Evaluation of hydrogen production by wind energy for agricultural and industrial sectors

Wind power potential by itself is not a good indicator of the suitability of a region for wind power generation for different purposes. Economic attractiveness is a better indicator in this regard as it stimulates the involvement of private businesses in this sector. Naturally, the shorter is the payback period or the time required to reach profitability, the more attractive will be the project. Considering the high wind energy potential of some regions of Iran, this study evaluates the wind energy available for generating electricity as well as hydrogen by industrial and agricultural sectors in four cities of Ardebil province, namely Ardebil, Khalkhal, Namin, and Meshkinshahr, and then conducts an econometric analysis accordingly. Wind power potentials are evaluated using the energy pattern factor and Weibull distribution function based on 5-year meteorological data of the studied regions. Economic evaluations are performed based on the present worth of incomes and costs, which are estimated for two models of wind turbines with 3.5 and 100 KW rated power. Results indicate that the cities of Namin and Ardebil with wind power densities of respectively 261.68 and 258.99 W/m² have the best condition. The economic analysis conducted for turbines shows that for Ardebil, installation of the 3.5 KW and 100 KW turbines will have a payback period of 13 and 5 years, respectively. For Khalkhal, Namin, and Meshkinshahr, the only feasible option is installation of the 100 KW turbine, which would result in a payback period of respectively 10.2, 6.1 and 8.7 years. Then it is investigated how much hydrogen can be gained if these private sectors invest in producing hydrogen using nominated wind turbines.     

Assessment of wind energy in Iran: A review

In this study, a ten minute period measuring wind speed data for year 2007 at 10 m, 30 m and 40 m heights for different places in Iran, has been statistically analyzed to determine the potential of wind power generation. Sixty eight sites have been studied. The objective is to evaluate the most important characteristics of wind energy in the studied sites. The statistical attitudes permit us to estimate the mean wind speed, the wind speed distribution function, the mean wind power density and the wind rose in the site at three different heights. Some local phenomena are also considered in the characterization of the site.     

A new semi-empirical wind turbine capacity factor for maximizing annual electricity and hydrogen production

The capacity factor is an important wind turbine parameter which is ratio of average output electrical power to rated electrical power of the wind turbine. Another main factor, the AEP, the annual energy production, can be determined using wind characteristics and wind turbine performance. Lower rated power may lead to higher capacity factor but will reduce the AEP. Therefore, it is important to consider simultaneously both the capacity factor and the AEP in design or selecting a wind turbine. In this work, a new semi-empirical secondary capacity factor is introduced for determining a rated wind speed at which yearly energy and hydrogen production obtain a maximum value. This capacity factor is expressed as ratio of the AEP for wind turbine to yearly wind energy delivered by mean wind speed at the rotor swept area. The methodology is demonstrated using the empirical efficiency curve of Vestas-80 2 MW turbine and the Weibull probability density function. Simultaneous use of the primary and the secondary capacity factors are discussed for maximizing electrical energy and hence hydrogen production for different wind classes and economic feasibility are scrutinized in several wind stations in Kuwait.     

Evaluation of wind energy potential and electricity generation at six locations in Turkey

In this study, wind characteristics were analyzed using the wind speed data collected of the six meteorological stations in Turkey during the period 2000–2006. The annual mean wind speed of the six stations (Erzurum, Elaz??, Bingöl, Kars, Manisa and Ni?de) is obtained as 8.7, 8.5, 5.9, 6.9, 7.4 and 8.0 m/s at 10 m height, respectively. The mean annual value of Weibull shape parameter k is between 1.71 and 1.96 while the annual value of scale parameter c is between 6.81 and 9.71 m/s. A technical assessment has been made of electricity generation from four wind turbines having capacity of (600 kW, 1000 kW, 1500 kW and 2000 kW). The yearly energy output and capacity factor for the four different turbines were calculated.     

Analysis of two-component mixture Weibull statistics for estimation of wind speed distributions

The typical two-parameter Weibull is a flexible distribution that is useful for describing unimodal frequency distributions of wind speeds at many sites. A two-component mixture Weibull distribution (WW-probability distribution function (pdf)) is even more useful because it is additionally able to represent heterogenous wind regimes in which there is evidence of bimodality or bitangentiality or, simply, unimodality.An analysis is made in this paper of three of the most frequently used methods in the estimation of the five parameters of the WW-pdf and the numerical methods employed are described. Hourly mean wind speed data recorded at four weather stations located in the island of Gran Canaria (Spain) are used to analyse the estimation methods. Prior identification of the sample components of the mixture is not required.The suitability of the distributions is judged from the various tests-of-fit commonly used in the specialised literature on wind energy. A comparison is also made of the ability to describe the experimental wind power density distribution. The general conclusion is that if the sample data are independent then maximum likelihood (ML) estimators should be used due to their large sampling efficiency. However, they require elaborate calculation techniques. The least-square (LS) method provides a robust and computationally efficient alternative to the techniques currently in use. The method of moments has the disadvantage that it does not always supply a feasible result and lacks the desirable optimality properties of ML and LS estimators.     

