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As one of the most efficient and advantageous sources of renewable energy, wind energy is being developed and utilized at an expansive scale. The increase in installed capacity and the trend toward high-power wind turbines highlight the impacts of common-mode voltage (CMV), because CMV induces high-frequency electromagnetic interference (EMI) noise and destructive bearing currents through paths consisting of parasitic and coupling parameters. This review briefly introduces how CMV causes damages to wind power generation system, and then introduces CMV suppression strategies, including hardware-based and software-based methods. Three typical hardware-based methods are reviewed, including enhancing the components or structure of the generator, adding common-mode filters to the electric circuits, and changing the power converter topologies. These methods can effectively reduce CMV but introduce challenges such as demanding routine maintenance, and hardware redesigns. Software-based methods reviewed are mainly the modified pulse width modulation (PWM) schemes for the both the conventional three-phase two-level converters and the multilevel or multiphase converters. They actively suppress the source of CMV and have good cost-effectiveness. For example, a modified carrier-based PWM method can reduce the CMV root mean square value by more than 90 %. Pros and cons of all the reviewed CMV suppression methods are presented, which helps the readers to identify the most suitable solutions for practical applications. In general, it is recommended to adopt electrically insulated bearings, hybrid filters, multilevel converters, modified carrier-based PWM methods to compose the best wind power generation system in terms of the CMV performance. • Illustrates how common-mode voltage causes electromagnetic interference and bearing current in wind power systems. • Hardware-based solutions include improving the generator, adding EMI filters, and changing the power converter topology. • Software-based methods for three-phase two-level converters and multilevel or multiphase converters are reviewed. • Discuss pros and cons of common-mode voltage suppression methods to choose the best solutions for specific applications. [ABSTRACT FROM AUTHOR]

Abstract A fully integrated renewable energy atlas is presented which provides the wind and solar photo-voltaic (PV) power generation potential as well as cooling demand for Pakistan at a temporal resolution of 1-hr and spatial resolution of 14 × 14 km 2 . The proposed atlas uses weather based modelling for calculating renewable power generation time-series and the power-demand modelling is performed using real hourly electrical-load demand, conventional power generation and power consumption data for the year 2016. It has been found that Pakistan has much higher potential for the wind power generation than solar (PV) power generation and very good potential for the concentrated solar power. Furthermore, the optimum wind/solar power mix suggests that 95% of wind power generation and 5% of solar (PV) power generation leads to the least amount of power-shortfall. It is envisioned that the integration of renewable energy with cooling sector can be instrumental in overcoming Pakistan's electrical power-crisis. The current power-shortfall of 38.36 TW h can be resolved by installing rated wind and solar (PV) power generation capacity of 10.4 GW and 882 MW, respectively. Highlights • A fast and flexible high-resolution renewable energy atlas for Pakistan is presented. • Power-losses between the current power generation and consumption are almost 8%. • Power-shortfall of 38.36 TW h can be resolved with optimum wind/solar power mix of 95/5. • Geographical wind, solar PV power potential and cooling demand timeseries are calculated. • The significance of using weather-based modelling in energy system is shown. [ABSTRACT FROM AUTHOR]

Demand for energy is constantly rising worldwide whereas most conventional sources of energy are depleting. Environmental issues such as excessive greenhouse gas emissions impose additional constraints on the energy industry across the globe. Therefore, raising the share of clean sources of energy in power generation is of paramount importance. Wind power has specifically attracted large-scale investments in recent years since wind power is inherently ample, widely distributed and comes with minimal environmental impact. Wind, and consequently wind generated power are stochastic in nature. Therefore, wind energy is generally used in combination with fuel-based power to maintain reliability. Obviously, designing a reliable and efficient network of several power generation sources requires capacity planning. In this paper, a probabilistic optimization model is proposed for this purpose. The stochastic model uses a combination of recourse and chance-constrained approaches to assign optimal capacities to several sources of power generation including wind. Demand and wind generated power are both assumed stochastic and possibility of energy storage, importation and exportation are also considered in the network. [ABSTRACT FROM AUTHOR]

