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A Review of Wind-Resource-Assessment Technology
Abstract
Generation of electrical energy from wind can be economically achieved only where a significant wind resource exists. Because of the cubic relationship between wind velocity and output energy, sites with small percentage differences in average wind speeds can have substantial differences in available energy. Therefore, accurate and thorough monitoring of wind resource at potential sites is a critical factor in the siting of wind turbines. An accurately measured wind-speed frequency spectrum at a site is another important factor. For assessment of the wind-power potential of a site, most investigators have used simple wind-speed distributions that are parametrized solely by the arithmetic mean of the wind speed. Assessment of power output of a wind turbine will be accurate if the wind speeds measured at the hub height (30-50 m) of a wind turbine-generator are known. However, the existing wind data available at most of the meteorological stations worldwide is measured at a height of 10 or 20 m above the ground. Therefore, wind speeds measured at anemometer heights are extrapolated to the hub height of the wind turbine. Many investigators have proposed simple expressions for height extrapolation of wind speeds. This paper reviews wind-speed prediction and forecasting, and development of techniques for accurate assessment of wind-power potential. Also, the need of wind-resource assessment and the techniques and methods used for it are highlighted.
... Other studies focus on the history of wind turbines [13] and global developments of wind energy diffusion in recent years [14]. A large stream of research deals with the forecasting of wind power generation or meteorological aspects, such as wind speeds, and has already resulted in many reviews [15][16][17][18][19]. Further reviews deal with onshore wind related to markets [20], environmental impacts [21], or detailed technical resource assessments of individual wind turbines in specific locations [22,23] such as urban environments [24]. ...
... Reviews of onshore wind potentials have mostly examined studies on specific aspects, such as the system integration of wind turbines, e.g., in electricity grid analyses [25] or energy system planning models [26]. There are also review studies that address onshore wind potential assessments in general, but usually only in a short section and mainly with a focus on the geographical potential [15,27,28]. Others have reviewed methods and tools for onshore wind potential assessments in the context of the broader spectrum of renewable resources, whilst focussing mainly on the technical aspects [29]. ...
The rapid uptake of renewable energy technologies in recent decades has increased the demand of energy researchers, policymakers and energy planners for reliable data on the spatial distribution of their costs and potentials. For onshore wind energy this has resulted in an active research field devoted to analysing these resources for regions, countries or globally. A particular thread of this research attempts to go beyond purely technical or spatial restrictions and determine the realistic, feasible or actual potential for wind energy. Motivated by these developments, this paper reviews methods and assumptions for analysing geographical, technical, economic and, finally, feasible onshore wind potentials. We address each of these potentials in turn, including aspects related to land eligibility criteria, energy meteorology, and technical developments relating to wind turbine characteristics such as power density, specific rotor power and spacing aspects. Economic aspects of potential assessments are central to future deployment and are discussed on a turbine and system level covering levelized costs depending on locations, and the system integration costs which are often overlooked in such analyses. Non-technical approaches include scenicness assessments of the landscape, expert and stakeholder workshops, willingness to pay / accept elicitations and socioeconomic cost-benefit studies. For each of these different potential estimations, the state of the art is critically discussed, with an attempt to derive best practice recommendations and highlight avenues for future research.
... To collect relevant data of wind energy resources, a number of meteorological towers have been erected winthin a certain district of the wind farm according to local climate characteristics, topography and machine assembly capacity. Anemometers, wind vanes, and instruments for detecting temperature are installed on the meteorological towers, so that the wind condition in the wind farm can be continuously observed all the time [1] [2]. ...
... For each high-dimensional input sample I p , the output of the bottleneck layer neurons through the input layer and the bottleneck layer B p is shown in Eqs. (2): ...
... enewable energy sources are generally seen as cleaner than their nonrenewable counterparts (American Wind Energy Association [AWEA], 2008;Farhar & Coburn, 2008;IEA, 2008) and to a great extent considered socially desirable (ACORE, 2007; Inter Academy Council, 2007;REN21, 2008;Shoock, 2008;Zimmer, 2005;Zweibel & Mason, 2008) (Anthony & Goggin, 2008;S. Singh & Bhatti, 2006;Tucker, 2007), integration to the existing electric grid infrastructure (Langenkamp & Zedalis, 2006;Raven & Verbong, 2007), cost per kilowatt (Derbyshire, 2006;S. Wong, 2005), planning (Mander, 2007;Peltier, 2006;REN21, 2008;Toke, 2005; U.S. GAO, 2006), availability of financing and government incentives (Dennis-Escoffier & Falsetta, 200 ...
... situation with wind resources is further complicated by a combination of wind speeds and available technology, for wind under a certain threshold speed does not yield sufficient power to move windmill blades. Even though some progress has been made and nowadays more modern windmills can function at lower wind speeds, the literature (Peltier, 2006;S. Singh & Bhatti, 2006) notes this inability to ensure a constant flow of energy output represents a very serious threat to the viable commercialization of renewable energies. Alternatively, Peltier recommended we should no longer evaluate wind energy in its capability of meeting base load requirements, but rather we could look at it as an auxiliary power sour ...
Renewable energy resources (wind, solar, and geothermal energy) became
focus of attention in recent years. Even though they exhibit some very
desirable characteristics such as low carbon emission and mass appeal,
it is also true implementation of renewable energy sources face
formidable challenges. This paper will leverage the existing literature
and combine it with energy planner perspectives in order to consider
feasible ways to overcome key difficulties industry members face in
their effort to popularize wind and solar energy alternatives. This
study will also leverage specialists' knowledge in order to create a
shared vision of success to assist policymakers in their goal to reduce
the country's dependency on nonrenewable energy sources.
... Limited public access to information. Although published isopleth maps of wind energy across China are publicly available (Singh et al., 2006), there is limited public access to the more detailed wind resource data available in local meteorology bureaus. Wind resource data held by the National Meteorology Bureau and the Meteorology Institute were previously available on a fee-paying basis (Singh et al., 2006). ...
... Although published isopleth maps of wind energy across China are publicly available (Singh et al., 2006), there is limited public access to the more detailed wind resource data available in local meteorology bureaus. Wind resource data held by the National Meteorology Bureau and the Meteorology Institute were previously available on a fee-paying basis (Singh et al., 2006). Although data produced by state agencies have become increasingly transparent in recent years as a result of the central policy to enhance information transparency (Interview BJ/01/2006), non-state actors have still experienced limited access to the state-held data. ...
Wind power is potentially a key energy option that can assist China in meeting its sustainability goals but at present plays only a limited role in the country's energy system. Wind resource assessment (WRA) has been identified as a key impediment to the further development of this energy source. This paper examines whether collaborative governance can help to improve WRA in China, and if so through what mechanisms.
Collaborative initiatives involving WRA in two Chinese provinces, Xinjiang and Guangdong, are reviewed. This suggests that, while the central government has an important role to play, there are many opportunities for locally based collaborative initiatives to function as an alternative, complementary approach to facilitate WRA. Contextual elements such as local resources (including leadership and local knowledge) and governance structures (such as social networks) are identified as key conditions facilitating collaboration. The paper concludes that a broader perspective placing more emphasis beyond the central government in capacity building for WRA is required to enhance the prospects for the transition to a more sustainable energy system in China. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
... Early settlers in the country, who were predominantly farmers, relied on wind energy for many years to pump water for irrigation and domestic purposes. These farmers' exceptional agricultural yields were made possible by this method [55]. The country's energy mix has, however, largely relied on coal because of its low cost and wide availability, making the integration of wind energy difficult. ...
Renewable energy has emerged as a promising solution to address the challenges of climate change, energy security, and socio-economic development. South Africa, with its abundant renewable energy resources, has made significant strides in the utilization of renewable energy over the past decade. This paper provides a comprehensive review of the progress of renewable energy advancement in South Africa, examining the policies, initiatives, and achievements in various renewable energy sectors. This study explores the country’s transition from a heavily coal-dependent energy system to a diversified and sustainable energy mix. It analyses the growth of renewable energy technologies, such as wind power and solar photovoltaic (PV), highlighting the key milestones, challenges, and opportunities. Furthermore, this paper discusses the role of government support, regulatory frameworks, and private sector investments in driving renewable energy deployment in South Africa. Finally, it identifies the prospects and potential areas for further advancement in the renewable energy sector. This review aims to contribute to the understanding of South Africa’s renewable energy journey and provides valuable insights for policy-makers, researchers, and stakeholders involved in the sustainable energy transition.