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.     

Comparison of seven numerical methods for determining Weibull parameters for wind energy generation in the northeast region of Brazil

This paper deals with the analysis and comparison of 7 (seven) numerical methods for the assessment of effectiveness in determining the parameters for the Weibull distribution, using wind speed data collected in Camocim and Paracuru cities, State of Ceará, in the northeast region of Brazil, in the period from August 2004 to April 2006, obtained by the Department of Infrastructure of the State of Ceará. One method is not well known, namely the equivalent energy method, and its performance is compared to the others. By using the methods of analysis of variance, RMSE (root mean square error), and chi-square tests to compare the proposed methods, this study aims to determine which ones are effective in determining the parameters of the Weibull distribution for the available data, in an attempt to establish acceptable criteria to a better utilization of wind power in the State of Ceará, which is a national prominence in the use of renewable sources for electricity generation in Brazil.     

Feasibility study of wind energy potential in two provinces of Iran: North and South Khorasan

In this study, the measured wind speed data for year 2007 at 10 m, 30 m and 40 m heights for two provinces of Iran, North and South Khorasan, have been statistically analyzed to determine the potential of wind power generation. This paper presents the wind energy potential at four zones in these provinces, Bojnourd, Esfarayen of North Khorasan province and Nehbandan, and Fadashk of South Khorasan province. The objective is to evaluate the most important characteristic of wind energy in the studied sites. The statistical attitudes permit us to estimate the mean wind speed, the wind speed distribution function, the mean wind power density in the sites at the height of 10 m, 30 m and 40 m. Also, three new types of wind rose diagrams were shown.     

Validity analysis of maximum entropy distribution based on different moment constraints for wind energy assessment

Knowing about wind speed distribution for a specific site is very essential step in wind resource utilizations. In this paper, a probability density function with the maximum entropy principle is derived using different algorithm from previous studies. Its validity considering various numbers of moment constraints is tested and compared with the conventional Weibull function in terms of computation accuracy. Judgment criterions include the Chi-square error, root mean square error, maximum error in cumulative distribution function as well as the relative error of wind power density between theoretical function and observation data. Wind sample data are observed at four wind farms having different weather conditions in Taiwan. The results show that the entropy quantities reveal a negative correlation with the number of constraints used, regardless of station considered. For a specific site experiencing more stable weather condition where wind regimes are not too dispersive, the conventional Weibull function may accurately describe the distribution. While for wind regimes having two humps on it, the maximum entropy distributions proposed outperform a lot the Weibull function, irrespective of wind speed or power density analyzed. For the consideration of computation burden, using four moment constraints in calculating maximum entropy parameters is recommended in wind analysis.     

Economic viability and production capacity of wind generated renewable hydrogen

Generally, wind to power conversion is calculated by assuming the quality of wind as measured with a Weibull probability distribution at wind speed during power generation. We build on this method by modifying the Weibull distributions to reflect the actual range of wind speeds and wind energy density. This was combined with log law that modifies wind speed based on the height from the ground, to derive the wind power potential at windy sites. The study also provides the Levelized cost of renewable energy and hydrogen conversion capacity at the proposed sites. We have also electrolyzed the wind-generated electricity to measure the production capacity of renewable hydrogen. We found that all the sites considered are commercially viable for hydrogen production from wind-generated electricity. Wind generated electricity cost varies from $0.0844 to $0.0864 kW h, and the supply cost of renewable hydrogen is $5.30 to $ 5.80/kg-H₂. Based on the findings, we propose a policy on renewable hydrogen fueled vehicles so that the consumption of fossil fuels could be reduced. This paper shall serve as a complete feasibility study on renewable hydrogen production and utilization.     

Wind characteristics and wind energy potential in Morocco

The wind characteristics of 11 sites in the windy regions in Morocco have been analysed. The annual average wind speed for the considered sites ranged from 5 m/s to 10 m/s and the average power density from 100 W/m² to 1000 W/m², which might be suitable for electrical power production by installing wind farms. On an annual scale the observations of the distribution of hourly wind speed are better fitted by the Weibull hybrid distribution in contrast to the Weibull distribution.The wind power is estimated to be 1817 MW, that is to say, the exploitable wind energy is 15198 GWh, which represents theoretically 11% of the total consumed energy in Morocco in 1994.     

