Averaged Wind Data Research Articles

Development of a novel method for the correction of the nacelle wind speed in stall-controlled wind turbines

Accurate estimation of the oncoming wind is key to ensure an accurate control of any wind turbine. The wind speed is commonly measured with an anemometer located on the nacelle; hence, the measurement is influenced by the rotor and the nacelle itself and needs to be corrected so as not to incur inaccurate energy yield assessments. This study introduces an innovative method for correcting the nacelle wind speed in stall-controlled wind turbines. The development of the method has benefitted from the unique possibility of exploiting two datasets containing 10-minute averaged wind data from two identical EUNICE EW16 wind turbines and a meteorological mast located at the same site. The innovative method is systematically compared with the Nacelle Transfer Function outlined in the IEC 61400-12-2, serving as a benchmark for evaluation. The high accuracy and simplicity of the proposed method make it particularly suitable for the optimization of wind turbine performance in industrial applications. Moreover, an accurate estimation of the incoming wind speed can enable innovative control techniques, such as those based on Tip-Speed-Ratio (TSR) tracking. This is addressed in the study through simulations by comparing a TSR-Tracking strategy with the most common k-ω2 strategy. The study demonstrated that the TSR-Tracking strategy could be adopted in stall-controlled wind turbines if an accurate estimation of the free-stream wind speed is available.

Wind Variability and its Impact on IOD and MJO Phenomena in Western Waters


 
 
 
 
 
 This study investigates the interplay between wind variability and the Indian Ocean Dipole (IOD) and Madden-Julian Oscillation (MJO) phenomena in the western waters of Sumatra during the period 1982-2021. Utilizing monthly average wind data from satellite images, the research employs a comprehensive approach involving GrADS, Microsoft Excel, Surfer, Matlab, and Panoply software for data processing. The analysis reveals distinct wind patterns and varying IOD and MJO phases, with notable instances such as a positive IOD in October 1982 and a negative IOD in March 1983, coupled with strong MJO activity in February 1982 and weak activity in October 1983. This research underscores the significant influence of wind conditions on the dynamics of IOD and MJO phenomena in the studied region, contributing to a deeper understanding of ocean-atmosphere interactions.
 Highlight:
 
 
 
 
 
 
 
 
 
 
 
 Temporal Analysis: This study examines wind variability's interplay with IOD and MJO phenomena over three decades, revealing distinct patterns and phases in the western waters of Sumatra.
 Comprehensive Approach: Utilizing advanced software tools, the research processes satellite-derived wind data, shedding light on the complex dynamics of ocean-atmosphere interactions.
 Phenomena Dynamics: Notable occurrences, including positive and negative IOD events and varying MJO strengths, emphasize the profound impact of wind conditions on shaping the behavior of these critical climate phenomena, contributing to enhanced understanding and prediction.
 
 
 
 
 
 
 
 
 Keyword: Wind Variability, Indian Ocean Dipole (IOD), Madden-Julian Oscillation (MJO), Ocean-Atmosphere Interactions, Western Sumatra
 
 
 
 
 
 
 
 

ANALISIS TINGGI GELOMBANG AKIBAT WIND SETUP DI PANTAI SAWANGAN DENGAN METODE HINDCASTING

Sawangan Beach is located directly facing the Indian Ocean, the high waves and the generation by the wind which produce great energy that hits Sawangan Beach. The coastline was a setback when, around 2010, the access from Sawangan Beach to Pura Geger had turned into rock because the sand on the beach was increasingly eroding. The increasingly steep coastal contours can interfere with fishing activities and the existence of existing groin buildings that are hit by high waves causes the position of the protective stones to not function properly. Therefore it is considered necessary to know the wave height and period at Sawangan Beach. This wave height calculation can later be used in planning appropriate coastal protection structures on the beach. Calculation of wave height in this study focuses on wave generation due to wind, which is called a wind setup using the hindcasting method. Data In determining wave height, wind data is needed. Monthly maximum average wind data from BMKG sources includes 8 directions and wind speeds. The dominant wind is cdaric eastward c, namely c40.83%. Forecasting wave height (hindcasting) from the calculation of the wind stress factor and effective fetch, the value of the wave height (H) is 2.75 meters with a wave period (T) of 10 seconds

Investigation of Wind Data Resolution for Small Wind Turbine Performance Study


 Small wind turbine sites, in general, use a 0.5Hz sampling interval and a 10-minute averaging interval for a feasibility study or turbine testing. Studies have established that the calculated performance variation of small wind turbines when averaging at large time intervals. The performance variation is larger for sites with high wind variability. However, these studies are often based on low sampling frequency and high averaging intervals. 
 
