Annual Average Wind Speed Research Articles

Wind Turbine Asynchronous Generator Control Algorithms

The aspects of mass usage of 7-15 meters diameter wind turbines (WT) on 5-15kW uninterrupted power supply in the continental region conditions at 3-10 m/s dominant wind speeds and 4-6 m/s average annual wind speed is discussed. A method of generating the desired power characteristics of WT, taking into account the differential chart of wind flow distribution and electric energy consumption structure is prposed. We have studied the control algorithms of frequency-controlled asynchronous generator wind turbine to provide the braking of rotor in the modes of partial loading, stabilizing the nominal power and full stop. The approach is illustrated by the analysis of combined mechanical characteristics of the wind turbine and the generator. We discuss the control system of a wind turbine with gain-frequency control of the generator and automatic distribution of generated power between the consumers of self-contained power grid and the static energy storage. We propose the methods of optimization for the generator operating modes based on the of three phase electromechanical converters generalized energy flow theory.

Techno-economic analysis of a stand-alone hybrid renewable energy system with hydrogen production and storage options

In the present study, a hybrid renewable energy system using hydrogen energy as energy storage option is conceptually modeled for the Bozcaada Island in Turkey. The system is investigated from the techno-economic point of view. The Hybrid Optimization Model for Electric Renewable (HOMER) tool is used to define the optimum size of the equipment based on the geographical and meteorological data of the island. The HOMER uses the net present cost (NPC) method while ranking the system suitability. Also, the cost of energy (COE) is calculated with the total annual cost (ACT). The study considers two scenarios, which are only wind turbine and wind turbine/PV hybrid systems. Using the wind turbine/PV array system, instead of wind turbine only, decreases the NPC from $14,624,343 to $11,960,698. Also, it decreases the hydrogen tank capacity to 400 kg and hence affects other equipment size and NPC. So, the COE varies between $1.016/kWh and $0.83/kWh. According to this, the optimum system components are defined as PV array-300 kW, wind turbine (E33x2), fuel cell-100 kW, converter-150 kW, electrolyzer-200 kW and hydrogen tank-400 kg to supply a 1875 kWh/d primary load. Furthermore, the effects of some parameters and the equipment on NPC are examined. Increasing potential of the renewable energy sources, such as annual average wind speed or solar radiation, decreases both COE and NPC. While the annual average solar radiation increases to 5 kWh/m2/d, the NPC and COE decrease to $11,673,704 and $0.81/kWh. Likewise, an increase in the annual average wind speed will decrease the costs to $11,452,712 and $0.795/kWh, respectively. Also, increasing the real interest i, to 5% increases the COE to $1.043/kWh, as expected.

Use of Vortex Wind Power Plant in the Climatic Conditions of Middle Volga - Stator Calculation Method

This article estimates the potential of using wind power in Samara Region, and proves promising use of vortex wind power plant (VWPP) in areas with annual average wind speed less than 6 m / s. The present article also provides a semi-empirical method for calculating VWPP which was created in consideration of the Ranque vortex effect theory and the features of hypothesis of the vortex interference in rotational flows.

Transport of black carbon aerosols from non-local sources: A case study in Shanghai

Black carbon (BC) aerosol mass carried by winds of varying directions from non-local sources was estimated based on hourly measured data of BC mass concentration (CBC) and meteorological parameters from January 2008 to December 2012 in Shanghai, and the relationship between annual average CBC and wind speed was analyzed. The results show that the annual average CBC decreased with wind speed for speeds exceeding 0.3m/s. The relationship between the two was determined by a linear fit with correlation coefficient 0.88. Assuming BC aerosol mass of non-local sources transported by a southeast wind was zero, annual average BC concentrations (μg/m3) carried by winds of variable direction were 1.99 (southwest), 1.95 (west), 1.15 (northwest), 0.54 (south), 0.39 (north), 0.01 (northeast), and 0.01 (east). BC aerosol mass of non-local sources transported by wind to Shanghai was about 6404.05t per year, among which the total contribution of southwest, west, and northwest winds was nearly 84%. The aerosol mass transported to Shanghai in winter accounted for 35% that of the entire year, and was greater than that of the other seasons.

