Statistical analysis of wind speed and wind power potential of Port Elizabeth using Weibull parameters

2012 ◽  
Vol 23 (2) ◽  
pp. 30-38 ◽  
Author(s):  
Temitope R Ayodele ◽  
Adisa A. Jimoh ◽  
Josiah L. Munda ◽  
John T. Agee

This paper analyses wind speed characteristics and wind power potential of Port Elizabeth using statistical Weibull parameters. A measured 5–minute time series average wind speed over a period of 5 years (2005 - 2009) was obtained from the South African Weather Service (SAWS). The results show that the shape parameter (k) ranges from 1.319 in April 2006 to 2.107 in November 2009, while the scale parameter (c) varies from 3.983m/s in May 2008 to 7.390 in November 2009.The average wind power density is highest during Spring (September–October), 256.505W/m2 and lowest during Autumn (April-May), 152.381W/m2. This paper is relevant to a decision-making process on significant investment in a wind power project.

2019 ◽  
Vol 4 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Tyler C. McCandless ◽  
Sue Ellen Haupt

Abstract. Wind power is a variable generation resource and therefore requires accurate forecasts to enable integration into the electric grid. Generally, the wind speed is forecast for a wind plant and the forecasted wind speed is converted to power to provide an estimate of the expected generating capacity of the plant. The average wind speed forecast for the plant is a function of the underlying meteorological phenomena being predicted; however, the wind speed for each turbine at the farm is also a function of the local terrain and the array orientation. Conversion algorithms that assume an average wind speed for the plant, i.e., the super-turbine power conversion, assume that the effects of the local terrain and array orientation are insignificant in producing variability in the wind speeds across the turbines at the farm. Here, we quantify the differences in converting wind speed to power at the turbine level compared with a super-turbine power conversion for a hypothetical wind farm of 100 2 MW turbines as well as from empirical data. The simulations with simulated turbines show a maximum difference of approximately 3 % at 11 m s−1 with a 1 m s−1 standard deviation of wind speeds and 8 % at 11 m s−1 with a 2 m s−1 standard deviation of wind speeds as a consequence of Jensen's inequality. The empirical analysis shows similar results with mean differences between converted wind speed to power and measured power of approximately 68 kW per 2 MW turbine. However, using a random forest machine learning method to convert to power reduces the error in the wind speed to power conversion when given the predictors that quantify the differences due to Jensen's inequality. These significant differences can lead to wind power forecasters overestimating the wind generation when utilizing a super-turbine power conversion for high wind speeds, and indicate that power conversion is more accurately done at the turbine level if no other compensatory mechanism is used to account for Jensen's inequality.


Author(s):  
A. A. Yahaya ◽  
I. M. Bello ◽  
N. Mudassir ◽  
I. Mohammed ◽  
M. I. Mukhtar

One of the major developments in the technology today is the wind turbine that generates electricity and feed it directly to the grid which is used in many part of the world. The main purpose of this work is to determine the wind potential for electricity generation in Aliero, Kebbi state. Five years Data (2014-2018) was collected from the metrological weather station (Campell Scientific Model), the equipment installed at Kebbi State University of Science And Technology Aliero The data was converted to monthly and annual averages, and compared with the threshold average wind speed values that can only generate electricity in both vertical and horizontal wind turbines. The highest average wind speed 2.81 m/s was obtained in the month of January and the minimum average wind speed of 1.20 m/s in the month of October. Mean annual wind speed measured in the study area shows that there has been an increase in the wind speed from 2014 which peaked in 2015 and followed by sudden decrease to a minimum seasonal value in the year 2016. The highest wind direction is obtained from the North North-East (NNE) direction. From the results of wind power density it shows that we have highest wind power density in month of January and December with  0.8635 w/ m2 and 0.8295 w/ m2 respectively, while lowest wind power density in the month of October and September with 0.6780 w/ m2 and 0.6575 w/ m2  respectively. Result of the type Wind Turbine to be selected in the study area shows that the site is not viable for power generation using a horizontal wind turbine but the vertical wind turbine will be suitable for the generation of electricity.