 
 In the present study, wind speed data has been measured at a high sampling frequency of 20Hz with an ultrasonic sensor. A dynamic model of a 50W Rutland wind turbine is used to analyse the simulated performance using wind speed data at a range of sampling intervals and some averaging intervals. The wind turbine and the anemometer are installed in a residential area of high wind variability. 
 
 
 The energy is calculated and compared directly using the wind turbine model and using the IEC recommended method of bins. The direct method results show that the rise in instantaneous sampling intervals up to 20 seconds has an insignificant effect on the energy output. Whereas, for 2-seconds sampled wind data averaged over 10-minutes, energy overestimates of 19% is observed. However, where only 10-minute interval averaged wind data are available, there is a significant underestimate in energy by 45%. The energy calculated using the method of bins overestimates the energy by 19% for high resolution wind data and underestimates by 22% for 10-minute average data.

A statistical analysis of the distribution of convective windstorms and their radar characteristics in Hubei Province, China. Part 2

A statistical analysis of the distribution of convective windstorms and their radar characteristics in Hubei Province, China. Part 2

Extremely Slow (V sw < 300 km s−1) Solar Winds (ESSWs) at 1 au: Causes of Extreme Geomagnetic Quiet at Earth

A search for extremely slow (V sw < 300 km s−1) solar winds (ESSWs) at 1 au has been conducted using hourly average solar wind data from 1963 through 2021. 297 ESSW events were identified with an average duration of ∼2.0 ± 1.4 days. The lowest speed detected was 156 km s−1. Ten of the lowest-speed events were analyzed in detail. It was found that all 10 events were located at the ends of high-speed solar wind (HSSW) streams. The termination of the ESSWs was caused by high-density plasmas, either a corotating interaction region associated with the next HSSW stream or a heliospheric plasma sheet encounter. There was a greater occurrence of ESSW events in solar cycles 23 and 24 than in previous solar cycles. This phenomenon is associated with the much lower solar activity during these two cycles. The decrease in solar polar open magnetic fields was accompanied by an increase in low and midlatitude open magnetic fields. The ESSWs were accompanied by low interplanetary magnetic fields (4.4 ± 2.1 nT) and low negative interplanetary B z fields (−1.7 ± 1.5 nT), which led to extreme geomagnetic quiet: AE = 67 ± 78 nT and Dst = 2.2 ± 9.9 nT. We encourage magnetospheric researchers to use ESSW events to better understand the ground states of the magnetosphere and ionosphere.

Assessment of the cooling effect of the body and frostbite of open areas of the body in the Arctic condition

In conditions of arctic cold, individual protection means do not always provide sufficient efficiency when performing a number of works. The risk of body cooling (according to the index of cold wind — ICH) and frostbite of open areas of the body (according to the integral indicator of body cooling (IPCOO) and the equivalent temperature (EquT) was determined. EquT was calculated by Sayple and an improved formula. Evaluation was carried out according to meteorological data obtained at Cape Chelyuskin and Dikson Island. On Chelyuskin, according to IHV, year-round warming of the body is required. According to the average monthly indicators, the risk of cooling the body in winter clothes in April-May and October-November. In December-March, the HI values significantly exceed the critical values. Warming of the body on Dikson 10 months a year, risk zone — 8 months: cooling — autumn and March, April, critical cooling — winter months. According to EquT, the duration of the frostbite period for 1 min is longer — 5–6 months at temperatures from –27.0 ± 0.4 0 С to –45.4 ± 0.9 / –38.8 ± 0.5 0 С. On Dikson, the duration of the period of critical risk is 3 months, moderate — 7 months. According to EqT, there is a high risk of frostbite for 4–6 months at temperatures from –29.8 ± 0.3 0 С to –42.3 ± 0.7 / –34.3 ± 0.4 0 С. Taking into account the wind speed, which affects the thermal insulation properties of clothing, it should be assumed that, according to the average wind data, a high health hazard persists for 5–6 months on Chelyuskin, and 4–6 months on Dikson. insignificant danger persists all year round. The duration of the high hazard period is probably longer when assessing the effect of maximum wind and minimum temperature.