... 39 Still others analyze performance, critique policies, or present pathways to achieve high levels of renewable energy penetration but do not develop potential estimates of their own or evaluate site suitability. [40][41][42][43][44][45][46][47][48][49][50] Overall, insights from previous studies are limited in granularity due to the use of lower-resolution data and altitudes, which this study addresses. Studies before 2020 primarily measure wind speeds at 50, 80, or 100 m, [22][23][24]28,37,51,52 while more recent studies up to 2023 use hub heights no greater than 120 m. [25][26][27] By contrast, this study estimates potential at 150 and 200 m to represent contemporary and future turbines. ...
... Since the amount of power generated by a wind turbine is affected by wind resources in the installation area, accurate wind resource forecasting is essential in selecting a wind farm site [6,7]. The numerical weather prediction (NWP) method predicts future weather conditions based on current weather conditions by solving numerical models of the atmosphere and oceans. ...
The numerical weather prediction (NWP) method is one of the popular wind resource forecasting methods, but it has the limitation that it does not consider the influence of local topography. The NWP-CFD downscaling considers topographic features and surface roughness by performing computational fluid dynamics (CFD) with the meteorological data obtained by the NWP method as a boundary condition. The NWP-CFD downscaling is expected to be suitable for wind resource forecasting in Korea, but it lacks a quantitative evaluation of its reliability. In this study, we compare the actual measured data, the NWP-based data, and the NWP-CFD-based data quantitatively and analyze the three main input parameters used for the calculation of NWP-CFD (minimum vertical grid size ∆z min , the difference angle ∆dir, and the forest model activation reference length l 0). Compared to the actual measurement data, the NWP-based data overestimate wind resources by more than 35%, while the NWP-CFD-based data show an error of about 8.5%. The ∆z min and ∆dir have little effect on the results, but the l 0 has a large effect on the simulation results, and it is necessary to adjust the values appropriately corresponding to the characteristics of an area.
... In the past years, the number of resource assessment research studies, especially for wind energy, has increased. The studies and review papers focused on several aspects of improving methods for site assessment (Kelledy, 1982;Troen and Lundtang Petersen, 1989;Bailey et al., 1997;Truhetz et al., 2007;Lackner et al., 2008) and/or prediction of production for both on shore and offshore wind energy such as land-use mapping, social constraints (Schallenberg-Rodriguez, 2013;Höltinger et al., 2016;Jäger et al., 2016;Harper et al., 2019), or improving atmospheric and climate models (Singh et al., 2006;Zhang et al., 2014;Widén et al., 2015;Gualtieri, 2019;Yang et al., 2021). ...
Introduction
With hydropower being the dominant source of renewable energy in Austria and recent years being disproportionally dry, alternative renewable energy sources need to be tapped to compensate for the reduction of fossil fuels and account for dry conditions. This becomes even more important given the current geopolitical situation. Wind power plays an essential role in decarbonizing Austria's electricity system. For local assessments of historic, recent, and future wind conditions, adequate climate data are essential. Reanalysis data, often used for such assessments, have a coarse spatial resolution and could be unable to capture local wind features relevant for wind power modeling. Thus, raw reanalysis data need post-processing, and the results need to be interpreted with care. The purpose of this study is to assess the quality of three reanalysis data sets, such as MERRA-2, ERA5, and COSMO-REA6, for both surface level and hub height wind speed and wind power production at meteorological observation sites and wind farms in flat and mountainous terrain. Furthermore, the study aims at providing a first knowledge baseline toward generating a novel wind speed and wind power atlas at different hub heights for Austria with a spatial resolution of 1 × 1 km and for an experimental region with sub-km resolution. Thus, the study tries to answer (i) the questions if the reanalysis and analysis data can reproduce surface-level wind speed and (ii) if wind power calculations based on these data can be trusted, providing a knowledge base for future wind speed and wind power applications in complex terrain.
Methods
For that purpose, a generalized additive model (GAM) is applied to enable a data-driven gridded surface wind speed analysis as well as extrapolation to hub heights as a first step toward generating a novel wind speed atlas. In addition, to account for errors due to the coarse grid of the re-analysis, the New European Wind Atlas (NEWA) and the Global Wind Atlas (GWA) are used for correction using an hourly correction factor accounting for diurnal variations. For the analysis of wind power, an empirical turbine power curve approach was facilitated and applied to five different wind sites in Austria.
Results and discussion
The results showed that for surface-level wind speed, the GAM outperforms the reanalysis data sets across all altitude levels with a mean average error (MAE) of 1.65 m/s for the meteorological sites. It even outperforms the NEWA wind atlas, which has an MAE of 3.78 m/s. For flat regions, the raw reanalysis matches the production data better than NEWA, also for hub height wind speeds, following wind power. For the mountainous areas, a correction of the reanalysis data based on the NEWA climatology, or even the NEWA climatology itself, significantly improved wind power evaluations. Comparisons between modeled wind power time series and real data show mean absolute errors of 8% of the nominal power in flat terrain and 14 or 17% in mountainous terrain.
... However the lidar output is usually intermittent with large unavailability at offshore locations. Contrarily, numerical weather prediction (NWP) models offer output that covers large geographical areas and long-time horizons simultaneously and continuously, but the data are of a significantly lower fidelity [7]. ...
In the pre-construction of wind farms, wind resource assessment is of paramount importance. Measurements by lidars are a source of high-fidelity data. However, they are expensive and sparse in space and time. Contrarily, Weather Research and Forecasting models generate continuous data with relatively low fidelity. We propose a hybrid approach combining measurements and output from numerical simulations for the assessment of offshore wind. Firstly, the datasets were fed onto a matrix, with columns representing the spatial lidar and WRF points, and the rows representing the time steps. Entries of the matrix reflect the wind speed, empty entries represent unobserved data. Then, matrix factorization using Gaussian process was employed for filling the missing entries with statistically calculated estimates. The model was optimized with stochastic gradient descent to apply GP without approximation methods. To evaluate the method, wind speed data along the coast of Denmark were used. The proposed technique, evaluated using two experiments, resulted in 58% more accurate results than the industrial standard method with trivial increase of computational cost. The RMSE of the proposed method ranges between 0.35 and 0.52 m/s.
... Wind resource maps are essential for planning and making decisions related to wind energy; thus, there have been many studies to create high-quality maps of various regions. [1][2][3] In particular, high-resolution wind resource maps with a resolution over 1 km are necessary for many fields such as policy and industry. 4 Maps with lower resolution are difficult to use in practical cases because they do not sufficiently consider the effect of the terrain. ...
The need for high-resolution wind resource maps is increasing with the increase in the supply and development of wind power. Many physical downscaling models have been developed and applied to make these maps. However, as the existing models require extensive computations and time, statistical models with higher efficiency are being studied. Statistical models such as regression and machine learning models can quickly calculate wind resource maps, but they have a problem of low accuracy. This study proposes a machine learning model with new topography-derived variables to interpret the physical characteristics of the wind. As the shape of topography, which was unable to be interpreted in previous studies, can be considered with new derived variables, a significant performance improvement was identified. The analysis was conducted using 1 km Weather Research and Forecasting (WRF) results and ERA5 reanalysis data from South Korea. Two Weibull distribution parameter maps were calculated and used as input and output data. Three collections of derived variables were devised and compared. Therefore, the multi-resolution topography data showed the highest improvements with approximately 15% reduction in root mean square error (RMSE) for both the linear regression and machine learning models. In particular, the land area showed a decrease of 20%. The best proposed models showed an RMSE of 7% and 8% for two Weibull parameters. The results are expected to serve as a reference for continuing research and utilization of statistical models.
... Wind power density varies directly with wind speed, so small differences can lead to significant differences in energy estimates. Accurate estimation of the wind resources present at a particular location is very important (Singh et al., 2006). Modeling Pdf at WS with Weibull two parameters (W2) is more significant (Chang, 2011), (Werapun et al., 2015). ...
Wind speed (WS) is important information to determine the potential for wind energy in an area. Wind speed has been widely expressed by the probability density function (Pdf), one of which uses the Weibull Distribution (WD). Not all WS data can be analyzed by WD because some deficiencies need to be corrected. Modified Weibull Distribution (MWD) is proposed to improve the existing WD models. In addition, this paper also compares the performance of MWD against WD using WS data measured in Medan City. To validate the two models (WD and MWD), the coefficient of determination (R-squared) and the mean square root error (RMSE) were used. In addition, data validation tests were also carried out using Chi-square and Kolmogorov-Smirnov. The result obtained is that MWD has a more acceptable fit than WD for this case.
