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The aim of this work is to compare the wind data extrapolated by 1/7 th wind power law and site-specific wind power law for wind power potential estimation at Shahbandar. Both the Wind shear exponents (WSE) and local air density values were calculated using measured wind data at 10 and 30 m heights and they were found minimum in summer and maximum...
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... However, wind power law is oversimplified in previous studies by using a constant 1/7 value worldwide as the wind power law exponent [9][10][11][12][13]. The α value of 1/7 and its characteristics are debated especially in recent studies [14][15][16][17]. In realistic circumstances, the observed power law exponent α exhibits spatiotemporal variation regarding the conditions including atmospheric stability and surface roughness [18][19][20]. ...
... The clear differences and opposite monthly changes in α values between land and ocean are in agreement with previous studies [26]. In our study, α values on land are smaller in summer and larger in winter, this feature also appears in many studies based on regional measurements [14,21,22,26,27,41]. In some studies, the diurnal variation of α values is characterized by being smaller during the day and larger at night. ...
Assess the spatiotemporal variation of the power law exponent (α) in global wind energy assessments. • The power law exponent α values vary with geography, seasons, diurnal cycles, latitudes, land and ocean. • The power law is generally applicable and has important implications for wind energy resource assessments and turbine design. A R T I C L E I N F O Keywords: Power law exponent Multiple heights Spatiotemporal variation Wind energy A B S T R A C T The power law, a common method in wind energy assessments, often assumes a global power law exponent (α) of 1/7, potentially leading to inaccuracies in estimating wind conditions and energy potential. This study uses high-frequency measurements from eight wind towers to assess the power law's reliability and demonstrates its general applicability, except in complex topography. The α value is found to differ significantly from 1/7 in validation sites, yet it can be reliably used in ERA5 data based on regional verification. To evaluate the global spatiotemporal variation of α, we analyze the hourly α from 1980 to 2022 using ERA5 wind speed data at 10 m and 100 m. Our findings reveal varying α value with time and geography, with particular disparities between land and ocean. Additionally, we observe changes related to diurnal cycles, seasons, and latitudes. This analysis of α value carries significant implications for a global-scale wind energy resource assessment, site selection, and turbine design.
... The renewables being considered include wind, solar, biomass, biogas and geothermal biofuel (Ajayi et al., 2013;Patidar et al., 2022). Nonetheless, despite all efforts, fossil fuels still lead globally harnessed energy, most notably coal, natural gas and oil (Adem C xakmakc xı and Hu¨ner, 2022;Sumair et al., 2021). ...
... Wind is one of the most promising, important, and viable sources of RE sources (El Khchine et al., 2019;Okundamiya et al., 2014;Sumair et al., 2021), due to its clean nature, abundance, and potent price (Akpinar, 2006;Okeniyi et al., 2015;Wang and Liu, 2021). Wind, formed by atmospheric transformation, is one of the most popular resources (Du¨zcan and Kara, 2021;Juan et al., 2022;Wu et al., 2013). ...
... A closer look at the global installed wind capacity depicts an increase of 86 GW between the end of 2010 and 2012 (Sumair et al., 2021). A gain of 150 and 131 GW at the end of 2015 and 2018 respectively, and by 2019, with about 60,400 MW new installations, global wind capacity surpassed 651 GW (Potic´et al., 2021;Sumair et al., 2021;Vallejo-Dı´az et al., 2022) as illustrated in Figure 1. ...
This review paper evaluates the current status of the Nigeria wind energy sector to identify the available Wind Energy Potential, Installed Wind Energy Capacity and Renewable Energy Policies in a bid to provide accurate information to aid the exploration and exploitation of wind energy across Nigeria. Consequently, the huge expanse between the wind energy Potential across Cities in Nigeria, the poor numbers of installed wind capacity and Nigeria's Renewable Energy policies show low interest in Wind Energy in comparison to other RE sources. All this calls for further investment in the Nigerian wind energy sector
... In Refs. [28,29], the wind speed power law was found to be sufficiently accurate As seen in Figure 2, the empty space between the PV module rows was determined so that when the altitude angle of the Sun was 20 • , the PV modules would not shade each other. Therefore, the length of the empty space was calculated to be 1916 mm. ...
... In Refs. [28,29], the wind speed power law was found to be sufficiently accurate at extrapolating wind speeds to given heights when using a suitable value for the shear exponent α. The power law was applied as where v 2 is the extrapolated wind speed at height h 2 , and v 1 is the measured wind speed at height h 1 . ...