Measuring potential coastal sailing mobility with the loose-footed square sail

Measures of potential sailing mobility are essential for understanding the functioning of ancient maritime links. This requires measuring potential sailing mobility of coastal sailing runs, as well as direct passages in the open sea. Quantitative works attempting to measure potential sailing mobility have shortcomings related to the use of averaged wind data, thereby losing knowledge of wind variability; non-inclusion of the human factors impacting mobility; and not using methods of measuring coastal sailing. The method presented here was developed to measure potential sailing mobility of coastal sailing runs, based on using the patterns of hourly wind direction and speed variability – and specifically the coastal breeze cycle. The effects of wind variability on sailing mobility are extracted from a large dataset of data at high spatiotemporal resolution, by employing millions of sailing simulations which enable developing meaningful information from big data. This method has demonstrated its applicability to measuring coastal sailing mobility in several developmental case studies in the eastern Mediterranean, introducing realistic measures of mobility that include coefficients of mobility and of time spent waiting for favourable winds. Complementing a previously developed method to measure potential sailing mobility on direct open-sea passages, this new method can now provide a comprehensive toolkit for mapping potential sailing mobility. Such mapping is a valuable input to research on maritime networks and maritime-related developments.

Measuring Potential Coastal Sailing Mobility With the Loose-Footed Square Sail

Measures of potential sailing mobility are essential for understanding the functioning of ancient maritime links. This requires measuring potential sailing mobility of coastal sailing runs, as well as direct passages in the open sea. Quantitative works attempting to measure potential sailing mobility have shortcomings related to the use of averaged wind data, thereby losing knowledge of wind variability; non-inclusion of the human factors impacting mobility; and not using methods of measuring coastal sailing. The method presented here was developed to measure potential sailing mobility of coastal sailing runs, based on using the patterns of hourly wind direction and speed variability – and specifically the coastal breeze cycle. Wind variability is extracted from a large dataset of data at high spatiotemporal resolution, employing millions of simulations which enable developing meaningful information from big data. This method has demonstrated its applicability to measuring coastal sailing mobility in several developmental case studies in the eastern Mediterranean, introducing realistic measures of mobility that include coefficients of mobility and of time spent waiting for favourable winds. Complementing a previously developed method to measure potential sailing mobility on direct open-sea passages, this new method can now provide a comprehensive toolkit for mapping potential sailing mobility. Such mapping is a valuable input to research on maritime networks and maritime-related developments.

Wind climate of the Melbourne metropolitan area

This paper describes a probabilistic analysis of data recorded by the Bureau of Meteorology (BoM) for the wind climate of the Melbourne metropolitan area. It is based on 10-minute average wind data from four automatic weather stations (AWS) ‒ at Melbourne and Essendon airports, Fawkner Beacon in Port Phillip Bay, and Moorabbin Airport. Corrections to the data were made to adjust to standard terrain conditions and height. For the land stations, these were based on estimates of the surface roughness length at each site as a function of wind direction, making use of recorded gust factors. For the Fawkner Beacon, which is completely surrounded by open water, the surface roughness length is a function of mean wind speed, and the Charnock relationship was used in determining the corrections. For each station the terrain-corrected wind data were fitted with Weibull probability distributions, as an all-direction group and for sixteen direction sectors. Directional probabilities were also determined. The parameters of the all-direction Weibull distributions are very similar for all four stations, but there are differences in directional probabilities for some directions, with a geographic trend from north to south in the region being apparent. Some possible explanations based on the general topography are given.