Keywords: Wind speed, Distribution function, Weibull distribution, Modified Weibull distribution
JEL Classifications: C13; C22; C36; C93; L94; Q42
DOI: https://doi.org/10.32479/ijeep.11625
... Reviews of onshore wind potentials have mostly examined studies on specific aspects, such as the system integration of wind turbines, e.g., in electricity grid analyses [21] or energy system planning models [22]. There are also review studies that address onshore wind potential assessments in general, but usually only in a short section and mainly with a focus on the geographical potential [11,23,24]. Others have reviewed methods and tools for onshore wind potential assessments in the context of the broader spectrum of renewable resources, whilst focussing mainly on the technical aspects [25]. ...
The rapid uptake of renewable energy technologies in recent decades has increased the demand of energy researchers, policymakers and energy planners for reliable data on the spatial distribution of their costs and potentials. For onshore wind energy this has resulted in an active research field devoted to analysing these resources for regions, countries or globally. A particular thread of this research attempts to go beyond purely technical or spatial restrictions and determine the realistic, feasible or actual potential for wind energy. Motivated by these developments, this paper reviews methods and assumptions for analysing geographical, technical, economic and, finally, feasible onshore wind potentials. We address each of these potentials in turn, including aspects related to land eligibility criteria, energy meteorology, and technical developments relating to wind turbine characteristics such as power density, specific rotor power and spacing aspects. Economic aspects of potential assessments are central to future deployment and are discussed on a turbine and system level covering levelized costs depending on locations, and the system integration costs which are often overlooked in such analyses. Non-technical approaches include scenicness assessments of the landscape, constraints due to regulation or public opposition, expert and stakeholder workshops, willingness to pay/accept elicitations and socioeconomic cost-benefit studies. For each of these different potential estimations, the state of the art is critically discussed, with an attempt to derive best practice recommendations and highlight avenues for future research.
... Wind shear is the change in horizontal wind speed with height (Singh, Bhatti, and Kothari 2006), which is highly affected by site location for first 100 m (Schallenberg-Rodriguez 2013). Wind shear depends on wind speed, temperature, height interval, atmospheric stability, surface roughness, season of the year, etc. (Spera 1994). ...
This study aims to evaluate wind resource potential and analyze the performance of wind turbines for six onshore and near-coast sites (three commercial power plants and three new potential sites) of Pakistan. The technical and economic performance analysis of more than 200 commercially available turbines suitable for weak wind regions is performed, 20 turbines were selected based on performance. The percentage increase in annual Capacity Factor (CF) and decrease in Levelized Cost of Electricity (LCOE) for commercial sites using proposed turbine is 42–61% and 30–38% respectively compared to installed turbines on the sites. Three potential sites have wind power density as 155, 203, and 237 W/m² and corresponding wind power class as poor, marginal and marginal respectively. The CF and LCOE of potential sites having marginal power class using PT10 turbine (Goldwind GW140/3.0) is up to 50% and 5.5 US¢/kWh respectively so these two sites are economically feasible for future wind projects. The CF and LCOE of potential sites having poor power class using PT10 turbine is 34% and 7.2 US¢/kWh. The wind turbines having lower cut-in wind speed and lower-rated wind speeds are economically feasible for sites having poor wind power class.
... sing complexity W. Langreder(2010). The measurements can be done by fixing the suitable sensors at different heights on the mast. The criterion for determining wind-energy potential is based on a simple set of parameters, including average wind-energy density W/m 2, annual hours of wind speed above 6 m/s, and annual hours of wind speed above 3 m/s Sh. Singh (2006). By installing a large number of masts in a wide area in the middle and south of Iraq, the records of wind speed and direction, as well as other meteorological data for each site, will be obtained. The obtained data can be drawn in GIS map, to determine the sites that have superior wind speeds. These sites will be efficient if they have ...
... Therefore, accurate estimation of existing wind resource at a particular location is crucial. (Singh et al., 2006). ...
The objective of current work is to compare a newly developed method i.e. Wind Energy Intensification Method (WEIM) with two previously used methods i.e. Maximum Likelihood Method (MLM) and Modified Maximum Likelihood Method (MMLM) to calculate Weibull shape and scale parameters. Three Years (2014–2017) hourly measured wind data at 50 m mast height has been used at sixty locations in Pakistan. These methods have been compared with the help of Wind Energy Error (WEE), RMSE and R². It has been found that WEIM is the most accurate method while MMLM is the second most accurate. Moreover, a comparison of energy density values estimated using actual wind speed distribution and Weibull distribution with three methods has been conducted, and it is found that WEIM estimates the energy density values which are closest to actual values among three methods at each location. Hence, WEIM can be used with significant accuracy for Weibull parameters determination. Finally, province-wise comparison of energy density values for investigated locations has been done which shows that Chaghi, DI Khan, Rahim Yar Khan and Thatta are the most lucrative sites in each of four provinces.
... (Stull, 1988) It is due to turbulent momentum flux (i.e., Reynolds stress) that the effect of the ever changing surface forcings is transmitted throughout the boundary layer (Stull, 1988). In wind power meteorology, a turbulence intensity factor (TI), based on the standard deviation of the wind speed, is the most commonly used indicator of turbulence (Singh, Bhatti, & Kothari, 2006). In boundary layer meteorology, turbulence kinetic energy (TKE) is used to more fully define the variance. ...
p>The assessment of urban morphology-induced wind amplification, specifically in support of siting building-integrated and/or mounted Urban Wind Energy Conversion Systems (UWECSs), is a very recent undertaking. Only a small number of wind turbine manufacturers are even exploring the development of suitably-scaled devices whose performance characteristics are tailored to urban wind conditions. As such, this research explored the feasibility of the building augmented wind turbine (BAWT)-theory in an urban setting through the development of a prototype Urban Wind Energy Planning (UWEP) Decision Support System (DSS).
The prototype UWEP DSS focuses primarily on building aerodynamics-induced wind amplification, including consideration of peak-wind seasons. Microsoft® Excel was selected as the platform for the UWEP DSS, supporting development of user forms and integral databases. This tool is intended for a broad range of users, including the average home owner, UWECS developers, and energy planners. With minimal user input, the UWEP DSS determines the mean wind speed within the amplification zones, the location of the amplification zones, and the energy that could potentially be generated by an appropriately-sited UWECS.
Two case study applications of the UWEP DSS were conducted to validate the estimations and demonstrate the capabilities of the tool. The University of Toronto Robarts Library application and the Green Venture EcoHouse application yielded credible mean wind speed and potential wind energy estimates on comparison to the online wind atlases. The EcoHouse case study application included the selection and siting of various UWECSs. It highlighted the potential of a hypothetical wind energy conversion device being able to generate almost 40% of the 700 kWh per month, average household energy demand.
Conversely, it demonstrated that the traditional tower-mounted horizontal axis wind turbines, situated outside of the potential amplification zones in accordance with current siting guidelines, would only be able to generate 5% of the demand.
By demonstrating the prototype UWEP DSS through an institutional and a residential application case study, it is hoped that the scope and capabilities of, and the amplified wind energy potential identified by, this tool will foster further research in urban wind energy planning, building aerodynamics-induced amplification assessment, and development of new UWECSs.
The prototype UWEP DSS appears to be the first to estimate building aerodynamics-induced amplification from peak composite pressure-gust coefficients published in building codes. Further research is recommended to gain a better understanding of sustained, as opposed to peak, wind amplification. The modular nature of the UWEP DSS lends itself to the modifications that will undoubtedly be required as further knowledge is developed in this field.</p
... Accurate wind resource assessments are crucial to the successful development of wind farms (Singh et al., 2006). In common practice, the data acquisition system should have a sampling rate of the wind speed at least 0.5 Hz (one measurement per 2 seconds). ...
Wind turbine for low power applications is a clean energy alternative to contribute global warming mitigation. The correct description of wind speeds is crucial to determine the economic viability of a wind power project. The sampling technique used in resource assessment is supported by van der Hoven's work, which concludes that minimum dispersion occurs between 0.1 and 2. hours mean time. International standards for wind turbine power characterization are also based on this work. Here we analyze the influence of using different mean times over data dispersion and wind resource assessment and analyze an adequate mean time for small wind turbine (SWT) applications that contributes to the development of reliable resource assessments. We found a maximum dispersion around 1. minute mean time. The stable wind conditions region was not found in the dispersion analysis presented here. Using this time in SWT resource assessment will detect the largest amount of changes in the time series that may contribute to power production. Resource assessments calculated show that using 1 and 10. minutes as mean times generates power resource assessments with a difference around 17%, which may be a factor that prevents SWT penetration. There exist at least two factors to obtain reliable power resource assessment, the SWT selection and ensemble mean time.
... Throughout the 20-year lifespan of a wind turbine, particles such as rain, sand, ice crystals, hail, and insects are major contributors to a deterioration in turbine performances through local airfoil surface alterations. [1][2][3][4][5][6] Wind turbine blades accumulate dirt especially in the surroundings of the leading edge. Moreover particle collision, temperature jumps and freeze-thaw cycles may cause smaller coating cracks to propagate, promoting coating removal and eventually delamination and corrosion damage due to exposure of the internal composite structure. ...