An economic analysis of the production of hydrogen from wind-generated electricity for use in transport applications

Wind-generated electricity is often considered a particularly promising option for producing hydrogen from renewable energy sources. However, the economic performances of such systems generally remain unclear because of unspecified or favorable assumptions and operating conditions. The aim of this paper is to clarify these conditions by examining how the hydrogen produced is used. The analysis that has been conducted in the framework of the HyFrance 3 project concerns hydrogen for transport applications. Different technical systems are considered such as motorway hydrogen filling stations, Hythane®-fueled buses or second-generation biofuels production, which present contrasted hydrogen use characteristics. This analysis reveals considerable variations in hydrogen production costs depending on the demand profiles concerned, with the most favorable configurations being those in which storage systems are kept to a minimum.     

Hydrogen production from idle generation capacity of wind turbines

This paper is concerned with the hydrogen production from wind energy. It is motivated by the new regulations for wind farms that compel them to operate normally with idle generation capacity. The idea is to use the excess wind power to produce hydrogen. The operation of a proposed system configuration, which essentially consists in incorporating an electrolyzer between the electronic converters of a conventional wind turbine, is analyzed. In particular, the control requirements to simultaneously achieve the grid and electrolyzer specifications are investigated. In this context, a control strategy for the different operating modes of the system is developed.     

Evaluation of a wind energy based system for co-generation of hydrogen and methanol production

A novel idea of wind energy based methanol and hydrogen production is proposed in this study. The proposed system utilizes the industrial carbon emissions to produce a useful output of methanol. There are several pros of manufacturing the methanol as it has the capability to be employed as conventional automotive fuel as it carries the advantages of efficient performance, low emissions and low flammability risk. The designed system comprises of the major subsystems of wind turbines, proton exchange membrane fuel cell (PEMFC), methanol production system and distillation unit. The Engineering Equation Solver (EES) and Aspen Plus are utilized for system modeling and comprehensive analysis. The proposed system is also investigated to operate under different wind speeds and different wind turbine efficiencies. The proposed integration covers all the electric power required by the system. The industrial flue gas including CO₂ reacts with hydrogen to produce methanol. The designed system produces both methanol and hydrogen simultaneously. For the performance indicator, efficiencies of the overall system are calculated. The exergetic efficiency is found to be 38.2% while energetic efficiency is determined to be 39.8%. Furthermore, some parametric studies are conducted to investigate the distillation column performance, methanol and hydrogen capacities and exergy destruction rates.     

Investigation of wind characteristics and wind energy potential in Kirklareli, Turkey

Utilization of wind energy as an energy source has been growing rapidly in the whole world due to environmental pollution, consumption of the limited fossil fuels and global warming. Although Turkey has fairly high wind energy potential, exploitation of the wind energy is still in the crawling level. In the current study, wind characteristics and wind energy potential of Kırklareli province in the Marmara Region, Turkey were analyzed taking into account the wind data measured as hourly time series. The wind data used in the study were taken from Electrical Power Resources Survey and Development Administration (EIEI) for the year 2004. The measured wind data were processed as annual, seasonal and monthly. Weibull and Rayleigh probability density functions of the location are calculated in the light of observed data and Weibull shape parameter k and scale parameter c are found as 1.75 and 5.25 m/s for the year 2004. According to the power calculations done for the site, annual mean power density based on Weibull function is 138.85 W/m². The results indicate that investigated site has fairly wind energy potential for the utilization.     

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.     

Analysis of hydrogen production from combined photovoltaics, wind energy and secondary hydroelectricity supply in Brazil

In this work, the technical and economical feasibility for implementing a hypothetical electrolytic hydrogen production plant, powered by electrical energy generated by alternative renewable power sources, wind and solar, and conventional hydroelectricity, was studied mainly trough the analysis of the wind and solar energy potentials for the northeast of Brazil. The hydrogen produced would be exported to countries which do not presently have significant renewable energy sources, but are willing to introduce those sources in their energy system. Hydrogen production was evaluated to be around 56.26 × 10⁶ m³ H₂/yr at a cost of 10.3 US$/kg.     

A solar and wind driven energy system for hydrogen and urea production with CO2 capturing

A novel solar PV and wind energy based system is proposed in this study for capturing carbon dioxide as well as producing hydrogen, urea and power. Both Aspen Plus and EES software packages are employed for analyses and simulations. The present system is designed in a way that PEM electrolyzer is powered by the wind turbines for hydrogen production, which is further converted into ammonia and then synthesizes urea by capturing CO₂ and additional power is supplied to the community. The solar PV is employed to power the cryogenic air separation unit and the additional power is used for the industrial purpose. In the proposed system, ammonia does not only capture CO₂ but also synthesizes urea for fertilizer industry. The amount of electrical power produced by the system is 2.14 MW. The designed system produces 518.4 kmol/d of hydrogen and synthesizes 86.4 kmol/d of urea. Furthermore, several parametric studies are employed to investigate the system performance.