Exploring Solar and Wind Energy as a Power Generation Source for Solving the Electricity Crisis in Libya

The current study is focused on the economic and financial assessments of solar and wind power potential for nine selected regions in Libya for the first time. As the existing meteorological data, including wind speed and global solar radiation, are extremely limited due to the civil war in the country, it was therefore decided to use the NASA (National Aeronautics and Space Administration) database as a source of meteorological information to assess the wind and solar potential. The results showed that the country has huge solar energy potential compared to wind energy potential. Additionally, it is found that Al Kufrah is a suitable region for the future installation of the Photovoltaic (PV) power plant due to high annual solar radiation. Based on the actual wind speed analysis, Benghazi and Dernah are the best regions for large-scale wind farm installation in the future taking into account existing meteorological data limitations. The values of the wind power density in all regions are considerable and small-scale wind turbines can be used to generate electricity based on NASA average monthly wind data for 37 years (1982–2019). Moreover, this work aimed to evaluate the wind/PV systems technical and economically through RETScreen Expert (Version 6.0, CanmetENERGY Varennes Research Centre of Natural Resources Canada, Varennes, Canada). Focusing on the power supply crisis in the country, the potential of electricity production by 5 kW grid-connected residential/household rooftop PV in all regions is proposed and presented. Additionally, this paper evaluated a techno-economic analysis of the 50MW wind/PV system in suitable places. The performance of a 5 kW and 50 MW PV solar system with three PV technologies, namely mono-crystalline silicon, poly-crystalline silicon, and thin-film (CdTe), was also analyzed. The results demonstrated that the development of the wind/PV system in the selected regions is both technically and economically feasible. The outcomes of this study can help decision-makers in designing and installing PV power plants as an alternative source for the future.

Optimal sizing design of an isolated stand-alone hybrid wind-hydrogen system for a zero-energy house

This study examines the feasibility and optimal sizing design of a stand-alone wind/hydrogen hybrid power system for a house in Catalca, Istanbul, Turkey. The considered house is a remote house with no connection to the power grid lines. The designed system guarantees uninterrupted, reliable continuous power to the house at any time. The site location of Catalca is very suitable for wind energy, and the considered hybrid wind/electrolyzer/fuel-cell power system is a good alternative for supplying the energy need of the house. If the reliability of the power supply is crucial, then optimal sizing of the components, wind turbine, electrolyzer, storage tank, and the fuel-cell stack is critical. In this study, a stand-alone hybrid power system with a wind turbine, electrolyzer, storage tank, and fuel-cell stack that can supply the house continuously is sized using 10-minute averaged wind data of the site and consumption data of the house. As a usual practice in the wind market, for stand-alone houses, usually wind turbines with rated powers equal to almost three times the average power consumption is used. Our analysis showed that when an uninterrupted continuous power supply is a necessity, wind turbines with rated powers of at least ten times the average consumption should be used. Moreover, our analysis showed that such a study that accounts for calculations of all system components in small timeframes is essential to ensure uninterrupted continuous power supply. And the results show that the system is capable of providing uninterrupted power to the house all-year long.

RANS simulations of neutral atmospheric boundary layer flow over complex terrain with comparisons to field measurements

AbstractMicro‐scale Reynolds‐averaged Navier‐Stokes (RANS) simulations of the neutral atmospheric boundary layer (ABL) over complex terrain and a comparison of the results with conditionally averaged met‐tower data are presented. A robust conditional sampling procedure for the meteorological tower (met‐tower) data to identify near‐neutral conditions based on a criterion for the turbulence intensity is developed. The conditionally averaged wind data on 14 met‐towers are used for the model validation. The ABL flow simulations are conducted over complex terrain which includes a prominent hill using the OpenFOAM‐based simulator for on/offshore wind farm applications (SOWFA) with the k−ϵ and the SST k−ω turbulence models. The discretization of the production term in the transport equation for the turbulent kinetic energy (TKE) is modified to greatly reduce the commonly observed nonphysical near surface TKE peak. The driving inflow is generated through an iterative approach using a precursor method to reproduce the measured wind statistics at the reference tower. Both of the RANS models are able to capture the flow behavior windward of the hill. The SST k−ω model predicts more intense flow separation than the k−ϵ model downstream of the steepest sections of the hill. The wind statistics predicted at the location of the met‐towers by both of the RANS models are fairly consistent. Overall, the comparisons of the direction, mean, and standard deviation of the wind between the simulations and the tower data show reasonable agreement except for the differences of the mean wind speeds at four met‐towers located closer to the main ridge of the hill in a region of strong terrain variations.

