Synergies of scale: A vision of Mongolia and China's common energy future

Energy consumption in China is expected to double over the next 20 years. Addressing the enormous scale of China's energy need and attendant increases in greenhouse gas emissions requires dramatic and rapid rollout of renewable energy technologies. Mongolia has some of the world's best renewable energy resources but the scale of its market cannot tap them efficiently. Developing Mongolia into a significant exporter of renewable energy to China will create synergies of scale moving both countries towards their energy goals, creating jobs, and fostering growth while significantly reducing GHG emissions in the region.     

Demand side resource operation on the Irish power system with high wind power penetration

The utilisation of demand side resources is set to increase over the coming years with the advent of advanced metering infrastructure, home area networks and the promotion of increased energy efficiency. Demand side resources are proposed as an energy resource that, through aggregation, can form part of the power system plant mix and contribute to the flexible operation of a power system. A model for demand side resources is proposed here that captures its key characteristics for commitment and dispatch calculations. The model is tested on the all island Irish power system, and the operation of the model is simulated over one year in both a stochastic and deterministic mode, to illustrate the impact of wind and load uncertainty. The results illustrate that demand side resources can contribute to the efficient, flexible operation of systems with high penetrations of wind by replacing some of the functions of conventional peaking plant. Demand side resources are also shown to be capable of improving the reliability of the system, with reserve capability identified as a key requirement in this respect.     

An investigation on the impacts of regulatory interventions on wind power expansion in generation planning

Large integration of intermittent wind generation in power system has necessitated the inclusion of more innovative and sophisticated approaches in power system investment planning. This paper presents a novel framework on the basis of a combination of stochastic dynamic programming (SDP) algorithm and game theory to study the impacts of different regulatory interventions to promote wind power investment in generation expansion planning. In this study, regulatory policies include Feed-in-Tariff (FIT) incentive, quota and tradable green certificate. The intermittent nature and uncertainties of wind power generation will cause the investors encounter risk in their investment decisions. To overcome this problem, a novel model has been derived to study the regulatory impacts on wind generation expansion planning. In our approach, the probabilistic nature of wind generation is modeled. The model can calculate optimal investment strategies, in which the wind power uncertainty is included. This framework is implemented on a test system to illustrate the working of the proposed approach. The result shows that FITs are the most effective policy to encourage the rapid and sustained deployment of wind power. FITs can significantly reduce the risks of investing in renewable energy technologies and thus create conditions conducive to rapid market growth.     

Parametric dependence of a morphing wind turbine blade on material elasticity

A few recent works have suggested a morphing blade for wind turbine energy conversion. The concept is derived from fin and wing motions that better adapt to varying load conditions. Previous research has provided the fluid mechanic justification of this new concept. This paper establishes a parametric relationship between an asymmetric wind turbine blade and constituent material modulus to predict the geometric response of the morphing blade for a given material characteristic. The airfoil’s trailing edge deflection is associated to a prescribed fluid exit angle via the Moment Area (MA) method. Subsequently, a mathematical model is derived to predict material deformation with respect to imparted aerodynamic forces. Results show that an airfoil, much like a tapered beam, can be modeled as a non-prismatic cantilevered beam using this well established method.     

Assessment of wind energy potentiality at Kudat and Labuan, Malaysia using Weibull distribution function

The wind resource is a crucial step in planning a wind energy project and detailed knowledge of the wind characteristic at a site is needed to estimate the performance of a wind energy project. In this paper, with the help of 2-parameter Weibull distribution, the assessment of wind energy potentiality at Kudat and Labuan in 2006-2008 was carried out. “WRPLOT” software has been used to show the wind direction and resultant of the wind speed direction. The monthly and yearly highest mean wind speeds were 4.76 m/s at Kudat and 3.39 m/s at Labuan respectively. The annual highest values of the Weibull shape parameter (k) and scale parameter (c) were 1.86 and 3.81 m/s respectively. The maximum wind power density was found to be 67.40 W/m² at Kudat for the year 2008. The maximum wind energy density was found to be 590.40 kWh/m²/year at Kudat in 2008. The highest most probable wind speed and wind speed carrying maximum energy were estimated 2.44 m/s at Labuan in 2007 and 6.02 m/s at Kudat in 2007. The maximum deviation, at wind speed more than 2 m/s, between observed and Weibull frequency distribution was about 5%. The most probable wind directions (blowing from) were 190° and 269° at Kudat and Labuan through the study years. From this study, it is concluded that these sites are unsuitable for the large-scale wind energy generation. However, small-scale wind energy can be generated at the turbine height of 100 m.     

Effect of the angle of attack on the wind convection coefficient

In this study the effect of the positive angle of attack (angle between flat plate surface and incoming uniform flow) on the convective heat transfer coefficient was investigated numerically. In the case of inviscid flow, this effect was also presented analytically and was found to be in good agreement with the corresponding numerical results. From the obtained numerical data, an accurate correlation equation of Nusselt number was proposed by introducing the effect of the angle of attack in terms of a new factor A_f. The variation of the convective heat transfer coefficient as a function of the angle of attack was found not behaves in the same manner for both small and large values of Prandtl number at small angles of attack.     

西班牙风电发展及对我国的启示——西班牙歌美飒公司专访

随着我国风电装机规模的不断扩大,对风电接入电网及风电设备的安全运行管理提出了新的更高要求。笔者通过亲赴西班牙实地考察,了解了西班牙风电的发展状况和趋势。本文通过在西班牙考察的所见所闻,总结了西班牙风电发展的成功经验,并对我国风电的健康持续发展提出了相关建议。     

离心风机噪声控制研究

在通风设备中,尽管经常使用离心风机,但是它在运转过程中产生的强噪声,令人心烦,危险极大。本文主要从如何改进风机本身结构参数,而不是采用一种消声器来降低风机噪声的角度进行探讨。     

开敞式钢框架风荷载计算中的不确定性及对策

开敞式钢框架不同于民用多高层建筑,没有维护墙,整个结构骨架、平台、栏杆梯子和设备等全都暴露在风的作用下。设备等质量源在空间上分布不均匀性及平台或梁错层等因素使结构动力特性更复杂。因此。该类结构静力和动力风荷载计算存在诸多不确定性。     

Simulation model for wind turbine with asynchronous generator interconnected to the electric network

This paper presents the study of a structure composed of a wind turbine, a speed multiplier and an asynchronous generator coupled to the infinite power network through a line of energy transfer electric modelled by an R–L circuit. After modelling of the global system, the behaviour of the proposed structure in steady states and in transient regimes is studied. The problem of the electric energy transfer to the network was studied. On the other hand, if the wind speed changes too much variation, this will cause a violent variation of power and result in step out operation of the generator from the power system. This paper proposes a control strategy to reduce the power variations by introducing feed forward control combined with conventional feedback control.