Evaluation of wind energy potential as a power generation source for electricity production in Binalood,Iran

In this paper, the hourly measured wind speed data for years 2007–2010 at 10 m, 30 m and 40 m height for Binalood region in Iran have been statically analyzed to determine the potential of wind power generation. The study showed that the long-term wind speeds were found to be relatively high. The numerical values of the dimensionless Weibull shape parameter (k) and Weibull scale parameters (c) were also determined. Based on these data, it was found that the numerical values of the shape and scale parameters for Binalood varied over a wide range. The yearly values of k at 40 m elevation range from 2.165 to 2.211 with a mean value of 2.186, while those of c are in the range of 7.683–8.016 with a mean value of 7.834. However, the yearly mean wind speed, mean power density and power density of Binalood at 40 m height are found as 5.923 m/s, 305.514 W/m² and 2676.30 (kWh/m²/year) respectively. The results show that Binalood has available great wind energy potential for grid connection system.     

Evaluation of distributed building thermal energy storage in conjunction with wind and solar electric power generation

Energy storage is often seen as necessary for the electric utility systems with large amounts of solar or wind power generation to compensate for the inability to schedule these facilities to match power demand. This study looks at the potential to use building thermal energy storage as a load shifting technology rather than traditional electric energy storage. Analyses are conducted using hourly electric load, temperature, wind speed, and solar radiation data for a 5-state central U.S. region in conjunction with simple computer simulations and economic models to evaluate the economic benefit of distributed building thermal energy storage (TES). The value of the TES is investigated as wind and solar power generation penetration increases. In addition, building side and smart grid enabled utility side storage management strategies are explored and compared. For a relative point of comparison, batteries are simulated and compared to TES. It is found that cooling TES value remains approximately constant as wind penetration increases, but generally decreases with increasing solar penetration. It is also clearly shown that the storage management strategy is vitally important to the economic value of TES; utility side operating methods perform with at least 75% greater value as compared to building side management strategies. In addition, TES compares fairly well against batteries, obtaining nearly 90% of the battery value in the base case; this result is significant considering TES can only impact building thermal loads, whereas batteries can impact any electrical load. Surprisingly, the value of energy storage does not increase substantially with increased wind and solar penetration and in some cases it decreases. This result is true for both TES and batteries and suggests that the tie between load shifting energy storage and renewable electric power generation may not be nearly as strong as typically thought.     

Performance study of power density in PEMFC for power generation from solar energy

A study has been carried-out on power density in the Proton Exchange Membrane Fuel Cell (PEMFC) for its application for solar power generation. It involves a fuel cell approach assisted with specific electro-catalysts to process special chemical coupling (2-propanol/acetone/H₂) for generating the power. This knowledge will be useful for designing the solar power generation system based on this special chemical coupling enabling to use low-grade solar heat (<100 °C). For this purpose, a wide study has been conducted in the PEMFC using different catalytic electrodes at various orientations (0°, 45° and 90°). The investigations were carried-out at different temperatures from 45 °C to 60 °C using liquid oxidant mixtures in different proportions. The maximum power density attained was 1.78 mW cm^?2 at 60 °C. The PEMFC based technique for solar power generation may prove to be a promising option to harness this everlasting source of sun’s energy in the coming future.     

Technoeconomic analysis of electricity generation from wind energy in Kutahya,Turkey

Conventional energy usage has various environmental effects that cause global warming. Renewable energy sources are thus more favorable because they have nearly zero emission. Wind energy, among the various renewable sources, finds increasing usage, concurrent with developing technology. In addition, wind is an infinite energy source. In this study, the electricity-generation ability of Kutahya has been investigated. With this aim, wind data, from the measurement station located on Bunelek Hill, Kutahya, have been collected for a period of 36 months (July 2001–June 2004). From the collected data, the electricity generated has been calculated for different types of wind turbines. The calculations have been based on the electricity requirement of the main campus of the Dumlupinar University. Finally, the economic evaluation has been analyzed using life-cycle cost analysis. For the analysis of the economical aspects, the social and CO₂ costs have also been taken into account.     