Occurrence of meridional and easterly surges and their impact on Malaysian rainfall during the northeast monsoon: a climatology study

AbstractThe cold surge or meridional surge (MS) is known to be one of the main features that contributes to extreme Malaysian rainfall events during the boreal winter or northeast monsoon. This study investigates other factors that contribute to the heavy rainfall, besides the cold surge, as well as their impacts on rainfall in the Malaysian region. Based on known methods, two additional types of surge are identified, namely the easterly surge (ES) and the mixed surge (MES), which is a mixture of both ES and MS. Daily average wind data from the European Centre for Medium‐Range Weather Forecasts Reanalysis ERA‐Interim for 37 seasons of the northeast monsoon (1979–1980 to 2016–2017, October–March) were used to identify the MSs, ESs and MESs. The impact of these surges on rainfall in the Malaysian region was investigated by using the rainfall data from the meteorological stations of the Malaysian Meteorological Department and the Tropical Rainfall Measuring Mission. The results showed that the MS plays an important role in modulating heavy rainfall in the early season over the east coast of Peninsular Malaysia. Meanwhile, the ES dominates the rainfall distribution over Sarawak in the late middle season. The rainfall modulated by the MES shows a higher intensity and concentrates over the southern part of the east coast of Peninsular Malaysia and Sabah. These findings provide a climatological view of the spatial and temporal distribution of heavy rainfall associated with different types of surge, which can be used as a forecasting tool for predicting surges and their impacts.

Optimal Planning of Grid Scale PHES Through Characteristics-Based Large Scale Data Clustering and Emission Constrained Optimization

In today’s modern power system, the proportion of renewable energy generation is increasing. The inherent frequent variability of these energy sources creates a power balance and frequency stability problem within the power system. Planning energy storage technologies for the mitigation of this fluctuation requires an analysis of large datasets whose competition is difficult as it increases the computation burden due to the increased variable size of the dataset. The generation of wind energy scenarios based on two notable wind energy generation characteristics and the use of representative data for the generated scenarios is proposed for the optimal sizing of energy storage tools. The IEEE-30 bus system with a one year hourly average wind data of the Northern Ireland wind resource was considered for the sizing of a pumped hydro energy storage (PHES) system. Fifteen data sets were generated and used in the emission constrained optimal sizing process using code written in MATLAB R2017a and particle swarm optimization (PSO) was used as the searching algorithm. The result proves that data grouping based on the combined average and variation method gives a better optimal storage size.

Evaluation of Wind Resources and the Effect of Market Price Components on Wind-Farm Income: A Case Study of Ørland in Norway

This paper aims to present a detailed analysis of the performance of a wind-farm using the wind turbine power measurement standard IEC61400-12-1 (2017). Ten minutes averaged wind data are obtained from LIDAR over the period of twelve months and it is compared with the 38 years’ data from weather station with the objective of determining the wind resources at the wind-farm. The performance of one of the wind turbines located in the wind-farm is assessed by comparing the wind power potential of the wind turbine with its actual power production. Our analysis shows that the wind farm under study is rated as ‘good’ in terms of wind power production and has wind power density of 479 W/m2. The annual wind-farm’s income is estimated based on the real-data collected from the wind turbines. The effect of price of electricity and the spot prices of Norwegian-Swedish green certificate on the income will be illustrated by means of a Monte-Carlo Simulation (MCS) approach. Our study provides a different perspective of wind resource evaluation by analyzing LIDAR measurements using Windographer and combines it with the lesser explored effects of price components on the income using statistical tools.