Geographical distribution of left ventricular Tei index based on principal component analysis

To provide a scientific standard of left ventricular Tei index for healthy people from various region of China, and to lay a reliable foundation for the evaluation of left ventricular diastolic and systolic function. The correlation and principal component analysis were used to explore the left ventricular Tei index, which based on the data of 3 562 samples from 50 regions of China by means of literature retrieval. Th e nine geographical factors were longitude(X₁), latitude(X₂), altitude(X₃), annual sunshine hours (X₄), the annual average temperature (X₅), annual average relative humidity (X₆), annual precipitation (X₇), annual temperature range (X₈) and annual average wind speed (X₉). ArcGIS soft ware was applied to calculate the spatial distribution regularities of left ventricular Tei index. There is a significant correlation between the healthy people's left ventricular Tei index and geographical factors, and the correlation coefficients were -0.107 (r₁), -0.301 (r₂), -0.029 (r₃), -0.277 (r₄), -0.256(r₅), -0.289(r₆), -0.320(r₇), -0.310 (r₈) and -0.117 (r₉), respectively. A linear equation between the Tei index and the geographical factor was obtained by regression analysis based on the three extracting principal components. The geographical distribution tendency chart for healthy people's left Tei index was fitted out by the ArcGIS spatial interpolation analysis. The geographical distribution for left ventricular Tei index in China follows certain pattern. The reference value in North is higher than that in South, while the value in East is higher than that in West.

Research the Influencing Factors of the Low Wind Speed Wind Turbine Fatigue Loads

This paper analyzes three main factors (turbulence intensity, air density, annual average wind speed ) that influence the low wind speed wind turbine fatigue loads, In order to analyze the influence of each main parameters how to affect the fatigue load of low wind speed wind turbine, using a 2000kW wind turbine as an example on the simulation test , 3 turbulence, 4 air density and 7 annual average wind speed were employed. The results show that, with the air density, turbulence intensity and the annual average wind speed increases, the wind turbine of fatigue load increase in rule approximately. Based on the above rule, it can reduce fatigue loads and prolong the life of wind turbine in design optimization of low wind speed wind turbine and sit choice.

Heliostat drive unit design considerations – Site wind load effects on projected fatigue life and safety factor

A parametric analysis shows the importance of various effects on heliostat drive unit life, including wind conditions, angles of attack, size, and endurance limits and how these affect predicted safety factors required in terms of fatigue damage. Endurance limit effects are shown to be critical, including “wear and tear” reductions from field exposure and operation, which significantly reduce remaining life. Low safety factors are shown to pose a risk of achieving 30-year life, especially when site wind conditions are considered. Gusts significantly increase the required safety factor, even if they occur for only 10% of the time. Seasonal wind speed variations are also shown to be important, in that speeds during a 3-month period, typically in the Spring, that are above the annual average require a significantly higher safety factor than the predicted value based on the annual average alone. Sites with low annual average wind speeds are shown to be preferable. Having heliostats fully stowed at lower wind speeds than legacy specifications of 50mph increase life and reduce safety factors required.

Potential for wind energy generation in Piracicaba, SP, Brazil

Wind power has gained space in Brazil's energy matrix, being a clean source and inexhaustible. Therefore, it becomes important to characterize the wind potential of a given location, for future applications. The main objective of the present study was to estimate the wind energy potential in Piracicaba, SP, Brazil. The wind speed data were collected by an anemometer installed at the Meteorological Station Luiz de Queiroz College of Agriculture, Piracicaba-SP. The wind speed variability was represented by the Weibull frequency distribution, a probability density function of two parameters (k and c). The parameters k and c were used to correlate the Gamma function with the annual average wind speed, the variance and power mean density. A wind profile was made to evaluate the behavior of historical average speeds at higher altitudes measured by anemometer, to estimate the gain in power density. The values of k for all heights were close to 1 which corresponds to a wind regime highly variable, and c values were also low representing a low average speed of the location. The location was characterized as being unfavorable for the application of wind turbines for power generation.

Wind speed estimation using multilayer perceptron

Wind speed knowledge is prerequisite in the siting of wind turbines. In consequence the wind energy use requires meticulous and specified knowledge of the wind characteristics at a location.This paper presents a method for determining the annual average wind speed at a complex terrain site by using neural networks, when only short term data are available for that site. This information is useful for preliminary calculations of the wind resource at a remote area having only a short time period of wind measurements measurement in a site. Artificial neural networks are useful for implementing non-linear process variables over time, and therefore are a useful tool for estimating the wind speed. The neural network used is multilayer perceptron with three layers and the supervised learning algorithm used is backpropagation. The inputs used in the neural network were wind speed and direction data from a single station, and the training patterns used correspond to sixty days data. The results obtained by simulating the annual average wind speed at the selected site based on data from nearby stations with correlation coefficients above 0.5 were satisfactory, compared with actual values. Reliable estimations were obtained, with errors below 6%.