As the share of highly variable photovoltaic (PV) and wind power production increases, there is a growing need to smooth their fast power fluctuations. Some countries have set power ramp rate (RR) limits that the output powers of power plants may not exceed. In this study, the effects of RR limit on the sizing of energy storage systems (ESS) for PV, wind, and PV–wind power plants are examined. These effects have been studied prior for PV power plants. However, for the wind and PV–wind power plants, the effects of the RR limit are studied comprehensively for the first time. In addition, the effects of the size of the power plant are considered. The study is based on climatic measurements carried out with a sampling frequency of 10 Hz for a period of 153 days. The modeling of the PV and wind powers and the simulation of the RR-based control algorithm of the ESS were completed using MATLAB. The results show that as the applied RR limit increased from 1%/min to 20%/min, the required relative energy capacities of the ESSs of the PV, wind, and PV–wind power plants decreased roughly 88%, 89%, and 89%, respectively. The required relative power capacities of the ESSs of the PV, wind, and PV–wind power plants decreased roughly 15%, 12%, and 20%, respectively. The utilization of the ESSs was found to decrease as the applied RR limit increased and as the size of the power plant grew.
... 18 Thus, it is mandatory to look for the Renewable Energy Sources (RES), which are growing at a fast pace throughout the world to replace the current mix. 14,[19][20][21][22][23][24] Experts argue that the alternative sources of producing energy are of indigenous nature and environmentally friendly. The review of renewable potential predicts a success for RE in Pakistan. ...
Pakistan is fighting a long‐standing energy crisis with an unbalanced, fossil‐fuel dominated energy mix mired with climatic catastrophes. World Wide Fund for Nature (WWF), in its fight against climate change, has proposed a global energy model that illustrates a shift to renewable energy completely by the year 2050. In this study, we have scaled down that energy model for Pakistan to demonstrate country level implementation of WWF's vision. Scenario‐based energy model of Pakistan is developed in this research using LEAP Software. Four scenarios namely, Business‐As‐Usual (BAU), Alternative and Renewable Energy (ARE), Green Energy (GE) and Advanced Sustainable Energy (ASE) are developed. The BAU scenario is based on government's existing policies and plans, and ASE scenario shows the crux of WWF's Global vision on Pakistan's scale. ARE and GE are intermediate scenarios reflecting a transition from BAU to ASE. Simulation results demonstrated the demand in ASE is halved as compared to BAU and its energy mix is homogeneous and completely renewable. In conclusion, ASE gave country‐level insights into WWF's vision towards the ways to contend climate change. This work inspires country‐scale modeling of WWF's vision for other countries as well.
... The optimum tilt angle for three pairs of locations having comparable latitudes were compared and it was found that the sites having does not pose environment to risk. [1][2][3][4][5] In the wake of global inclination towards cutting down the conventional energy sources (fossil fuels etc.) because of environmental concerns, green energy sources are seeking huge attention these days. [6][7][8][9][10] Among various renewable energy sources and technologies, solar energy is one of the attractive options which is an unlimited source of energy. ...
Carrying out the dual objectives of computing the optimized tilt angles for multiple locations in Pakistan along with recommending a generalized approach for the estimation of optimum tilt angle for any location in country, this study was conducted. Python code was developed for the optimization purpose of daily, monthly, seasonally, biannually and annual solar tilt angle. Detailed analysis was presented for one location (Karachi) and a comparative analysis of optimum tilt angle conditions has been conducted for all investigated sites. Daily optimum tilt angles were found to vary from −12.0° to 55.5°. Similarly, monthly optimized tilt angles were found to vary from −11.5° (in June) to 55.0° (in December). Furthermore, seasonal tilt angles were found as 46.0 °, 2.0 °, 0.5 ° and 45.0 ° in winter, spring, summer and autumn respectively. Finally, annual optimum tilt angle (fixed throughout the year) was found as 25.5° (closer to the latitude value of Karachi). It has been found that daily adjustment of tilt angle causes a gain of 6.85% in annual energy yields when compared with fixed angle throughout the year. Similarly, energy gains were found as 0.15%, 1.24% and 6.83%, when tilt angle was adjusted daily as compared to monthly, seasonal and biannual adjustment cases respectively. The optimum tilt angle for three pairs of locations having comparable latitudes were compared and it was found that the sites having comparable latitudes do not have any marked difference in their optimum tilt angle values.
... Furthermore, a 50 KW horizontal axis downwind based wind turbine with a swept area of 290 square meters has been chosen for the purpose of wind energy system design [33]. This smaller wind turbine has a hub height of 25 meters and can accommodate wind speeds of around 4.5 m/s at that location [34]. ...