A probabilistic method for the evaluation of the reliability ofstand alone wind energy systems

The author describes a probabilistic method for the computation of the loss of load probability and the expected unserved energy of a stand-alone wind energy system. The system consists of a wind generator and a storage battery supplying the consumer load. The statistics of the surplus generation (excess wind generation over load demand) time series are computed and used for the calculation of the desired reliability indices. It is shown, that in the probability computations, the serial correlation of the surplus generation cannot be ignored. The performance of the developed method is demonstrated with computational results. Some results useful for the design of stand-alone wind energy systems are also presented     

The interaction of wind power generation with electricity demand in the context of a small grid

An investigation into the integration of the intermittent electricity output of a hypothetical wind farm in Malta with the actual electricity demand for one particular year is reported. Available hourly wind data from three sites for 2001 were analysed. The probability density of the load resulting from the reduction of the renewable output from the electricity demand on an hourly basis was determined by a convolution method. The calculated shift in the load duration extends over the whole spectrum of power demand. The equivalent power at the most favourable site was considerably higher than the nominal value commonly in use. In view of the limited availability of sites for wind farms in Malta rotor designs better suited to the lower wind speed régime inland should be considered.     

Calculation of economic transmission connection capacity for wind power generation

Applications for the connection of large-scale wind power generation to transmission networks are presenting new issues both for transmission system planners and generation developers. One of the major problems faced is the assessment of transmission system capacity requirements for the export of power from areas with high penetration of variable and intermittent sources of generation such as wind power. A method for evaluating the required transmission connection capacity from an area dominated by wind generation to the main interconnected system is presented, based on historical time series data for both wind power generation output and the demand in the group. The operational implications for the transmission system and generation owners are evaluated using a cost-benefit approach. The method is demonstrated for a number of network situations. Conclusions are drawn about the value of the method and, more generally, about the trade-off between investment in transmission capacity and curtailment of wind generation under favourable wind conditions     

Evaluation of wind energy investment interest and electricity generation cost analysis for Turkey

Turkey has remarkable wind energy potential, but its utilisation rate is very low. However, in 2007, energy investors applied to the Energy Market Regulatory Authority (EMRA) with 751 wind projects to obtain a 78180.2 MW wind power plant license. This paper first presents an overview of wind energy development in the world and then reviews related situations in Turkey. Second, to motivate the interest in wind energy investment, new wind power plant license applications in Turkey are analysed. Finally, wind electricity generation cost analyses were performed at 14 locations in Turkey. Capacity factors of investigated locations were calculated between 19.7% and 56.8%, and the production cost of electrical energy was between 1.73 and 4.99 $cent/kW h for two different wind shear coefficients.     

Performance of a direct steam generation solar thermal power plant for electricity production as a function of the solar multiple

This paper describes the influence of the solar multiple on the annual performance of parabolic trough solar thermal power plants with direct steam generation (DSG). The reference system selected is a 50 MW_e DSG power plant, with thermal storage and auxiliary natural gas-fired boiler. It is considered that both systems are necessary for an optimum coupling to the electricity grid. Although thermal storage is an opening issue for DSG technology, it gives an additional degree of freedom for plant performance optimization. Fossil hybridization is also a key element if a reliable electricity production must be guaranteed for a defined time span. Once the yearly parameters of the solar power plant are calculated, the economic analysis is performed, assessing the effect of the solar multiple in the levelized cost of electricity, as well as in the annual natural gas consumption.     

Analysis of systems for the generation of electricity from solar radiation

The analysis developed here relates the annual electrical output of any type of solar-electric facility directly to the effective annual insolation received on its solar collectors per unit collector area. A general expression for the capacity factor of such a facility is derived through which the ratio of the actual annual electrical output to the maximum mean annual output without demand, generating and downtime reductions, and storage losses can be determined. A general expression for a solar availability factor is also obtained which measures the ratio of the maximum mean annual output of the solar facility to that of a conventional fuel-fired plant of the same installed capacity generating at full capacity continuously for a year. An expression for the fraction of the total electrical output supplied by the solar facility is also derived. The analysis takes full account of the daily and seasonal cycles of solar radiation and its intermittent stochastic character. All results are given for a unit area of solar collector and are thus independent of the size of the facility.The capital cost of solar-electric facilities is expressed in dollars for each kWh per yr of electrical output rather than dollars per kW of installed capacity as is customary for conventional electric generating plants. This cost in turn is divided among three components: for solar-electric generation, for nonsolar auxiliary power, and for storage. A general expression is derived in terms of actual or estimated component costs, and the results for solar generation and storage are shown in Figs. 4 and 5. The choice of solar collector area and of the relative dependence on storage and auxiliary nonsolar power is also discussed.     

