Assessment of solar and wind energy resources in Ethiopia. II. Wind energy

Using wind data from 21 meteorological stations with hourly or 3-hourly readings and 60 stations with monthly means, together with data from previous studies of neighbouring countries, a series of analyses were undertaken to illustrate the general availability of wind energy across Ethiopia. In order to calculate the wind energy density, firstly these 21 stations, along with 12 stations from neighbouring countries with hourly readings, were used to calculate the Weibull parameters, c and k. The Weibull distribution is shown to be a good approximation for the observed values in a majority of cases. Isopleths of the k values were then plotted, and from this the remaining 60 stations with monthly readings were then assigned k values. The wind energy density for each station was then calculated. Although the quantity of wind data is somewhat lacking, the results show that there is a potential for wind energy utilisation in some regions of Ethiopia.     

Compilation and evaluation of solar and wind energy resources in Sudan

A number of years worth of data concerning the solar radiation on a horizontal surface, sunshine duration and wind speed in Sudan have been compiled, evaluated and presented in this article.Measurements of global solar radiation on a horizontal surface at 16 stations for several years are compared with predictions made by several independent methods. In the first method the Angstrom formula was used to correlate relative global solar irradiance to the corresponding relative duration of bright sunshine.Regression coefficients are obtained and used for prediction of global solar irradiance. The predicted values were consistent with measured values (± 8.01% variation).In the second method, by Barbaro et al. [Solar Energy, 1978, 20, 431] sunshine duration and minimum air mass were used to drive an empirical correlation for the global radiation. The predicted values compared well with measured values (± 12% variation).The diffuse solar irradiance is estimated. The results of two formulas have close agreement. A radiation map of Sudan was prepared from the estimated radiation values. The annual daily mean global radiation ranges from 3.05 to 7.62 kW h m⁻² per day.Routine wind data from 70 stations were analyzed. Monthly averaged wind speed and average powers were determined for each station. The derived annual average speeds range from 1.53 to 5.07 m s⁻¹. Maximum extractable average wind powers were found to vary between 1.35 and 49.5 W m⁻². A wind map of Sudan was also prepared.Sudan possessed a relatively high abundance of sunshine and moderate wind speed. It is concluded that Sudan is blessed with abundant solar and wind energy.     

Assessment of utilization of wind energy resources in Nigeria

The study critically reviews the prospects and challenges of utilizing wind energy resources for power generation in Nigeria. The various initiatives by governments and researchers were surveyed and the nation is found to sit in the midst of enormous potential for wind harvest for power generation. The far northern states, the mountainous regions and different places of the central and south-eastern states were identified as good areas for wind harvest together with the offshore areas spanning from Lagos through Ondo, Ogun, Cross-Rivers to Rivers states along the Atlantic Ocean in the south–south. Despite this great potential and huge prospect, the country is found to still suffer from serious energy crises due to her over dependence on hydropower which also is susceptible to seasonal variation in the amount of water levels at dams. There is yet to be committed wind energy project for power generation on-going in the country. Several challenges bedeviling the development and utilization of wind energy resources were identified and suggestions highlighted to help pull the nation out of this lingering energy crisis.     

Solar and wind energy applications in Hawaii

The study on solar radiation and wind power applications is a facet of the total State of Hawaii solar assessment program. Engineering consultants, governmental authorities from the Department of Energy, State of Hawaii, and counties, technology assessments specialists, and buinessmen were contacter for input into this paper. The resultant late 1977 survey is a broad implementation plan highlighting seven typical applications—three solar, three wind and one combination.It was not the intention of this study to produce refined engineering/economic analyses. However a principal objective was to stimulate the development of solar energy by assisting in the first crucial steps of the planning process.This investigation selected projects which had potential for immediate implementation in the State of Hawaii. Variety in form of application, type of engineering analysis and location within the State was sought. To a large extent these basic premises were well met, as applications range from agriculture to aquaculture to tourism to education on three islands.In varying degrees, each project is recommended either for further study or immediate implementation. Some of the economics may be dubious, as would be the situation in most original applications. However, with appropriate governmental aid or incentives, these pilot projects could serve to improve economy of scale, spur associated developments, and in the long run, improve Hawaii's balance of trade.     