A numerical study of how to simulate heavy atmospheric particle collisions with a 38-m, 1.5-MW horizontal axis wind turbine blade is discussed. Two types of particles were considered, namely hailstones and rain drops. Computations were performed by using a two-dimensional inviscid flowfield solver along with a particle position predictor code. Three blade sections were considered: at 35% span and characterized by a DU 97-W-300 airfoil, at 70% span with a DU 96-W-212 airfoil, and at 90% span using a DU 96-W-180 airfoil. The three blade sections are constituted by 8-ply carbon/epoxy panels, coated with ultra-high molecular weight polyethylene (UHMWPE). Hailstone and raindrop simulations were performed to estimate the location of the striking occurrences and the blade surface area subject to damage. Results show that the impact locations along the blade are a function of airfoil angle of attack, local relative velocity, airfoil shape, aerodynamics and mass of the particle. Hailstones were found to collide on nearly every portion of the blade section along their trajectory due to their insensitivity to the blade flowfield. The damaged surface areas were found to be small when compared to the overall impingement surface, and most of delamination damage was localized on the blade leading edge. Moreover, panel delamination occurred for outboard sections, when r=R 0.90. The damage due to raindrops was divided in an erosive and a fatigue contribution due to the impact force. It was observed that the erosive damage follows the cubic power of the blade velocity, whereas the impact force follows the square power of the blade velocity. Moreover, it was seen that the rain drops are sensitive to the blade flowfield, due to shape modifications through the Weber number. In particular, a sensitive behavior of the damage with respect to the blade angle of attack was observed.
... Renewable energy is considered to be the most promising alternative energy resource and plays a significant role in securing a longterm sustainable energy supply, mainly because of needs for higher power quality, lower costs, and smaller environmental footprints (Fyrippis et al. 2010;Glasnovic and Margeta 2010;Moghaddam et al. 2011). As the most active member of this group, wind power demonstrates considerable benefits and good potential (Singh et al. 2006;Zhao et al. 2014). Currently, wind-related forecasting techniques have become a focal point for many studies (Duran et al. 2007), since the development of wind power generation requires accurate information regarding wind resources, especially regional wind speeds. ...
Since wind fluctuates with strong variation even within a short-term period, it is quite
difficult to describe the characteristics of wind or to estimate the power output that will
be injected into the grid. In particular, short-term wind speed forecasting, an essential
support for the regulatory actions and short-term load dispatching planning during the
operation of wind farms, is currently regarded as one of the most difficult problems to
be solved. This paper contributes to multi-step forecasting for short-term wind speed by
developing a three-stage hybrid approach, named MECE; it is a combination of the
ensemble empirical model decomposition (EEMD) method, cuckoo search (CS)
algorithm and extreme learning machine (ELM) method. As the first stage of the hybrid
MECE approach, a signal filtering based on a decomposition & reconstruction strategy
is adopted and coped by EEMD method, and a de-noised series can be obtained.
Then, the CS-optimized ELM is designed as a novel learning method to construct a
single layer feed-forward neural network (SLFN), the input weights and biases are
determined by CS algorithm instead of the randomly initialization within the original
ELM. Next, a training & forecasting stage is taken; three different strategies are
adopted for multi-step forecasting. The chosen data sets are half-hour wind speed
observations, including sixteen samples, and the simulation indicates that the
proposed MECE approach performs much better than the traditional ones when
addressing short-term wind speed forecasting problems.
... Resource assessments are based on weather records and the technical characteristics of the renewable source. This also applies to wind power as a renewable energy source; therefore, the development of accurate and meticulous methods for measuring and monitoring wind speeds are critical factors in its implementation [1]. ...
Estimating the power output is one of the elements that determine the techno-economic feasibility of a renewable project. At present, there is a need to develop reliable methods that achieve this goal, thereby contributing to wind power penetration. In this study, we propose a method for wind power error estimation based on the wind speed measurement error, probability density function, and wind turbine power curves. This method uses the actual wind speed data without prior statistical treatment based on 28 wind turbine power curves, which were fitted by Lagrange's method, to calculate the estimate wind power output and the corresponding error propagation. We found that wind speed percentage errors of 10% were propagated into the power output estimates, thereby yielding an error of 5%. The proposed error propagation complements the traditional power resource assessments. The wind power estimation error also allows us to estimate intervals for the power production leveled cost or the investment time return. The implementation of this method increases the reliability of techno-economic resource assessment studies.
... Environmental pollution and greenhouse effects are major concerns related to fossil-fuel-based energy sources. Therefore, renewable and alternative energy sources, such as solar energy (Susheela and Sharp 2001;Othman et al. 2006;Ozturk 2007;Sopian et al. 2007;Tan et al. 2012), wind energy (Singh et al. 2006; Lee and Tzeng 2008;Oh and Short 2009;Kusiak et al. 2011), hydro energy (Gordon et al. 1986), geothermal energy (Phetteplace 2007), biofuel (Brown and Hu 2012), biomass (Panwar et al. 2011;Kinoshita et al. 1997), hydrogen, and fuel cell technologies (Wu and Zhou 2012;Kern and Feldman 1984;Chiang et al. 2012) have received much attention in recent years. Fuel cells have emerged as a potential source of green energy and have been widely investigated around the globe in recent years. ...
A one-dimensional, nonisothermal model for passive direct methanol fuel cells (DMFCs) is developed. The coupled heat and mass transport, along with electrochemical reactions, are considered in the model. Cell performance for different methanol feed concentrations is evaluated. The reason for improved fuel cell performance at increased methanol feed concentrations is investigated and explained. Variations in cell operating temperature, heat generation rate at the anode catalyst layer (ACL), and at the cathode catalyst layer (CCL) are critically analyzed in this connection. It is found that the ACL temperature, referred to as the cell operating temperature, has a crucial effect on passive DMFC performance. The increased cell operating temperature at higher methanol feed concentration is responsible for better cell performance. The results of this work will be useful for optimizing the thermal management and achieving better performance of passive DMFCs.
In wind resource assessments, which are critical to the pre-construction of wind farms, measurements by lidars or masts are a source of high-fidelity data, but are expensive and scarce in space and time, particularly for offshore sites. On the other hand, numerical simulations, using for example the Weather Research and Forecasting (WRF) model, generate temporally and spatially continuous data with relatively low-fidelity. A hybrid approach is proposed here to combine the merit of measurements and simulations for the assessment of offshore wind. Firstly a temporal data fusion using deep Multi Fidelity Gaussian Process Regression (MF-GPR) is performed to combine the intermittent measurement and the continuous simulation data at an onshore location. Then a spatial data fusion using a neural network with Non-linear Autoregression (NAR) and Non-linear Autoregression with external input (NARX) are conducted to project the wind from onshore to offshore. The numerical and measured wind speeds along the west coast of Denmark were used to evaluate the method. We show that the proposed data fusion technique using a gappy onshore measurement results in accurate offshore wind resource assessment within a 2% margin error.
Short Term Wind Speed Forecasting with ANN in Jiroft - Iran
The warning of irreversible climate change, safety of nuclear plants and volatile fuel prices are forcing the entire world to concentrate on clean energy sources. Recently, the government of India shows interest in renewable energy development due to an anti-nuclear agitation by the people's movement against nuclear energy after Fukushima nuclear disaster 2011. However, a major problem for wind energy industry and marketing is to find potential sites to install wind turbines. In this study, suitable sites were identified based on technical, economical, and environmental criteria using open source geographical information system for Coimbatore North Taluk and Annur Taluk of Tamil Nadu, India. Boolean logic analysis was used for vector overlay operations, fuzzy logic analysis were used for raster overlay operations. The potential locations for the wind farms were estimated for each suitability class by using integrated Boolean and fuzzy logic analysis, 5.74% of the study area selected as highly suitable and 1.84% of the study area was selected as suitable sites for wind farm development. The majority of suitable area was located in North of the study area, where energy demand is lesser than other places.
A review of the wind resource assessment methodologies and an overview of numerical models are undertaken in this paper with stress laid on the preliminary estimation using local trees and vegetation as biological indicators of wind potential at site. Present review consists of the various methods and strategies used by the earlier researchers for assessing the wind resource at any region. Besides, the utilisation of advanced numerical weather prediction models is also discussed. Further several regional case studies are also presented which have been done using mesoscale and other wind climate prediction models worldwide. Moreover, the wind shear profile estimation using linear and non-linear models are also described. Also the review of the comparison studies between WAsP and CFD mesoscale models in evaluating the wind profiles at different locations is been done.