Within the EU׳s attempt to establish “world leadership” on energy and climate policy, Renewable Energy is an important component, with legally binding Renewables targets for 2020 established under the 2009 Renewables directive. The directive obliges EU Member states to provide “National Renewable Energy Action Plans”, setting out a detailed pathway to reaching their national-level Renewables targets under the directive. We compare actual progress in renewable electricity development against the intentions in the plans for the years 2011 and 2012, and we assess whether there are significant risks visible on failing to reach the targets. Five countries in the Nordic-Baltic region are studied: Sweden, Finland, Latvia, Lithuania and Estonia. These states have historical success in bioenergy and hydro development, but in general have limited experience in wind power and minimal use in solar power. We find that all five states are reaching their overall RES Electricity objective, but some countries are underperforming in newer RES technologies (e.g. wind), compensating for this by over-performing in more established technologies (e.g. biomass). This raises concern, since utilization of all available technologies will be needed to reach the 2020 targets. [ABSTRACT FROM AUTHOR]

Wind power generation has increased rapidly in China over the last decade. In this paper the authors present an extensive survey on the status and development of wind power generation in China. The wind resource distributions in China are presented and assessed, and the 10 GW-scale wind power generation bases are introduced in details. The domestic research status of main components of WP system is then elaborated, followed by an evaluation of the wind power equipment manufacturers. Finally, the outlook for the development of the wind power utilization in China is presented. [ABSTRACT FROM AUTHOR]

Geothermal, solar and wind are all clean, renewable energies with a huge amount of resources and a great potential of electricity generation. Geothermal energy had definitely dominated the renewable energy market in terms of the installed electricity power about 30 years ago. The unfortunate fact is that the total installed capacity of geothermal electricity has been eclipsed by solar and wind in recent years. In this paper, benefits of using renewable energy resources (RER) have been summarized and attempt has been made to explain the recent trends causing the shift from geothermal energy to solar and wind. Cost, payback time, size of power generation, construction time, resource capacity, characteristics of resource, and other factors were to compare geothermal, solar, and wind power generation systems. Furthermore, historical data from geothermal, solar, and wind industries were collected and analyzed at the global scale. The data from hydropower were also considered in the comparison. Finally, we proposed suggestions for the geothermal industry to catch up with solar and wind industries. [ABSTRACT FROM AUTHOR]

This paper presents analysis of the wind speed characteristics at Chuping and Kangar in Perlis, Malaysia. The characteristics consist of daily, monthly and annual mean wind speed. The Weibull distribution function is applied to analyze the wind speed characteristics and used to calculate the wind power generation potential. The wind power and energy as functions of tower height are presented and analyzed in this paper. The result shows that during 2005-2009 the mean wind speed at Chuping is 1.12m/s, and during 2012-2013 the mean wind speed at Kangar is 2.50m/s. Based on the analysis of the Weibull distribution function, the wind speed and probability density are, respectively, 0.97m/s and 73% at Chuping, also 2.5m/s and 45% at Kangar. They are important information to choose a suitable wind turbine for a wind power generation. The monthly mean wind power and energy density in the beginning (January-March) and the end (December) of year are higher than in the middle of year. The analysis result of the wind power and energy density as functions of tower height shows that higher tower height will produce higher wind power and energy density. [ABSTRACT FROM AUTHOR]

Abstract: Wind data analysis for the Sultanate of Oman is carried out in this study. The results are presented mainly in the form of contour maps, in addition to tabulated data and figures for average wind speed and direction as well as wind availability and power density spanning a period of ten years. The analysis covers diurnal, seasonal and height variations on wind parameters. The data used in the analysis were obtained from NASA Langley Research Center. This analysis provides a needed reference for the spatial distribution of wind characteristics for the whole of Oman from which possible locations for the deployment of wind-based energy conversion systems may be identified. [Copyright &y& Elsevier]

Abstract: In the world, wind power is rapidly becoming a generation technology of significance. Unpredictability and variability of wind power generation is one of the fundamental difficulties faced by power system operators. Good forecasting tools are urgent needed under the relevant issues associated with the integration of wind energy into the power system. This paper gives a bibliographical survey on the general background of research and developments in the fields of wind speed and wind power forecasting. Based on the assessment of wind power forecasting models, further direction for additional research and application is proposed. [Copyright &y& Elsevier]