Solar and wind energy potential and utilization in Pakistan

Pakistan needs substantial amount of energy to develop its industry and to increase the agricultural productivity. The available indigenous energy resources are limited. The only option which the country has to pursue is renewable energy. This paper identifies the potentials of solar and wind energy. The prime sites for wind are coastal area, arid zone and hill terrains. Solar energy is abundant over most part of the country, maximum being received over Quetta valley.     

Numerical simulation of solar wind energy towers

A numerical investigation is conducted to study the performance of solar wind energy towers. The two-phase flow of air and water droplets in the tower is modeled following an Euler–Lagrange approach with air representing the continuous phase and water droplets the discrete phase. Results demonstrate that energy towers perform best in hot and dry environments. Water injection at the inlet to a tower increases the strength of the downdraft current with the rate of increase diminishing as the flow at exit approaches saturation. At a given water injection rate and tower diameter the downdraft strength increases as the height increases, while it is independent of the diameter at constant height. Energy analysis shows that for towers of low height the cost of electricity is expensive and commercially unfeasible, while it is cheap for towers of heights higher than 100?m.     

尖山子风电场风能资源评价

根据尖山子风电场1999年7月～2000年6月测风资料，对风电场的风能资源各参数进行了详细地计算和分析，从而得出尖山子地区风能资源丰富，适宜建设大型风电场，具有较大的开发利用价值的结论。     

实施太阳能建筑一体化打造太阳能建筑城

为贯彻《中华人民共和国可再生能源法》,邢台市委、市政府从邢台实际出发,于去年11月提出了实施"太阳能建筑一体化,打造太阳能建筑城"的发展战略,并于今年1月初,出台了邢台市政府1号文件,制定了发展目标和政策措施。短短几个月内,太阳能建筑一体化取得了突破性进展,赢得了市民的广泛称赞,引起了社会各界的热切关注。     

Assessment and applications of wind energy in Jordan

A technical and economic assessment has been made of the generation of electricity using windmills located at three most promising potential wind sites in Jordan: Ras Muneef (RA), Mafraq (MF), and Aqaba (AQ). The assessment was made for two different systems, one using a relatively large single windmill and the other using 25 small windmills arranged in a wind farm. The power output of each system at each site was determined, and the electricity-generating costs in each case were also determined and compared with the generating costs of generating electricity using steam or gas turbines, furnished by the Jordanian Electricity Authority (JEA).Finally, the possibility of water pumping from 30-m and 100-m deep wells using a windmill is investigated and the quantities of water pumping from these depths at each of the three sites are given.     

On the wind energy resources of Sudan

The imminent exhaustion of fossil energy resources and the increasing demand for energy were the motives for those reasonable in Sudan to put into practice an energy policy based on rational use of energy; and on exploitation of new, and renewable energy sources. After 1980, as the supply of conventional energy has not been able to follow the tremendous increase of the production demand in rural areas of Sudan, a renewed interest for the application of wind energy has shown in many places. Therefore, the Sudanese government began to pay more attention to wind energy utilisation in rural areas. Because the wind energy resource in many rural areas is sufficient for attractive application of wind pumps, and as fuel is insufficient, the wind pumps will be spread on a rather large scale in the near future. Wind is a form of renewable energy, which is always in a non-steady state due to the wide temporal and spatial variations of wind velocity. A number of years worth of data concerning wind speed in Sudan have been compiled, evaluated and presented in this article. The need for the provision of new data stations in order to enable a complete and reliable assessment of the overall wind power potential of the country is identified and specific locations suggested. This paper presents the background and ideas of the development of the concept as well as the main results, and experience gained during ongoing project up to now. In Sudan, various designs of wind machines for water pumping have been developed and some designs are presently manufactured commercially. Results suggest that wind power would be more profitably used for local-and small-scale applications especially for remote rural areas. It is concluded that Sudan is blessed with abundant wind energy.     