The selection of suitable geographic locations for wind farms can be challenging due to the various agents involved in the process, such as, environmentalists, investors, government agencies, and utilities. In addition, selection criteria differ depending on the agents preferences. The site selection process considers the factors and constraints posed by these agents, such as technical (wind power density), physical (safe distance to air force station, roads, and transmission lines), economic (terrain slope), social (settlements and hospitals), and environmental (forests, lakes, ponds, and streams). Geographical information system (GIS) is a powerful tool for enhancing spatial decisions. A combination of Boolean logic, fuzzy logic, and the weighted product method is used in GIS to identify feasible locations. Further simplification of the entire geo-processing operation is modification into a single operation using a geo-processing modeller in an open source QGIS software environment. This study determined that the most suitable locations for wind farms are in close proximity to urban areas within the study area of Palladam Taluk, India.
The wind resource data from a potential site in northwest China were monitored and transmitted remotely based on the GPRS wireless communication principle, and were processed through Excel VBA programming, coming to form a regular table of weather stations. It is found that there are some missing and false data in the process of statistics and analysis of the data, thus those data were mended by the reasonable equation of correlation, which is from the comparison between the data from the observing point and the same period ones from the near weather station through the correlation analysis method. Finally, it can draw the conclusion that the annual wind resource at a potential site in this area belongs to the available area of wind energy according to the law of two Weibull distributions.
Wind speed simulation is one of the most important means in wind power generation studies. After a brief outline of wind characteristic studies, the paper presents a short-term wind speed simulation model based on Kaimal's wind speed power spectrum. The simulated wind speed series were compared to field measured wind speed time series. The results showed good performance for simulation collectivity from the model, while it failed to reflect the specific wind speed fluctuation characteristic related to the simulated site. Hence, the paper proposed a method that employs the field measured wind speed to correct the simulated wind speed. After correcting, the simulated wind speed series not only possessed good performance for simulation collectivity, but reflected excellently the specific site characteristic wind speed fluctuation as well. The proposed method enormously improved the performance of the model. The proposed model and method should be useful in a wide area of studies, such as short-term wind speed forecasting, wind turbine dynamic simulation, wind generation system control, wind power quality analysis, and other wind engineering or signal analysis.
Current dependency on finite reserves fossil fuels and adverse environmental effects of conventional power system created new dimension interest in renewable energy sources toward building a sustainable and reliable energy in the near future. Wind energy is renewable and considered as one of the safest, cleanest and fastest growing forms of renewable energy in the world. Generation of electrical energy from wind can only be possible where there is considerable wind resource exists. For this reasons an accurate wind resource evaluation is a vital tool for harnessing energy content in a wind. This paper is critically reviews different techniques used in wind resource assessment, prospects and challenges of utilizing wind energy in some developed and developing countries; however recent progress and development of wind energy potential and utilizations in the countries neighboring Malaysia are discussed. Several recent wind energy potential studies, areas that are suitable for exploitation of wind energy for electrical power generation as well as the current situation of wind energy utilization in Malaysia and possible recommendations were presented.
The Investigation on SRTM and ASTER Terrain Data for Wind Energy Resource Assessment An adequate height contour map is one of essential data for an accurate wind energy assessment. The map area is usually required to extend to at least 5 km from the boundary of calculation site. SRTM (Shuttle Radar Terrain Mission) and ASTER (Advanced Space borne Thermal Emission and Reflection Radiometer) provide global digital elevation data with high resolution were released to public free in resent year. The coverage of SRTM is from 56° S to 60° N with a global resolution of 90 m. ASTER has a more complete coverage from 83 ° S to 83° N of the earth and a better global resolution of 30 m. Kingman Island near to China with a distance less than 2 km was selected as an area of case study. The differences between the elevations of the two satellite digital elevation models of Kingman Island are calculated. The elevations of SRTM are usually higher than ASTER when the elevation is above 20 m. The wind energy resource assessment results of ASTER are much higher than the SRTM. The average wind speed is about 10% and the power density about 30%. The results may be inferred that the higher resolution of ASTER terrain data. This study also tried to evaluate the terrain effect of neighboring area on the wind energy resource assessment of Kingman Island by using SRTM terrain data. As anticipation, the terrain effect could cause the decrease of wind resource of Kingman Island.
Wind energy represents an important energy source and, even more, it is called to play a crucial role in the future energy supply. In this context, it is crucial to estimate the technical and economical wind energy potential in different regions and areas. This paper includes an extensive review of methodologies proposed by several authors. Based on this review, a set of equations for the evaluation of wind energy production in a given area is proposed, being the input data: mean wind speed and shape factor at any height or even just the mean wind speed. To calculate the wind energy production, wind farm configuration (array efficiency/wake losses) and extrapolation/interpolation of wind speed and shape factor of Weibull distribution to the hub height, have been the main issues discussed. The distances among wind turbines are determined according to economic criteria, where two different approaches have been considered: maximizing income or minimizing cost per kWh. Available wind data usually include mean wind speed and shape factor at certain heights but, very often, not at the hub height. Several methods for extra/interpolation of wind speed and shape factor have been reviewed and a set of equations has been proposed to calculate them at the hub height. A methodology to calculate the annualized wind generation cost (c(sic)/kWh) is also proposed. One of the premises of this methodology has been that calculations should be able to be done simply using calculator and common office software programs. Another premise has been that the methodology proposed is not meant for a detailed evaluation of energy production of one particular windfarm, but to establish a general methodology to study relatively big areas, like islands or whole regions. A practical application of the methodology proposed has been carried out using wind data from the Canary Islands.
This paper introduces the frequency domain approach to characterize and analyze wind speed patterns. It first presents the technique of and the prerequisite conditions for the frequency domain approach. Three years of wind speed data at 10 different locations have been used. This paper demonstrates that wind speed patterns during different times and at different locations can be well characterized by using the frequency domain approach with its compact and structured format. We also perform analysis using the characterized dataset. It affirms that the frequency domain approach is a useful indicator for understanding the characteristics of wind speed patterns and can express the information with superior accuracy.
This paper describes the analytical and modelling methods employed in a Wind Resource Assessment (WRA) and reliability assessment of a Wind Energy Conversion System (WECS) for small island networks. A case study of the Caribbean island of Anguilla has been conducted. A detailed wind regime revealed a mean wind speed of 7.9 ms-1 for extrapolated heights 55 m and higher. Both analytical and modelling techniques technically justified the WECS with an annual production in excess of 5 GWh using appropriate turbines to satisfy the monthly energy generation profiles for Anguilla. The reliability assessment incorporated Monte Carlo Simulation (MCS) for outages of the generating units yielding the healthy, marginal and risk state probabilities. The system exhibited probabilities of health ≥ 0.999, while the LOLP ≤ 0.0005. The Falcon (1.25 MW) wind turbine yielded the best technical performance while the Unison U57 (0.75 MW) wind turbine was deemed suitable satisfying critical aesthetic requirements. An initial economic appraisal is also presented.
Energy is the prime mover of economic growth and is vital to sustain a modern economic and social development. Renewable energy applications have brought about significant changes in the Indian energy scenario. The identification and efficient use of various renewable energy resources are the thrust areas in energy development. Wind energy is one of the most environment friendly, clean and safe energy resources. The wind energy will continue to be the biggest renewable energy sector in any country in terms of both installed capacity and total potential. This paper reviews some important factors and techniques to be considered for wind turbine installations such as the wind energy resource assessment techniques, environmental factors, grid integration factors, control strategies, impact of offshore wind turbines and hybrid energy technologies, hydrogen production techniques, feed-in tariff mechanism, modeling of wind turbine components including generators, performance improvement techniques. The cost and economic feasibility of the wind energy conversion system as well as the control strategies of wind turbine generators have also been discussed.
Reducing atmospheric CO2 using a combination of air capture and offshore geological storage can address technical and policy concerns with climate mitigation. Because CO2 mixes rapidly in the atmosphere, air capture could operate anywhere and in principle reduce CO2 to pre-industrial levels. We investigate the Kerguelen plateau in the Indian Ocean, which offers steady wind resources, vast sub-seafloor storage capacities, and minimal risk of economic damages or human inconvenience and harm. The efficiency of humidity swing driven air capture under humid and windy conditions is tested in the laboratory. Powered by wind, we estimate ~75 Mt CO2/yr could be collected using air capture and sequestered below seafloor or partially used for synfuel. Our analysis suggests that Kerguelen offers a remote and environmentally secure location for CO2 sequestration using renewable energy. Regional reservoirs could hold over 1,500 Gt CO2, sequestering a large fraction of 21st century emissions.