用于风电功率平抑的飞轮储能阵列功率协调控制策略

风电输出功率存在随机性和波动性的问题,使得电网调频难度加大.采用飞轮储能匹配风电的形式可以减小其功率波动,提高并网能力.以交流母线并联的飞轮储能阵列为研究对象,首先针对现有功率分配策略中存在的问题,提出一种考虑功率分配上限和能使各单元荷电状态(SOC)趋于一致的功率协调控制策略.同时为保证功率控制精度和储能系统的响应速...     

A new probabilistic method to estimate the long-term wind speed characteristics at a potential wind energy conversion site

This paper proposes the use of a new Measure-Correlate-Predict (MCP) method to estimate the long-term wind speed characteristics at a potential wind energy conversion site. The proposed method uses the probability density function of the wind speed at a candidate site conditioned to the wind speed at a reference site. Contingency-type bivariate distributions with specified marginal distributions are used for this purpose. The proposed model was applied in this paper to wind speeds recorded at six weather stations located in the Canary Islands (Spain). The conclusion reached is that the method presented in this paper, in the majority of cases, provides better results than those obtained with other MCP methods used for purposes of comparison. The metrics employed in the analysis were the coefficient of determination (R²) and the root relative squared error (RRSE). The characteristics that were analysed were the capacity of the model to estimate the long-term wind speed probability distribution function, the long-term wind power density probability distribution function and the long-term wind turbine power output probability distribution function at the candidate site.     

Analysis of output power smoothing method of the solar chimney power generating system

Severe fluctuation of the output power is a common problem in the generating systems of various renewable energies. The concept of output power fluctuation factor of renewable energy power generating systems was put forward in this paper. Aiming to decrease the fluctuation factor of output power in solar chimney power generating systems (SC), a novel hybrid energy storage system made of water, and sandstone was employed to replace the traditional sandstone energy storage system. The mathematical models of fluid flow, heat transfer and power generating features of SC were established and the influences of material, depth, areas and location of the energy storage layer upon output power were analyzed. The simulation results indicated that adopting the hybrid energy storage of water and sandstone can effectively decrease the fluctuation factor of SC output power and hence smooth the SC output power. In addition, according to the largest daily power generating capability or the smallest peak fluctuation factor, the corresponding optimum depth of the water energy storage layer would be 5 cm or 20 cm, respectively. Copyright © 2012 John Wiley & Sons, Ltd.     

Potential application of concentrating solar power systems for the generation of electricity in Thailand

This study aims to investigate a potential application of concentrating solar power (CSP) systems for producing electricity in the tropical environment of Thailand. An 8-year period (1995–2002) of satellite data was used to generate the direct normal irradiation map of the country. The map reveals that the areas which receive the highest irradiation are mainly in the Northeast and the Central regions of the country, with the yearly sum of direct normal irradiation in the range of 1350–1400 kW h/m² year. The location of Ubon Ratchathani (15.25 °N, 104.87 °E) situated in the Northeast was selected as a target area for investigating the potential application of CSP systems. The performance of three 10 MW CSP systems, namely the parabolic trough, the tower and the dish/Stirling engine systems was investigated. A software named TRNSYS together with the solar thermal electric components (STEC) subroutines were used to simulate the systems. The yearly production of electricity from these systems was estimated and used for the economic evaluation of the systems. It was found that the parabolic trough system afforded the lowest levelized electricity cost of 0.30 USD/kW h. Based on the technical and economic considerations, this system has a sufficient potential for producing electricity in this region.     