老爷庙风电场风能资源评价

本文利用老爷庙风电场2001年4月～2002年4月逐时平均风向、风速资料,对老爷庙风电场的风能资源各参数进行了计算和分析,并与附近星子气象站累年或同期资料进行比较,对老爷庙风电场风能资源进行评价。     

Assessment of wind energy potential in croatia

In this work, the eolian potential of Croatia (one of the Yugoslav republics) is investigated on the basis of 32 anemograph stations. Mean hourly values were used for calculation of Weibull's distribution parameter c and k, and mean annual and seasonal wind power densities. The vertical extrapolation of wind speeds was based on Justus expression. Mean annual wind energies were calculated for two types of aerogenerators. Analysis of these data showed that in the interior of Croatia, at 10 m above ground, low naturally available wind power densities exist: less than 50 W/m². On the Adriatic basin, in some area along the coast, a wind power of over 300 W/m² may be gained.

The annual natural wind energies at 50 m above ground lie in the continental part between 250 and 1300 kWh/m² and on the eastern part of Adriatic basin between 500 and 8100 kWh/m².     

西昌太阳能资源优

太阳辐射资源全国分为4个带区,即资源丰富带(6700兆焦/平方米·年);资源较丰富带(5400—6700兆焦/平方米·年);资源一般带(4200—5400兆焦/平方米·年);资源贫乏带(<4200兆焦/平方米·年),如四川盆地,贵州大部及云南西南部中缅边界一带等地,太阳能利用价值不大。西昌属资源较丰富带。从辐射水平看,不算最优,但结合气候特点和日照时间分布去认识,西昌太阳热水器年利用时间的优势就会凸显出来。西昌冬无严寒夏无酷暑,年均最高气温22.7℃,年均最低气温9.5℃,年均气温17.1℃。四季不分明,旱季(11～5月)和雨季(6～10月)十分明显。最冷月平均气温9…     

Assessment of wave energy resources in Hawaii

Hawaii is subject to direct approach of swells from distant storms as well as seas generated by trade winds passing through the islands. The archipelago creates a localized weather system that modifies the wave energy resources from the far field. We implement a nested computational grid along the major Hawaiian Islands in the global WaveWatch3 (WW3) model and utilize the Weather Research and Forecast (WRF) model to provide high-resolution mesoscale wind forcing over the Hawaii region. Two hindcast case studies representative of the year-round conditions provide a quantitative assessment of the regional wind and wave patterns as well as the wave energy resources along the Hawaiian Island chain. These events of approximately two weeks each have a range of wind speeds, ground swells, and wind waves for validation of the model system with satellite and buoy measurements. The results demonstrate the wave energy potential in Hawaii waters. While the episodic swell events have enormous power reaching 60 kW/m, the wind waves, augmented by the local weather, provide a consistent energy resource of 15–25 kW/m throughout the year.     

我国的风能资源在哪儿

地球上近地层每年的风能总量约为1.3×1015瓦,可利用的风能量至少为1012瓦,约为地球上可利用水能总量的10倍。我国的年风能储量为1.6×1012瓦,其中10%是可以利用的。     

佳木斯风能资源形成分布探讨

风能资源是清洁的可再生能源,风能发电是新能源领域中技术最成熟、最具规模开发条件和商业化发展前景的发电方式之一,也是目前清洁能源中利用最方便、最快捷、最少投入的可再生能源之一。已经成为世界能源可持续发展战略的重要组成部分。因此本文从风的形成原因、影响风速大小的因素、佳木斯风能资源的分布状况和可建风电规模（发展目标）等方面予以阐述,为佳木斯的风电发展提供理论参考根据。     

新疆太阳能资源及区划

分析了新疆太阳能辐射年分布状况和月分布状况。通过月总辐射分布曲线、月直达辐射分布曲线、月散射辐射分布曲线,分析了不同地区、不同月份太阳能辐射分布状况。采用三级区划指标对新疆太阳能资源进行了区划。第一级区划采用太阳能资源年总量;第二级区划采用水平表面直达辐射量(Qb)与总辐射量(Q)的比值;第三级区划采用环境温度和日照时数大于6 h的天数。通过三级区划划分了太阳能资源带、区;分析了带、区季节分布特征、日照大6 h的天数和日照气温大于10℃的天数。全面了解和掌握新疆太阳能资源状况,可为本地区的太阳能利用提供可靠的资料。     

青海省太阳能资源的开发利用

在调查了解青海省光伏发电产业发展情况的基础上,深入分析了青海省光伏发电产业的发展现状和存在问题,并提出了光伏发电产业健康发展的对策与措施,从而有效地促进青海省太阳能资源优势的发挥.