IntroductionOverview of Economic Assessment of Wind Energy SystemsCapital Costs of Wind Energy SystemsOperation and Maintenance CostsValue of Wind EnergyEconomic Analysis Methods
Wind Energy Market ConsiderationsReferences
Bangladesh is suffering severely from power crisis in past few years. Fossil fuels are getting diminished day by day. Bangladesh should look for renewable sources of energy. Wind can be a solution to this problem. Wind is a good form of renewable energy. Bangladesh has a long coastal area. Wind blows in different patterns in different seasons. Wind turbines should have the capacity to withstand against 250 km/hr wind in coastal zones. Previously collected data have been analyzed to evaluate the potential of wind energy in different spots of Bangladesh. Feasibility to establish wind turbines in different zones in mass scale to produce electricity and for irrigation purpose are described briefly. Working principle and design considerations to install wind turbines are also discussed in this paper. Effect of height in average wind speed and probable power generation is shown here. An effort has been made to estimate the relevant costs regarding establishment of a wind turbine.
Wind data collected at ten stations in Malaysia were analysed for wind energy potential. The data were collected over a ten-year period (1982-1991). The results were presented as a Weibull distribution and analysis indicated that the station at Mersing has the greatest potential, with a mean power density of 85.61 W/m(2) at 10 m above sea level.
Mean wind data for 64 stations, 48 of which are located in Algeria and 16 in neighbouring countries has been used to establish the wind energy map of Algeria at a height of 10 m. It is found that the wind speed varies between 1 and 6 m/s. The windy regions are located at the west south of Algeria, in the Sahara. Statistical analysis of the data for 21 stations located at various topographic locations in Algeria have been carried out and the daily and yearly variations of wind speed have been established. The Weibull parameters and power density of the stations have been determined using the hybrid Weibull distribution. Finally, wind speeds obtained in Algeria prove that it is interesting to set up some wind systems for agricultural applications.
This paper describes the creation of a comprehensive wind energy resource atlas for the Philippines. The atlas was created to facilitate the rapid identification of good wind resource areas and understanding of the salient wind characteristics. Detailed wind resource maps were generated for the entire country using an advanced wind mapping technique and innovative assessment methods recently developed at the National Renewable Energy Laboratory.
The United States Department of Energy (DOE) and the United States Agency for International Development (USAID) sponsored a project to help accelerate the large-scale use of wind energy technologies in Mongolia through the development of a wind energy resource atlas of Mongolia. DOE's National Renewable Energy Laboratory (NREL) administered and conducted this project in collaboration with USAID and Mongolia. The Mongolian organizations participating in this project were the Scientific, Production, and Trade Corporation for Renewable Energy (REC) and the Institute of Meteorology and Hydrology (IMH). The primary goals of the project were to develop detailed wind resource maps for all regions of Mongolia for a comprehensive wind resource atlas, and to establish a wind-monitoring program to identify prospective sites for wind energy projects and help validate some of the wind resource estimates.
Biomass resource assessments indicate the availability of biomass for energy production. This handbook provides best practices for determination of biomass resource potentials and gives guidance for transparent presentation of results. Methods are provided for forest biomass, energy crops, agricultural residues and organic waste. For each biomass type, a distinction is made between statistical methods, spatially explicit methods, cost-supply methods and more advanced modelling methods. Furthermore, the handbook provides a detailed overview of sustainability aspects that can be implemented in future biomass resource assessments. The Biomass Resource Assessment Handbook is a product of the European 'Biomass Energy Europe' project, in which 16 renowned universities, institutes and companies worked on harmonisation of biomass resource assessments. The project has been supported by the European Commission under the 7th Framework Programme.
In the present study the energy potential of wind for the Eastern Province of Saudi Arabia is investigated. A suitable Weibull distribution is generated based on the data obtained for a duration of one complete year at a costal location in northeastern Saudi Arabia. Comparison of this model is made with the Rayleigh distribution of wind power densities. Two horizontal-axis type of wind energy conversion systems which operate at fixed rpm are considered and a model of quadratic power output function is used. It is found that the error in using the Rayleigh approximation will be less than 10% of the full rated power density level.
Weibull parameters of the wind speed distribution function were computed for 49 weather stations in Palestine. Wind potentials in kWh/m2 yr were calculated at the above stations, then contours of wind potential were drawn. Electricity from the wind can be generated, in some locations in the West Bank, at a cost of 0.07 $/kWh.
Wind and wind energy has always played an important role in the historical and economical development of Asia Minor and the geographical area covered by the Republic of Turkey today. The ancient city of Troia probably became rich with harbor fees from commercial vessels, which could not sail up the Dardanelles because of strong north-easterly winds and swift currents. As early as 1389 AC wind mills were already dominant landmarks and found their way even into naval maps. In 1940's wind mills ground corn, pumped water to fields and even powered first radio sets at the Anatolian country side. Like elsewhere, with the onset of oil era and construction of large hydroelectric and fossil fuel power plants this renewable energy source was forgotten in Turkey until recently. Today there is a serious intention on part of Turkish authorities to promote wind energy. The Ministry of Energy and Natural Resources approved the first B.O.T, wind park with 12 x 600 kW turbines in December 1997 and the contract text was initialled on April 3, 1998. By the time we present this paper this wind park should be in operation along with the first Autoproducer wind park with 3 x 500 kW turbines, which was connected to the grid on February 20, 1998. Efforts to include wind energy also in the B.O.O. Law are also continuing. We at Interwind estimate the usable wind energy potential in Turkey, at around 8'000 MW. However, how much of this potential can be utilized in the near future will depend on three factors; 1) Definition of the specific place of renewable energy sources in the overall energy politics of Turkey, 2) Reinforcement of infrastructure at high wind locations as a matter of priority, 3) Revision of legal frame work for independent power producers to address the realities of the present and demands of the future.
Wind has been proven as a cost effective and reliable energy source. Technological advancements over the last five years have placed wind energy in a firm position to compete with conventional power generation technologies. Saudi Arabia has a vast uninhabited land area as well as a long coastline, free from man made obstacles, presenting a possible wind resource. A research program is under way in the Energy Research Institute of the King Abdulaziz City for Science and Technology (ERI-KACST) with the aim of studying the potential of wind energy in Saudi Arabia. This paper presents a full description of the equipment, instruments, site specifications and other technical needs for the wind assessment project in Saudi Arabia.
Thirteen years of wind data from Bozcaada Meteo-station have been used to evaluate the potential of wind power on Bozcaada Island, in the North-eastern part of the Aegean Sea. Investigations show that Bozcaada has a considerable wind potential (average wind speed M = 6.4 ms−1 and a mean energy density E = 324 W/m−2 at the location of the meteo-station, at 10 m above ground level which could cover its yearly electricity demand by utilizing only one 250 kW wind turbine. The wind atlas analysis and application program, WAsP, has been used to evaluate the wind atlas statistics and energy densities of Bozcaada. The yearly power production of the 250 kW wind turbine, assumed to be installed has been calculated. Then an environmental and techno-economic analysis of wind power has been carried out.
New and renewable sources of energy can make an increasing contribution to the energy supply mix of developing countries in view of favourable renewable energy resource endowments, limitations and uncertainties of fossil fuel supplies, adverse balance of payments, and the increasing pressure on the environment from conventional energy generation. Among the renewable energy technologies, the generation of mechanical and electric power by wind machines has emerged as an economically viable and cost effective option. Therefore the Sudanese government has begun to pay more attention to the use of wind energy in rural areas in particular as a cost-effective solution to assist in water pumping and irrigation.
A recent increase in interest and development of wind energy in the Midwestern United States has focused the need for updating wind resource maps of this area. The wind resource assessment group at the National Renewable Energy Lab., a U.S. Department of Energy (DOE) laboratory, has produced updated high-resolution (1-km) wind resource maps for several states in this region. This abstract describes the computerized tools and methodology used by NREL to create the higher resolution maps.
The National Renewable Energy Laboratory (NREL) uses Geographic Information Systems (GIS) to further the development of wind energy resources in support of the U.S. Department of Energy (DOE) Wind Energy Program and its Wind Powering America Initiative. Some of the elements of NREL's GIS data used in wind energy activities include wind measurement sites, transmission lines, federal facility information, and modeled wind resources. More complex GIS analyses can define relationships among the mapped wind energy resources, potential energy load characterization, and utility integration problems. A GIS is an outstanding tool for wind energy activities because data can be readily updated and the results of the GIS analyses can be expressed as charts, tables, and maps. These outputs are in digital formats that allow the results of GIS analyses to be quickly and efficiently distributed to the wind energy industry.