Grid frequency support is one of the most challenging issues in wind rich islanded power systems. This problem becomes critical with the displacement of synchronous generators and their associated services (i.e., inertia and primary operating reserve). The services that are lost can be replaced by other sources, such as demand response schemes to enhance the resiliency and security of power system operations. Demand response based on internet data centers is expected to become an increasingly important asset to make a significant contribution to frequency ancillary services. To exploit this resource, internet service companies are expected to combine the capabilities of a variety of data centers to participate as a single provider similar to a virtual power plant. In this context, this work develops a novel framework for cooperative participation of data centers delay-tolerant workloads and backup power supply units to provide effective fast frequency response service. This is achieved by employing the model predictive controller to initiate reference signals to data center resources while respecting device operating conditions and constraints. Various case studies are run on the modified linear model of the 39 Bus system via dynamic simulations for the projected 75 % system non-synchronous penetration. Simulation results demonstrate the potential of different data center configurations to stabilize grid frequency during signal delays and severe cascade failures. The analysis shows that the proposed framework is critical to the adoption of renewable energy and reduces the requirement for an expensive spinning reserve used in a typical power system. • Data centers are power-intensive digital storage warehouses. • Data centers utilize array of redundant UPS systems could be deployed to provide grid supports. • Cloud of modern era can dynamically adjust their power consumption. • Storage in data centers can be used to provide fast frequency response ancillary services. • A novel framework for data centers to bid into electricity market and follow regulation signal in real-time. [ABSTRACT FROM AUTHOR]

Wind energy has been widely explored in recent decades and the integration of this renewable resource is increasing due to many factors, e.g., the need to mitigate climate change and reduce energy dependence on fossil fuels. Unfortunately, the stochastic characteristic of wind may have an impact on the reliability and power quality of electrical grids due to short-term power fluctuations. For wind power smoothing purposes, many researchers have been using energy storage systems (ESSs) as they perform extremely well, and are becoming less costly. In this context, this article presents a comprehensive review of the significant research conducted on the topic of wind power smoothing using high-power ESSs. Firstly, some energy storage technologies are discussed and compared, and a brief description of the main short-term applications of these technologies is provided. Afterwards, a literature review on wind power smoothing is conducted, showing evidence of the development of methods over the years. A bibliometric analysis is also presented, showing an increasing number of publications on this subject. Finally, this review indicates that more research is still needed to overcome wind power fluctuation issues and that further attention to topics such as hybrid ESSs and smoothing impacts on electrical grids should arise over the next years. • Short-term applications using energy storage systems. • A comprehensive review of the research conducted on wind power smoothing. • A bibliometric analysis concerning wind power smoothing. • Trends for future investigations on wind power smoothing. [ABSTRACT FROM AUTHOR]

China is the largest power producer and consumer and has the largest installed capacity of wind turbines (WTs) worldwide. In the last two decades, China's installed capacity of WTs has exploded, significantly impacting its wind power (WP) industry and promoting the development of the industry globally. This paper examines China as one part of the world and elucidates its role, status, and impact on global WP development from a global perspective. Research indicates that China has become the global leader in WP, its WP development has greatly promoted the growth rate of global WP, and it has become an indispensable force in global WP development. However, the comprehensive capability of China's WP generation is not only lower than that of other major WP countries but also lower than the global average. China's WTs have low global recognition and are difficult to export. In addition, the proportion of WP in China's power structure is lower than that of most other major WP countries. Fortunately, these gaps between China and other major WP countries are gradually narrowing. The goal of this paper is to help researchers and investors better understand China's situation and to provide a reference for the rational investment in and development of China's WP. • China has become a global wind power leader, but only in the installed capacity. • China's wind turbines have low recognition in global, and difficult to export. • Comprehensive capability of China's wind power is lower than that of global average. • Currently, China's wind power mainly wins in terms of quantity rather than quality. [ABSTRACT FROM AUTHOR]