A Simulation Study on the Annual Power Increase with Active Induction Wind Farm Control including Wind Direction Change

Dynamic wind farm simulation tool developed from the previous study is used to study the annual power increase of the active induction wind farm control at an offshore site in Korea. The turbulent wind is generated from the veers model and the measured averaged wind data for 16 wind directions and used to estimate the power output of a virtual wind farm with 3 rows and 3 columns. A simple open loop wind farm control method was applied to find out the annual power increase considering the farm layout change according to the wind direction change. The power gains were found to be changed with different scale and shape parameters but the power increase was found to be very small.

Wind Energy Potential at Different Cities of Assam Using Statistical Models

Energy is an important role in any country’s economy and infrastructure growth. Wind energy is renewable form of energy and environment friendly compared to conventional energy resources that pollute the environment. A proper analysis of wind speed data is an important parameter to estimate wind energy potential at a particular site. This article investigates the wind energy potential at three different cities of Assam viz. Dibrugarh, Guwahati and Tezpur of Assam, India by using statistical methods over a period of eight years from 2010-2017. The speed data revealed that the mean wind speed of Tezpur city was lower in-comparison to Dibrugarh and Guwahati. The average wind speed of Dibrugarh is highest i.e. 5.398 km/hr followed by Guwahati city 4.628 km/hr. The average monthly wind data shows that the mean wind speed for city Dibrugarh is highest in the month of April as 7.8625 km/hr. The mean test analysis between Dibrugarh and Guwahati shows that the mean speed different between two cities is significant as P0.05. Weibull probability distribution function revealed that higher occurrence of probability at higher wind velocities for each city. The probability distribution plot shows that the 99% probability of occurance of Wind speed is 7.45093 km/hr for city Dibrugarh. The data also revealed that the average wind power density for the city Dibrugarh is 0.897451 W/m2 followed by city Guwahati 0.578349 W/m2. The above analysis shows that there is a possibility of wind power generation in the city of Dibrugarh followed by city Guwahati at these low wind speed region and the vertical axis wind turbines can be installed for power generation in cities Dibrugarh and Guwahati.

On the Anomalous Counterclockwise Turning of the Surface Wind with Time in the Plains of the United States

Vertical shear in the boundary layer affects the mode of convective storms that can exist if they are triggered. In western portions of the southern Great Plains of the United States, vertical shear, in the absence of any transient features, changes diurnally in a systematic way, thus leading to a preferred time of day for the more intense modes of convection when the shear, particularly at low levels, is greatest. In this study, yearly and seasonally averaged wind observations for each time of day are used to document the diurnal variations in wind at the surface and in the boundary layer, with synoptic and mesoscale features effectively filtered out. Data from surface mesonets in Oklahoma and Texas, Doppler wind profilers, instrumented tower data, and seasonally averaged wind data for each time of day from convection-allowing numerical model forecasts are used. It is shown through analysis of observations and model data that the perturbation wind above anemometer level turns in a clockwise manner with time, in a manner consistent with prior studies, yet the perturbation wind at anemometer level turns in an anomalous, counterclockwise manner with time. Evidence is presented based on diagnosis of the model forecasts that the dynamics during the early evening boundary layer transition are, in large part, responsible for the behavior of the hodographs at that time: as vertical mixing in the boundary layer diminishes, the drag on the wind at anemometer level persists, leading to rapid deceleration of the meridional component of the wind. This deceleration acts to turn the wind to the left rather than to the right, as would be expected from the Coriolis force alone.

Power calculation accuracy as a function of wind data resolution

Wind power calculations are usually based on average wind data taken over one-hour intervals. The effect of the wind data resolution on the statistical techniques used to calculate the probable power output (PPO) is commonly overlooked. This effect is analysed in this paper by iteratively calculating and comparing the PPO of a wind turbine using data, averaged over different periods, obtained from Wind Association of South Africa. The power is calculated using both Weibull representation and direct polynomial substitution techniques in order to compare and verify the results. The results indicate a fairly linear relationship between the resolution used and the PPO error incurred. These results raise an interest to examine the effects of a fine resolution on the data in terms of data dependence, which may violate the criteria for the majority of statistical tests and procedures.