Trading wind energy on the basis of probabilistic forecasts both of wind generation and of market quantities

Wind power is not easily predictable and non‐dispatchable. Nevertheless, wind power producers are increasingly urged to participate in electricity market auctions in the same manner as conventional power producers. The aim of this paper is to propose an operational strategy for trading wind energy in liberalized electricity markets and to assess its performance. At first, the so‐called optimal quantile strategy is revisited. It is proved that without market power, i.e. under the price‐taker assumption, this strategy maximizes expected market revenues. Forecasts of wind power production, of day‐ahead and real‐time market prices and of the system imbalance are inputs to this strategy. Subsequently, constraining of the bid that maximizes the expected revenues is proposed as a way to overcome the strategy's disregard of practical limitations and, at the same time, of risk. Two constraining techniques are introduced: constraining in the decision space and in the probability space. Finally, the trade of a wind power producer is simulated in a test case for the Eastern Danish (DK‐2) price area of the Nordic Power Exchange (Nord Pool) during a 10 month period in 2008. The results of the test case show the financial benefits of the aforementioned strategy as well as the consequent interaction with the electricity market. This study will support a demonstration in the framework of the EU project ANEMOS.plus. Copyright © 2012 John Wiley & Sons, Ltd.     

基于双电池不平衡状态优化的风功率平滑控制

在双电池平滑风功率过程中,改善双电池充放电不平衡状态可以提高充放电深度,减少充放电状态切换次数.文章分析了双电池风功率平滑系统的充放电不平衡状态及其产生的原因,提出了一种改进控制策略,该策略可根据双电池荷电状态调整风功率平抑目标功率,以此改善双电池不平衡状态.基于Matlab/Simulink分析了风速湍流强度以及风功...     

Electric energy generation from small-scale solar and wind power in Brazil: The influence of location,area and shape

Power production from renewable sources is identified as one of the tools to attain sustainable development in economic and social terms in Brazil. Awareness of how to prioritize renewable energy sources and technologies becomes increasingly important. Solar and wind energy have been highlighted in this context as being clean, safe and also relatively mature technologies. In addition, they are also renowned for having great energy potential and allowing different mounting options for energy harvesting systems. This article seeks to contribute to the knowledge of the effects that the key attributes, location, area and shape, of a site can have on the potential of renewable generation. In order to incorporate these attributes into an integrated analysis, a comparison method is developed and subsequently applied in a case study for two Brazilian cities. Results indicate that the amount of energy obtained by a given power generation system can undergo large variations depending on the characteristics of attributes such as site location, area and shape. This variation may ultra-pass 200%, in some cases, which demonstrates the importance of a better understanding of the role of these attributes in determining energy production.     

Statistical voltage quality assessment method for grids with wind power generation

The impact of wind generators on voltage control of the network has been analysed via a statistical approach. A probabilistic model was developed by taking into consideration the stochastic nature of the wind and the availability status of the network elements. The proposed statistical method estimates the voltage deviation at the point of common coupling and its probability of occurrence. An index, termed significant level of voltage deviation, has also been proposed to aid in evaluating strategies for mitigating voltage quality problems. Numerical case study is presented to illustrate the proposed method and to compare its performance against other methods.     

Conceptualizing the acceptance of wind and solar electricity

Drawing from research interviews and the academic literature, this article conceptualizes the conditions that promote investor confidence and the social acceptance of wind and solar sources of electricity. It explores the factors influencing the acceptance of commercial wind turbines in Denmark and India and residential solar panels in Germany and the United States. The article begins by justifying its selection of case studies and explaining the methodology behind its research interviews and field visits. It then summarizes some of the key findings in recent surveys of public attitudes and market acceptance concerning renewable energy, with a focus on why some investors and communities reject wind and solar systems whereas others rapidly approve and adopt them. The article proposes that acceptance has multiple dimensions – socio-political, community, and market – that must be met holistically in order for investors and users to embrace renewable energy. The article argues that acceptance hinges upon the prevalence of nine factors; the lack of such factors creates environments where they are rejected. The theory is tested against four case studies that explore the forces driving renewable energy in Denmark, Germany, India, and the United States.