The objective of this program was to investigate the feasibility of employing wind power as a possible energy source to the New Hampshire power grid. Wind data was obtained from the New Hampshire State Forestry Service, the State Climatologist as well as other miscellaneous sources. Data on power generation and the power grid system was received from the Public Service Company of New Hampshire. Using this information as a data base, siting studies were made which indicated that there was a potential for a wind energy system in New Hampshire. Costs of fossil fuel generated power were compared to estimated wind generated production costs of electric energy fed into the Public Service Company of New Hampshire lines for various potential WECS sites. Based on the data and analysis provided in this study, it appears that WECS can be usefully developed in New Hampshire which would result in significant savings in fuel oil consumption.
Wind power meteorology has evolved as an applied science firmly founded
on boundary layer meteorology but with strong links to climatology and
geography. It concerns itself with three main areas: siting of wind
turbines, regional wind resource assessment and short-term prediction of
the wind resource. The history, status and perspectives of wind power
meteorology are presented, with emphasis on physical considerations and
on its practical application. Following a global view of the wind
resource, the elements of boundary layer meteorology which are most
important for wind energy are reviewed: wind profiles and shear,
turbulence and gust, and extreme winds. Copyright
This paper presents a pre-feasibility study for a proposed demonstration wind farm of about 6 MW in Zwara, 125 km west of Tripoli. This study is based on previous work, which will be modified according to the latest developments in wind energy converter system sizes. It includes an economic evaluation for this project based on different assumptions for the financial parameters.RETSceen software was used for the economic evaluation of this demonstration project. Three different sizes of WECSs (0.6, 1 and 1.5 MW) were studied as candidate sizes to be proposed for this demonstration wind farm. The pre-feasibility study indicated that the project is economically feasible for the three cases.
The wind power potential was summarized using data from thirteen weather stations. The overall long term average wind speed for Oman is a moderate 3.67(s.d.=2.13)m/s yielding a potential power of 30.30 W. Wind speeds at four stations, Thumrait, Sur, Masirah and Marmul, are appreciably higher than the national average and hence these stations have a great potential for wind power utilization. More data needs to be collected for a better understanding of the wind power potential for Oman.
The paper presents a status of wind power in Denmark and on the technical and industrial achievements. The present total installed capacity is be the end of 1995 approx. 630 MW, and the contribution to the electric energy generation in Denmark is approx. 4%.This presentation is to a large extent based on Andersen 1995a and Andersen 1995b.
Wind speed has been measured in Patenga, Cox's Bazar, Kuakata, Moheshkhali, and Noakhali by the computerized anemometers. The wind computers have been installed at 20 meters height. According to this study annual average wind speeds in the coastal regions of Bangladesh are greater than 6.5 m/s at the height of 20 meters. It has been observed that during day times (8 a.m. to 7 p.m.) wind speeds are about 30 to 40% higher than the average values. The value of the power exponent α has been determined in the above sites and it is 0.139. So, at 40 meters height the annual average wind speed is about 7.15 m/s. So, wind speeds in the coastal regions of Bangladesh are suitable for both water pumping and electricity generation. Details are given in this paper with graphical and analytical representations.
Detailed wind investigations have begun near the Clutha River in Central Otago, New Zealand to look for topographically augmented sites suitable for windfarm development close to large existing and potential hydroelectric power stations on the River. The main problem for immediate economic development of the sites is the competition from the very low priced electricity usually available from the national grid, so only easy access sites with the highest available wind speeds are being studied. Of the 8 sites so far investigated, all appear to be suitable for further investigation. Support through an ECNZ Research Contract is gratefully acknowledged.
This paper presents wind energy development in China by the description of wind energy resources, development experiences, future development planning, barriers of large scale dissemination and the international cooperation in the further development.
This paper describes recent activities on wind energy in Japan. The national “Sunshine Project” conducted by the Ministry of International Trade and Industry, was reviewed in 1990 to map out a new energy strategy in the Age of Global Environment. As a result, a new 500kW WECS R&D project has started in FY1991 and the operation started in FY1996. A number of basic and applied studies have been undertaken at the NEDO, the MEL and many universities. Interests in utilization of wind energy have spread gradually among power company. From FY1991, the Tohoku Electric Power Company has operated a 2,875kW Windpark(5 units of 275kW machine and 5 units of 300kW machine) at Tappi, where the annual wind speed is as strong as 10m/s.Researches and demonstrations are also conducted by some other power companies. MHI has developed middle-sized commercial WTGs. More than 800 units were exported to the United States and UK. IHI also developed 300kW machines. Fuji Heavy Industry is developing new concept machine of small to medium size.
Wind, in South Africa, has been a source of energy for many years but at the same time it is taking as much time and effort to receive the recognition it deserves as anywhere else in the world. The wind resource is comparable to a number of areas in the world where wind is exploited as a grid connected source of electrical energy. Although the environmental impact of conventional sources of energy is not as wide spread as most of the industrial nations some areas should be looked at critically. Wind as a bulk generator of energy is tentatively being looked at with some demonstration projects being planned.
This paper describes how data from a variety of sources are merged to present new countrywide maps of the solar energy distribution over Ethiopia. The spatial coverage of stations with radiation data was found to be unsatisfactory for the purpose of a countrywide solar energy assessment exercise. Therefore, radiation had to be predicted from sunshine hours by employing empirical models. Using data from seven stations in Ethiopia, linear and quadratic correlation relationships between monthly mean daily solar radiation and sunshine hours per day have been developed. These regional models show a distinct improvement over previously employed countrywide models. To produce a national solar-energy distribution profile, a spatial extension of the radiation/sunshine relationships had to be carried out. To do this, the intercepts (a) and slopes (b) of each of the seven linear regression equations and another six from previous studies, completed in neighbouring Sudan, Kenya and Yemen, were used to interpolate the corresponding values to areas between them. Subsequent to these procedures, 142 stations providing only sunshine data were assigned their “appropriate” a and b values to estimate the amount of solar radiation received, which was then used to produce annual and monthly solar radiation distribution maps for Ethiopia. The results show that in all regions solar energy is an abundant resource.
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 5m/s to 10m/s and the average power density from 100W/m2 to 1000W/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 1817MW, that is to say, the exploitable wind energy is 15198GWh, which represents theoretically 11% of the total consumed energy in Morocco in 1994.
The flow in the atmospheric surface layer is summarized with emphasis on those properties which are of primary importance for the prediction of wind pressures on low-rise structures from wind tunnel simulation experiments.For neutral flow near the surface over flat, smooth and uniform (FSU) terrain, flow models derived from similarity analysis match the available observations quite well. However as the upwind terrain becomes increasingly perturbed with scattered obstacles such as buildings, trees etc. or with topographic features, the observed flow characteristics deviate increasingly from those associated with the FSU model, and parameters derived from mean wind profiles cannot be used to predict turbulence intensities. Over complex terrain the large-scale horizontal velocity fluctuations bear the characteristics of the upwind terrain and their intensities can only be predicted with the use of a “regional” roughness length. Based on the variation and scale of the upwind terrain roughness and topography, four aerodynamic terrain categories each with its own flow parameters are recognized. A general model for the velocity spectra has been presented, for which the coefficients and exponents have been adapted to each of the four terrain categories. Predicted spectral shapes are compared with existing models and existing observations.
The paper attempts the assessment of a part of design and erection activities in wind energy field, in western Romania, from Electromontaj S.A. one new 100 % private company.So I shall refer to achievements of construction and erection:First the 3 MW demonstrative wind farm in Banat Mountain, and second the programmes for erection of experimental small wind turbines for operation in isolated settlements, in the power range 0,5–10 KW, and erection PV/Wind Turbines/Battery Systems, in small villages where are many lonely houses, who haven't electricity, for first time in our country.
The recent publication of the Digital Elevation Model (DEM) database by the US Geological Survey (USGS) has provided a unique opportunity for the development of cost-effective wind energy prospecting technology. This database contains terrain elevation values on a Latitude-Longitude grid with a resolution of 3 arc-seconds (about 90 m) for the contiguous United States, Hawaii, and Puerto Rico. This database has been coupled with software that will produce shaded-relief maps on a laser printer in a format compatible with the state wind power maps in the US wind energy atlas. By providing a much higher resolution of the terrain features than was possible when the US atlas was prepared, these maps can be useful in general wind prospecting activities. As highly resolved as the 90-m DEM data seem to be when compared to the atlas grid, they still appear to be too coarse to resolve terrain features in the detail required for local wind flow characterization and wind plant layout. Gridded terrain data at about 10-m resolution are available from the USGS for some areas of the United States. In areas where these data are unavailable, they may be generated by digitizing and gridding the contours from a 1:24,000-scale USGS map over the area of interest. Comparisons of terrain profiles from cross sections of the 10-m and 90-m data provide an indication of the effect of resolution on the reliability of terrain feature representation. Oblique views of the terrain in shaded-relief format provide a dramatic enhancement of the shape and relative position of features of interest.