Assessment of the Prediction Capacity of a Wind-Electric Generation Model

Harnessing the wind resource requires technical development and theoretical understanding to implement reliable predicting toolkits to assess wind potential and its economic viability. Comprehensive toolkits, like RETScreen®, have become very popular, allowing users to perform rapid and comprehensive pre-feasibility and feasibility studies of wind projects among other clean energy resources. In the assessment of wind potential, RETScreen® uses the annual average wind speed and a statistical distribution to account for the month-to-month variations, as opposed to hourly- or monthly-average data sets used in other toolkits. This paper compares the predictive capability of the wind model in RETScreen® with the effective production of wind farms located in the region of Ontario, Canada, to determine which factors affect the quality of these predictions and therefore, to understand what aspects of the model may be improved. The influence of distance between wind farms and measuring stations, statistical distribution shape factor, wind shear exponent, annual average wind speed, temperature and atmospheric pressure on the predictions is assessed. Based on the results, a maximum distance radius of 30km from the measuring station to the project site is recommended when using RETScreen toolkit. The wind shear exponent came off as the second most influential parameter after the annual average wind speed in terms of the prediction of accurate Power Generation. It was found that the former must be carefully chosen to match the type of terrain in order to achieve up to a 4-9% improvement in the current prediction capability of the software.

河西绿洲边缘积沙带形成的典型相关因子

PDF HTML阅读 XML下载 导出引用 引用提醒 河西绿洲边缘积沙带形成的典型相关因子 DOI: 10.5846/stxb201301210123 作者: 作者单位: 甘肃省治沙研究所 甘肃兰州,甘肃省治沙研究所 甘肃兰州,甘肃省治沙研究所 甘肃兰州;甘肃省荒漠化防治重点实验室 甘肃兰州,甘肃省治沙研究所 甘肃兰州;甘肃省荒漠化防治重点实验室 甘肃兰州,甘肃省治沙研究所 甘肃兰州;甘肃省荒漠化防治重点实验室 甘肃兰州,甘肃省治沙研究所 甘肃兰州;甘肃省荒漠化防治重点实验室 甘肃兰州,甘肃省治沙研究所 甘肃兰州;甘肃省荒漠化防治重点实验室 甘肃兰州,甘肃省治沙研究所 甘肃兰州;甘肃省荒漠化防治重点实验室 甘肃兰州,甘肃省治沙研究所 甘肃兰州,甘肃省治沙研究所 甘肃兰州 作者简介: 通讯作者: 中图分类号: S727.23 基金项目: 国家自然科学基金（41261102）；国家973前期（2011CB411912） Canonical correlation factors causing the formation of accumulated sand-belts along the oasis fringe in Hexi corridor Author: Affiliation: Gansu Desert Control Research Institute,,,,,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:绿洲边缘积沙带的形成因素及其生态效应是一个新的科学问题。为了研究河西绿洲边缘积沙带的形成原因，运用方差分析、相关分析以及典型相关分析等方法，对河西绿洲边缘积沙带的21个样点的观测资料进行了分析。结果表明：河西绿洲边缘积沙带的分布趋势大致为东高西低、东宽西窄，大部分地段目前处于稳定阶段；积沙带上的优势种植物以天然柽柳最多，不同优势种植物的积沙带的迎风坡植被盖度及植被纯盖度差异较显著。典型相关分析结果表明：积沙带的高度和宽度是降水量、到沙源的距离、背风坡植被盖度和年平均风速等气候环境因子共同作用的结果。积沙带的生态效应：一是自身作为一种障碍物的防护作用，二是阻截、减少流沙流沙进入农田的作用。 Abstract:Accumulated sand-belts refer to those formed along the oasis fringe, especially at the upwind location, due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China, a lot of trees have been planted for desertification combating in northwest and north China, thus, accumulated sand-belts were formed at the upwind location. The formation and the ecological effects of the accumulated sand-belts along the oasis fringe is a new scientific concern. To study the formation causes of these belts in Hexi corridor, 21 samples were selected, and the height/width of the belts, as well as the vegetation, soil, soil moisture and climatic factors were investigated. This paper analyzed the correlation between the height/width of the belts and the vegetation, soil, soil moisture and climatic factors using the methods of variance analysis, correlation analysis and canonical correlation analysis. The results indicate that: the accumulated sand-belts take a trend of being high and wide in the east whereas low and narrow in the west, and most of the parts tend to be stable; the species on the belts are dominated by Tamarix austromongolica, the vegetation cover and the pure vegetation cover of different dominant species on the leeward slope of the accumulated sand-belts vary significantly. The canonical correlation analysis shows that: the height and width of accumulated sand-belt is the interaction of precipitation, distance to the sand source, leeward vegetation cover and annual average wind speed. Moreover, the height of accumulated sand-belts are negatively correlated to the soil moisture at the depth of 30-50cm, air humidity and leeward vegetation cover, and the width of the belts is also negatively correlated with the distance to the sand source. The ecological effects of the accumulated sand-belts are both positive (stopping sands from moving into farmland, protective role as an obstacle) and negative (when the belts decay and activate one day, they will become the new sand sources). At present, there are no signs showing the negative effects of the belts. The ecological effects of the accumulated sand-belts are: firstly the protective role as an obstacle, and secondly to intercept and reduce the sands moving into farmlands. Whether by use single correlation analysis method or by use canonical correlation analysis method, the results show that the accumulated sand-belt height and width are closely related with annual precipitation,by use principal factor analysis method,the results also show that the contribution of annual precipitation in climatic and environmental factors in the maximum rate. In Hexi oasis edge, accumulated sand-belt distribution trends roughly east accumulated sand-belt higher and wider than west accumulated sand-belt, accumulated sand-belts discontinuous distribution with oasis distribution, most of the area is currently in a stable stage,if as long as no damage, then after 70-80 years that accumulated sand-belt is still not activated to cause harm. 参考文献 相似文献 引证文献

