On the other hand, in regard to the Southern sector, more energetic conditions are visible close to the Strait of Gibraltar and to the Gulf of Lion. Nevertheless, from the analysis of the data corresponding to these two Southern nearshore points it was observed that the average wind speed was lower than 8 m/s in both summer and winter months. Regarding the considered wind turbines, the capacity factor did in general not exceed 20%—however, we did observe some peaks that could reach to 30%. Finally, it can be highlighted that the Northern part of the Spanish continental nearshore is significant from the perspective of extracting offshore wind energy, especially considering the technologies based on floating platforms. Furthermore, because of the clear synergy between wind and wave energy, which are characteristic to this coastal environment, an important conclusion of the present work is that the implementation of joint wind–wave projects might be effective in the Northwestern side of the Iberian nearshore.


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