This report contains the results of a wind resource analysis and mapping study for the Philippine archipelago. The study's objective was to identify potential wind resource areas and quantify the value of those resources within those areas. The wind resource maps and other wind resource characteristic information will be used to identify prospective areas for wind-energy applications.
This report, which focuses on the meteorological aspects of siting large wind turbines (turbines with a rated output exceeding 100 kW), has four main goals. The first is to outline the elements of a siting strategy that will identify the most favorable wind energy sites in a region and that will provide sufficient wind data to make responsible economic evaluations of the site wind resource possible. The second is to critique and summarize siting techniques that were studied in the Department of Energy (DOE) Wind Energy Program. The third goal is to educate utility technical personnel, engineering consultants, and meteorological consultants (who may have not yet undertaken wind energy consulting) on meteorological phenomena relevant to wind turbine siting in order to enhance dialogues between these groups. The fourth goal is to minimize the chances of failure of early siting programs due to insufficient understanding of wind behavior.
The Wind Energy Resource Atlas of the Dominican Republic identifies the wind characteristics and the distribution of the wind resource in this country. This major project is the first of its kind undertaken for the Dominican Republic. The information contained in the atlas is necessary to facilitate the use of wind energy technologies, both for utility-scale power generation and off-grid wind energy applications. A computerized wind mapping system developed by NREL generated detailed wind resource maps for the entire country. This technique uses Geographic Information Systems (GIS) to produce high-resolution (1-square kilometer) annual average wind resource maps.
Guidelines for siting wind energy conversion systems (WECS) relative to
small-scale terrain features are presented to assess the influence of
small or microscale terrain features on a proposed wind turbine site.
Three categories of terrain were considered: (1) protrusions,
topographical features that protrude well above the general level of
their neighboring terrain; (2) depressions, valleys, canyons, or passes;
and (3) complex terrain, so rugged or irregular that no well defined
protrusion or depression can be easily distinguished. The optimum site
on a protrusion is always at the highest point. The smoother the peak of
the protrusion and the more gentle the slopes on all sides the more
optimum the site, providing the geometry and orientation of the
depression are such that full advantage can be taken of existing strong
valley winds or outflow. Where the terrain is very complex and tortuous,
the highest point of the topography will be the optimum site.
This handbook was written to serve as a siting guide for individuals wishing to install small wind energy conversion systems (WECS); that is, machines having a rated capacity of less than 100 kilowatts. It incorporates half a century of siting experience gained by WECS owners and manufacturers, as well as recently developed siting techniques. The user needs no technical background in meteorology or engineering to understand and apply the siting principles discussed; he needs only a knowledge of basic arithmetic and the ability to understand simple graphs and tables. By properly using the siting techniques, an owner can select a site that will yield the most power at the least installation cost, the least maintenance cost, and the least risk of damage or accidental injury.
This atlas estimates wind energy resource for the United States and its
territories, and indicates general areas where a high wind resource may
exist. This information is valuable to wind energy developers and
potential wind energy users because it allows them to choose a general
area of estimated high wind resource for more detailed examination.
Utility oriented guidelines are described for identifying viable sites
for wind turbines. Topics and procedures are also discussed that are
important in carrying out a wind turbine siting program. These topics
include: a description of the Department of Energy wind resource
atlases; procedures for predicting wind turbine performance at potential
sites; methods for analyzing wind turbine economics; procedures for
estimating installation and maintenance costs; methods for analyzing the
distribution of wind resources over an area; and instrumentation for
documenting wind behavior at potential sites. The procedure described is
applicable to small and large utilities. Although the procedure was
developed as a site selection tool, it can also be used by a utility who
wishes to estimate the potential for wind turbine penetration into its
future generation mix.
Wind has been proven as a cost effective and reliable energy source. Technological advancements over the last five years have placed wind energy in a firm position to compete with conventional power generation technologies. Saudi Arabia has a vast uninhabited land area with a long coastline, free from man made obstacles, presenting a possible wind resource. A research program is under way to study the potential of wind energy in Saudi Arabia. This paper presents analysis of wind data from five selected sites as well as preliminary evaluation of the potential of wind energy.
Under its wind energy research and development program, the U.S. Department of Energy (DOE) works as a partner with industry to improve understanding of wind system technology and to develop and deploy advanced wind turbines in multi-regional markets. Installed capacity in the U.S. reached 1720 MW by the end of 1995. This figure however does not include some capacity that was retired or taken off line. Growth of about 140 MW during 1995, is attributed to improved and lower cost turbines and was stimulated in part by the availability of energy tax credits and production and financial incentives. In addition, there are nearly 500 MW of firm contracts for new domestic wind plants. Recently, there has been substantial growth outside the U.S. Europe went from 1671 MW in 1994 to 2478 MW in 1995 and the rest of the world went from 192 MW in 1994 to 642 MW in 1995. Commercial projects are currently producing electricity in the $0.05 to $0.07/kWh range operating at moderate (5.8 m/s average) wind sites.The U.S. DOE Wind Energy Systems Program is continuing broad based research and technology development, focusing on advanced wind turbine development. Contracts have been placed with industry for next generation design studies, innovative subsystems applied research, and value engineering to improve existing turbines. Some of these turbines are now being deployed in utility verification projects. Over the past year, the U.S. opened its National Wind Technology Center, located near Golden, Colorado. The center will include a new user facility to serve as a wind turbine blade and system testing and research center for industry.
In case of RC members strengthened by means of externally bonded reinforcement, a premature failure can be detected in addition to the conventional modes of failure observed in RC unstrengthened beams. The premature failure occurs mainly due to both shear and normal stresses induced in either the external reinforcement–concrete interface or at the level of steel reinforcement. This research is part of a complete programme aiming to set up design formulae to predict the strength of CFRP strengthened beams, particularly when premature failure through laminates-end shear or concrete cover delamination occurs. Series of RC beams were strengthened with carbon-fiber-reinforced plastic (CFRP) laminates and tested to estimate the extent of the applicability of the formulae proposed by the authors, as well as to study the influence of the layout of the external reinforcement in terms of unsheeted length (the distance between CFRP laminates-end and the nearer support) and cross-sectional area, on the behaviour of strengthened beams. The predictions using the proposed formulae are compared with the obtained experimental results, as well as with the calculated design limit states. The interfacial shear stress and the maximum deflection corresponding to the predicted values at maximum and service loads are also studied.
The Caribbean has the potential for a significant increase in windpowered electricity production. A number of wind farm projects are being implemented, making wind potentially the fastest growing renewable energy technology in the region over the next two decades. Wind promises to provide more than 10 per cent of the electricity in many Caribbean countries by the year 2020.
Wind data for 70 stations in Sudan have been analysed. Yearly wind speeds map was drawn. Results suggest that wind power would be more profitably used for local and small-scale applications.
This paper presents a study for utilization of wind energy in Egypt at coastal and some remote desert areas. The available wind energy data at the north coast, the Red Sea coast and east of Oweinat were collected, analyzed and are presented in a form useful for wind energy study. The investigation aimed at evaluating average wind speed for the most promising sites. Moreover, the possible amount of captured energy for each site is determined. Average and r.m.s. values of power are calculated in order to determine the power form factor. These parameters at any site are essential for choosing the appropriate wind turbine. The assessment reveals that these remote sites offer sufficient wind energy for economic utilization and represent a good example for utilizing wind energy to supply a part of the energy requirements to those communities. The design of a wind chart is presented in detail. The study confirms that the Capacitor Self-Excited Induction Generator, Reluctance Generator and Permanent-Magnet Generator emerged as suitable candidates for utilizing wind energy in isolated and remote areas.
Wind characteristics and wind turbine characteristics in Taiwan have been thoughtfully analyzed based on a long-term measured data source (1961–1999) of hourly mean wind speed at 25 meteorological stations across Taiwan. A two-stage procedure for estimating wind resource is proposed. The yearly wind speed distribution and wind power density for the entire Taiwan is firstly evaluated to provide annually spatial mean information of wind energy potential. A mathematical formulation using a two-parameter Weibull wind speed distribution is further established to estimate the wind energy generated by an ideal turbine and the monthly actual wind energy generated by a wind turbine operated at cubic relation of power between cut-in and rated wind speed and constant power between rated and cut-out wind speed. Three types of wind turbine characteristics (the availability factor, the capacity factor and the wind turbine efficiency) are emphasized. The monthly wind characteristics and monthly wind turbine characteristics for four meteorological stations with high winds are investigated and compared with each other as well. The results show the general availability of wind energy potential across Taiwan.