Dynamical Downscaling of Climate Change Impacts on Wind Energy Resources in the Contiguous United States by Using a Limited-Area Model with Scale-Selective Data Assimilation

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.

我国西南地区风速变化及其影响因素

PDF HTML阅读 XML下载 导出引用 引用提醒 我国西南地区风速变化及其影响因素 DOI: 10.5846/stxb201305141051 作者: 作者单位: 西北师范大学地理与环境科学学院,西北师范大学地理与环境科学学院,西北师范大学地理与环境科学学院,西北师范大学地理与环境科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目（41161028） Wind speed changes and its influencing factors in Southwestern China Author: Affiliation: College of Geography and Environmental Science,Northwest Normal University,College of Geography and Environmental Science,Northwest Normal University,College of Geography and Environmental Science,Northwest Normal University,College of Geography and Environmental Science,Northwest Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:基于110个台站日风速观测资料，对我国西南地区1969-2009年风速时空变化及其影响因素进行研究，结果表明：1969-2009年西南地区平均风速以0.24 m s-1 10a-1的速率显著降低，其中1969-2000年平均风速以0.37 m s-1 10a-1速率降低，而2001-2009年却以0.55 m s-1 10a-1的速率升高，各季节、非季风和季风期风速变化趋势与年序列相似。空间分布上，1969-2009年风速降低台站主要位于高海拔区，降低幅度呈现西高东低趋势。1969-2000年风速降低台站主要位于西藏高原、横断山区和云南高原。2001-2009年风速增加台站主要位于云南高原、横断山区和四川盆地。风速这种变化趋势一方面受大气环流影响，西风环流和季风环流风速的减弱可能是2000年之前风速降低的重要原因，而纬向风的加强则对2000年以来风速增强有重要贡献。另一方面，区域变暖是风速降低的关键诱因。 Abstract:Based on the daily wind speed observation data of 110 stations,this paper studies in temporal changes of wind speed and its influencing factors in Southwest China from 1969 to 2009. The results show that there was a statistically significant decrease of 0.24 m s-1 10a-1 in the annual mean wind speed in Southwestern China from 1969 to 2009. The annual average wind speed of 0.37 m s-1 10a-1 rate decreased from 1969 to 2000,while the wind speed increased of 0.55 m s-1 10a-1 from 2001 to 2009. The pattern of seasonal changes of wind speed was similar. From 1969 to 2009,there was a significant reduced in wind speed,the wind speed decreased from 1969 to 2000,while the wind speed increased from 2001 to 2009. On the spatial distribution of it,from 1969 to 2009 the annual wind speed reducing stations were mainly located in high altitude area,reducing the magnitude of the performance gradually decreasing from west to east,reflecting the impact of the terrain. From 1969 to 2000,the wind speed reducing stations were mainly located in the Tibetan Plateau,Hengduan Mountains and the Yunnan Plateau,the wind speed increases stations were located in Guizhou Plateau and the Sichuan Basin. From 2001 to 2009,the wind speed increases stations were mainly located in Yunnan Plateau,Hengduan Mountains and the Sichuan Basin,reducing wind stations were mainly located in the Tibetan Plateau and Guizhou Plateau. On the one hand,the analysis have confirmed that the decreasing wind speed was caused mainly by the decreasing monsoon circulation and Westerlies from 1969 to 2000,and the strengthening latitudinal wind speed has made some contributions on the increasing wind speed after 2000. And what's more,the strengthening Tibetan monsoon has also made some contributions to wind change. On the other hand,regional warming was the key incentive for wind decreased. Warming temperatures rose,especially the lowest temperature significantly warming was the main reason that results in the decrease of wind speed,and further analysis revealed that weaken of the pressure gradient between the different latitudes is the key factor of reducing the wind speed. 参考文献 相似文献 引证文献