2020 ◽  
Vol 15 (3) ◽  
pp. 205-215
Author(s):  
Raju Laudari ◽  
Bal Krishna Sapkota ◽  
Kamal Banskota

The paper assesses the feasibility of wind farming at the 16 sites scattered in different ecological regions of Nepal. The wind speed, the hourly and seasonal variation of wind, the wind-rose, the wind turbulence rate, the wind power density, the Weibull probability distribution and the frequency of the wind speed above cut in speed were computed. The average wind speed at all the sites was found to be higher during the dry season from March to May. The wind speed of the modern turbine for power generation at eight sites was found to be above cut-in speed. However, the wind power density was found to be good only at the two sites and fairly good at the six sites. More than 50 % time of a year at these eight sites had over 3.5 m/s wind speed. However, the turbulence rate at all the studied sites was found to be above the acceptance range of 25 %. Among the study sites, Kagbeni, Thini, Jumla, Ramechhap, Vorleni, Patan west, Hansapur and Baddanda were found to be technically feasible sites for wind energy generation in Nepal.


2019 ◽  
Author(s):  
Tyler C. McCandless ◽  
Sue Ellen Haupt

Abstract. Wind power is a variable generation resource and therefore requires accurate forecasts to enable integration into the electric grid. Generally, the wind speed is forecast for a wind plant and the forecasted wind speed is converted to power to provide an estimate of the expected generating capacity of the plant. The average wind speed forecast for the plant is a function of the underlying meteorological phenomena being predicted; however, the wind speed for each turbine at the farm is also a function of the local terrain and the array orientation. Conversion algorithms that assume an average wind speed for the plant, i.e., the super-turbine power conversion, assume that the effects of the local terrain and array orientation are insignificant in producing variability in the wind speeds across the turbines at the farm. Here, we quantify the differences in converting wind speed to power at the turbine level compared to a super-turbine power conversion for a hypothetical wind farm of 100 2-MW turbines as well as from empirical data. The simulations with simulated turbines show a maximum difference of approximately 3 % at 11 m s−1 with 1 m s−1 standard deviation of wind speeds and 8 % at 11 m s−1 with 2 m s−1 standard deviation of wind speeds as a consequence of Jensen’s Inequality. The empirical analysis shows similar results with mean differences between converted wind speed to power and measured power of approximately 68 kW per 2 MW turbine. However, using a random forest machine learning method to convert to power reduces the error in the wind speed to power conversion when given the predictors that quantify the differences due to Jensen’s Inequality. These significant differences can lead to wind power forecasters over-estimating the wind generation when utilizing a super-turbine power conversion for high wind speeds, and indicates that power conversion is more accurately done at the turbine level if no other compensatory mechanism is used to account for Jensen’s Inequality.


Author(s):  
Co Xuan Hoang ◽  
Linh Thi Hai Dang ◽  
Da Van Ta ◽  
Cuong Manh Dinh ◽  
Chinh Van Kim ◽  
...  

The construction of grid-connected wind power plants has increased sharply in Vietnam due to the rapid rise of energy demands. Previous studies of wind energy have shown that the wind potential of Vietnam compared to other countries of Southeast Asia and examined wind speed levels of each region of Vietnam. In this study, the annual electricity production (AEP), which is an important factor of project's cost and benefit calculation, was calculated for 13 study areas. A correlation equation between AEP and the average wind speed at 60m above ground level was also developed to estimate AEP where there exists only data of the annual average wind speed. Moreover, other resources of the development of grid-connected wind power were discussed in this research such as the Vietnamese supporting mechanism, international co-operation, turbine technology development, etc. The article then predicts the trend, and proposes some recommendations of developing grid-connected wind farms in Vietnam.