... The empirical power-law vertical profile is used to adjust the wind velocities of reanalyses data to the required hub heights of the wind turbines according to Eq. (1) (Touma, 1977;Sumair et al., 2021). This expression does not account for the influence of atmospheric stability, however due to the lack of specific in situ measurements, it is assumed the power-law expression provides a simple and practical approach to adjust the wind speeds to the required hub height from the 100 m reference. ...
Mexico is an attractive candidate for offshore wind energy development due to its geographical location with extensive coasts in the Pacific Ocean and Mexico's Gulf. Although potential offshore wind areas have been geographically assessed, an evaluation of the seasonal variations of the capacity factors has not been considered for the feasibility of the locations. This research identifies potential zones for offshore wind development in the Gulf of Mexico, implementing geographical restrictions such as the Economic Exclusive Zone, distance from the coast, protected areas, bathymetry, and capacity factor seasonality. Wind speeds were obtained from 39 years of reanalyses historical data and two reference wind turbines of 5 and 10 MW were included in the analysis. Three potential areas were identified from the results: the northeast Tamaulipas, the western Campeche, and the northern Yucatan. Monthly mean capacity factors above 45% were estimated from October to June, with the maximum values near 60% between March and April. Conversely, minimum values were observed from July to September but consistently higher than 30%. The analyzed zones show suitable technical conditions for offshore wind development. Further analysis is needed to validate the wind speed conditions, in addition to the evaluation of economic factors, the study of extreme weather conditions like tropical cyclones as well as characteristics in the intertropical region.
... For these purposes, an appropriate wind model is required to accurately analyze the wind data measured at the site [6] because the wind energy is much related to the site and geographic conditions [7]. Another method to extrapolate wind data precisely is by using a site-specific wind power law [8]. ...
span lang="EN-CA">Estimating wind speed characteristics plays an essential role in designing a wind power plant at a selected location. In this study, the Weibull, gamma, and exponential distribution models were proposed to estimate and analyze the wind speed parameters and distribution functions. Real measured data were collected from Medan City, Indonesia. The scale and shape factors of wind distribution for three years data were calculated. The observed cumulative probability of the three models was compared to predicted wind characteristics. The probability density function (PDF) and the cumulative density function (CDF) of wind speed were also analyzed. The results showed that the Weibull model was the best model to determine PDF, while the exponential model was the best model to determine CDF for the Medan City wind site.</span
In Egypt, the wind market increases quickly to make it one of the top countries in the Middle East. This study discusses the viability of wind resources and the economic assessment for four locations in Egypt: Ras El-Hekma, Farafra, Nuweiba, and Aswan through two stages. In the first stage, the optimal hub height for some wind turbines has been calculated by using Equilibrium Optimizer (EO) algorithm to achieve maximum wind energy with overall minimum cost. The second stage, the economic assessment has been evaluated by using such turbines to calculate the cost of energy (COE) compared to the global and Egyptian production costs of wind energy. Developed MATLAB programs are applied for statistical analysis of wind data. The results have shown that Ras El-Hekma’s average wind speed is higher than other sites and its wind energy potential is the best. Moreover, the economic assessment for selected locations turns out that Ras El-Hekma by using EWT-DW61/22 turbine has the lowest COE.
In order to meet the load demand of power system, BP based on genetic algorithm is applied to the typical daily load forecasting in summer. The demand change of summer load is analysed. Simulation results show the accuracy of the algorithm. In terms of power supply, the reserves of fossil energy are drying up. According to the prediction of authoritative organizations, the world's coal can be mined for 216 years. As a renewable energy, wind power has no carbon emissions compared with traditional fossil energy. At present, it is generally believed that wind energy and solar energy are green power in the full sense, and they are inexhaustible clean power. The model of wind power solar hydrogen hybrid energy system is established. The control strategy of battery power compensation for delayed power of hydrogen production is adopted, and different operation modes are divided. The simulation results show that the system considering the control strategy can well meet the load demand. Battery energy storage system is difficult to respond to short-term peak power fluctuations. Super capacitor is used to suppress it. This paper studies the battery supercapacitor complementary energy storage system and its control strategy. When the line impedance of each generation unit in power grid is not equal, its output reactive power will be affected by the line impedance and distributed unevenly. A droop coefficient selection method of reactive power sharing is proposed. Energy storage device is needed to balance power and maintain DC voltage stability in the DC side of microgrid. Therefore, a new droop control strategy is proposed. By detecting the DC voltage, dynamically translating the droop characteristic curve, adjusting the output power, maintaining the DC voltage in a reasonable range, reducing the capacity of the DC side energy storage device. Photovoltaic grid connected inverter chooses the new droop control strategy.