A hybrid wind/solar/diesel stand alone system optimisation for remote areas in Algeria

While Algeria has an important potential of wind and solar energies, their share in the primary energy supply is relatively low compared to the fossil energy. In this paper, we propose to carry out a techno-economical study of a hybrid stand alone system in order to draw the attention to the feasibility of such systems. For this purpose, sites of Hassi-R’mel and Adrar have been considered due to their important renewable potential. The chosen sites are located in the Algeria deserts and have an important solar potential. Concerning the wind potential, those two regions constitute the windiest regions in Algeria with an annual average wind speed of more than 6 m/s. The optimisation task is handled by the dedicated software HOMER which is a well known, robust and efficient tool to carry out such an activity. The two sites show promising potential with some characteristics distinguishing each region.

The Potential of a Mix of Renewable (PV/ Wind) Energy System for an Information and Communication Technology (ICT) Centre in a Rural Environment

The design is presented of an optimized mix of renewable (PV/Wind) energy system for an Information and Communication Technology (ICT) Center in Rural environments in Kauru (Kaduna State), Northern Nigeria with a daily load of 24 kwh d-1. Solar radiation and wind speed for the design of the system were obtained from the NASA Surface Meteorology and solar energy website at a location of 10° 39’ N latitude and 8° 09’ E longitude, with annual average solar radiation of 5.64 kWh m-2d-1 and annual average wind speed of 2.5 m s-1. The patterns of load consumption by the ICT Centre were studied and suitably modeled for optimization using the National Renewable Energy Laboratory’s Hybrid Optimization Model for Electric Renewables (HOMER) software. The proposed PV/Wind system was simulated using the model resulting in two different topologies: PV/Wind and PV only. From the simulation results, the PV/Wind system solution was considered to be the best energy option (solution) for the ICT Center. This optimization study indicates that energy requirements to provide electricity for an ICT center in Kauru with the least cost could be accomplished by a combination of 8 kW PV array, 1 unit 7.5 kW BWC Excel-R wind turbine, 1.5 kW inverter and 24 Hoppecke 24 OPzS 30000 batteries. The system configuration suggested also benefits from 33% excess electricity supply which allows for future ICT network expansion and power needs. This system also saves $6,341 for the project lifetime when compared with PV only system due to reduced number of battery unit. A detailed design and description of expected performance of the PV/Wind system are also presented.

Wind energy resource assessment of Izmit in the West Black Sea Coastal Region of Turkey

Abstract The wind energy potential of Izmit (41.19 N, 30.30 E), which is located in the West Black Sea Coastal Region of Turkey, is assessed with the statistical analysis of the gathered wind data at the 50-m height measurement mast covering the period of 06/2008-06/2009. The annual average wind speed is calculated as 6 m/s and the prevailing wind direction is ENE (60°). The Weibull distribution parameters of shape and scale factor are found as 2.03 and 6.73 m/s, respectively. The measured wind speed data are compared with the data of nearby meteorological stations and the results show that there is a considerable difference between the onsite measurements and the measurements of the meteorological stations. Moreover, a turbulence analysis is carried out and the turbulence intensity is negatively correlated with the normalized height from ground level with canopy height. The energy generation performances of three different wind turbines are evaluated by using the onsite wind speed measurements and the assessment shows that the capacity factor increase by a factor of two from 17% to 34% depending on the type of the turbine. Furthermore, an economic analysis is carried out for a 50 MW wind energy project for the potential site and the proposed project benefit/cost ratio is calculated as 8.