Author(s):  
Hamed H Pourasl ◽  
Vahid M Khojastehnezhad

The use of renewable energy as a future energy source is attracting considerable research interest globally. In particular, there is a significant growth in wind energy utilization during the last few years. This present study through a detailed and systematic literature survey assesses the wind energy potential of Kazakhstan for the first time. Using the Weibull distribution function and hourly wind speed data, the annual power and energy density of the sites are calculated. For the 50 sites considered in this study and at a height of 10 m above the ground, the annual average wind speed, the power density, and energy production of Kazakhstan range from 0.94–5.15 m/s, 4.50–169.34 W/m2 and 39.56–1502.50 kWh/m2/yr, respectively. It was found that Fort Sevcenko, Atbasar, and Akmola are the three best locations for wind turbine installation with wind power densities of 169.34, 135.30, and 111.51 W/m2, respectively. Fort Sevcenko demonstrates the highest potential for wind energy harvesting with an energy density of 1483.46 kWh/m2/yr. For the 15 commercial wind turbines, it was observed that the annual energy production of the selected turbines ranges between 3.8 GWh/yr in Petropavlovsk to 15.4 GWh/yr in Fort Sevcenko among the top six locations. The lowest and highest capacity factors correspond to the same sites with the values of 29.21% and 58.66%, respectively. Overall, it is the intention of this study to constitute a database for the users and developers of wind power in Kazakhstan.


2017 ◽  
Vol 36 (3) ◽  
pp. 923-929
Author(s):  
YN Udoakah ◽  
US Ikafia

The wind power potential and its viability for commercial energy production across two sites Eket (Latitude 4033’N & Longitude 7058’E) and Uyo (Latitude 5°18’53.7’’N & Longitude 7059’39.29’’E) in Akwa Ibom State were investigated. Using data obtained from the Nigeria Meteorological Agency (MIMET) for both locations for a period of four years (2010-2013), a statistical analysis was performed. The Weibull Distribution Function was used to determine the monthly and yearly wind speed. Resulting from the analysis, the values of the average wind speed, the average daily wind power, the shape parameter (k) and the scale factor(c) were obtained to be 6.7 m/s and 4.3 m/s, 0.91 MW and 0.25 MW, K~ 5.4 and 2.1, and c ≈ 8.8 m/s and 4.6 m/s respectively, for Eket and Uyo. Also, the annual electricity generation was projected to be 40.88 MWh& 10.80 MWh respectively, for Eket and Uyo. The Weibull distribution can be relied on for accurate prediction of wind energy output and resulting from the predicted values, Eket a coastal area was assessed to be viable for commercial wind power production compared to Uyo a non-coastal area. http://dx.doi.org/10.4314/njt.v36i3.36


2021 ◽  
Vol 22 (2) ◽  
pp. 149-160
Author(s):  
Alisher Safarov ◽  
Rasul Mamedov

This article presents theoretical and experimental studies of an improved vertical axis wind power device that generates electricity in areas with an average wind speed of 3.5-4.5 m/s. An algorithm has been developed for determining the geometrically optimal dimensions of the outer guiding surfaces to improve the efficiency of the device at low wind speeds. The device uses an AFPMG generator with opposite rotation of the stator and rotor. Matlab/Simulink and Solidworks were used to develop a mathematical and physical model of the wind power device. According to the results of the study, it was found that the developed wind power device can reach a rated power of 700 W at a wind speed of 8 m/s. The use of the device in areas with low wind speed is based on the possibility of increasing the efficiency of work by 5-10% at an average wind speed lower than that of other types of wind power devices. ABSTRAK: Artikel ini memaparkan kajian teori dan eksperimen berkenaan alat kuasa angin paksi menegak yang diperbaharui dan menghasilkan tenaga elektrik di kawasan kelajuan angin berpurata 3.5-4.5 m/s. Algoritma telah dibangunkan bagi menentukan dimensi optimum geometri permukaan berpandu luar dalam meningkatkan kecekapan peranti pada kelajuan angin yang kurang. Peranti ini menggunakan penjana AFPMG dengan putaran stator dan rotor yang berlawanan. Matlab/Simulink dan Solidworks digunakan bagi menghasilkan model matematik dan fizikal peranti tenaga angin. Berdasarkan dapatan kajian, didapati bahawa alat tenaga angin yang dibangunkan ini dapat mencapai daya kuasa sebanyak 700 W pada kecepatan angin 8 m/s. Penggunaan alat ini di kawasan kurang kelajuan angin berkemungkinan meningkatkan efisiensi purata kerja sebanyak 5-10% pada kelajuan angin rendah, iaitu lebih rendah daripada segala jenis peranti tenaga angin lain.


Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2796
Author(s):  
Andrzej Osuch ◽  
Ewa Osuch ◽  
Stanisław Podsiadłowski ◽  
Piotr Rybacki

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.


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