A Simplified Morphing Blade for Horizontal Axis Wind Turbines

The aim of designing wind turbine blades is to improve the power capture ability. Since rotor control technology is currently limited to controlling rotational speed and blade pitch, an increasing concern has been given to morphing blades. In this paper, a simplified morphing blade is introduced, which has a linear twist distribution along the span and a shape that can be controlled by adjusting the twist of the blade's root and tip. To evaluate the performance of wind turbine blades, a numerical code based on the blade element momentum theory is developed and validated. The blade of the NREL Phase VI wind turbine is taken as a reference blade and has a fixed pitch. The optimization problems associated with the control of the morphing blade and a blade with pitch control are formulated. The optimal results show that the morphing blade gives better results than the blade with pitch control in terms of produced power. Under the assumption that at a given site, the annual average wind speed is known and the wind speed follows a Rayleigh distribution, the annual energy production of wind turbines was evaluated for three types of blade, namely, morphing blade, blade with pitch control and fixed pitch blade. For an annual average wind speed varying between 5 m/s and 15 m/s, it turns out that the annual energy production of the wind turbine containing morphing blades is 24.5% to 69.7% higher than the annual energy production of the wind turbine containing pitch fixed blades. Likewise, the annual energy production of the wind turbine containing blades with pitch control is 22.7% to 66.9% higher than the annual energy production of the wind turbine containing pitch fixed blades.

MCP방법을 이용한 장기간 풍속 및 풍력에너지 변동 특성 분석

Wind resource data of short-term period has to be corrected a long-term period by using MCP method that Is a statistical method to predict the long-term wind resource at target site data with a reference site data. Because the field measurement for wind assessment is limited to a short period by various constraints. In this study, 2 different MCP methods such as Linear regression and Matrix method were chosen to compare the predictive accuracy between the methods. Finally long-term wind speed, wind power density and capacity factor at the target site for 20 years were estimated for the variability of wind and wind energy. As a result, for 20 years annual average wind speed, Yellow sea off shore wind farm was estimated to have 4.29% for coefficient of variation, CV, and -9.57%~9.53% for range of variation, RV. It was predicted that the annual wind speed at Yellow sea offshore wind farm varied within .

Environmental benchmarking of wind farms according to their operational performance

The combined use of Life Cycle Assessment and Data Envelopment Analysis (LCA + DEA methodology) facilitates the identification and quantification of the environmental consequences of operational inefficiencies when assessing multiple similar facilities. In this work, the LCA + DEA methodology was used to benchmark the operational and environmental performance of a sample of 25 wind farms located in Spain. Only four of the evaluated farms were found to be comparatively efficient. Input consumption levels that would turn inefficient wind farms into efficient facilities (i.e., target wind farms) were benchmarked. The environmental impacts linked to these target facilities were also benchmarked. Average reductions of 19–45% in the consumption of selected inputs were calculated, which resulted in average impact reductions of 18–29% for a selection of environmental impact categories. The potential economic savings associated with the target wind farms were also estimated. Finally, potential relationships between efficiency and annual power generation, location or average wind speed were discussed.

Appraising the viability of wind energy conversion system in the Peninsular Malaysia

To harvest the wind energy resource for power production, it is crucially important to carry out a preliminary study to understand the site-specific nature of wind at the intended site. Such knowledge is required to estimate the performance of a wind energy project in the area. This study investigates the wind energy potential for production of electric power in the Peninsular Malaysia. Wind speed data of six selected sites across the country collected over a period of 10–20years are employed for the study. A statistical analysis of the wind speeds is carried out using the Weibull distribution model. Six identified commercially available wind turbines with rated capacity ranging from 20kW to 1500kW, with different speed parameters are simulated at the selected locations. Of the six sites evaluated in this paper, it is revealed that Mersing, having the highest monthly average wind speed and consequently the most viable, produces an average power density of 57.58W/m2 with a capacity factor of only 4.39%. This is equivalent to 378MWh energy production per annum at a levelised cost of 22cents per kWh. This study also shows that the standard deviation of the average monthly wind speeds is a better factor than the average annual wind speed for ranking of selected sites in terms of annual energy production. Overall, the results obtained from this investigation show that large-scale wind energy is not viable in Malaysia due to weak wind regimes; however, small-scale wind energy system may be economically viable in a few regions most especially when the recently launched feed-in tariff in the country is extended to wind energy.