Expansion Of Wind Energy Research Articles

Modeling Wind Speed with a Long-Term Horizon and High-Time Interval with a Hybrid Fourier-Neural Network Model

The limited availability of local climatological stations and the limitations to predict the wind speed (WS) accurately are significant barriers to the expansion of wind energy (WE) projects worldwide. A methodology to forecast accurately the WS at the local scale can be used to overcome these barriers. This study proposes a methodology to forecast the WS with high-resolution and long-term horizons, which combines a Fourier model and a nonlinear autoregressive network (NAR). Given the nonlinearities of the WS variations, a NAR model is used to forecast the WS based on the variability identified with the Fourier analysis. The NAR modelled successfully 1.7 years of wind-speed with 3 hours of the time interval, what may be considered the longest forecasting horizon with high resolution at the moment.

Sounding out the repowering potential of wind energy – A scenario-based assessment from Germany

Wind energy in Germany is awarded a crucial role in increasing the share of renewable energies in the electricity mix to 65% until 2030, especially in light of the federal government’s recent decision to phase out coal-based electricity until 2038. In addition to the targeted expansion of wind energy, Germany will be struggling with thousands of wind turbines at the end of their service life in the next years. To advance the expansion of wind energy and to increase its efficiency, repowering is deemed a promising way to deal with the upcoming changes in wind energy use. This study assesses Germany’s repowering potential in 2021–2040. It estimates how many of the existing wind turbine sites in Germany can be used for repowering without violating recently recast geographical restrictions while at the same time meeting proper spacing criteria for repowered wind turbines. The results from fifteen scenarios indicate the repowering potential in Germany to be highly impacted by the recast geographical restrictions and wind turbine categories used to repower. Compared to the energy contributed by onshore wind in the baseline year 2021, the best-case scenario could provide 110%. In contrast, the worst-case scenario could provide 40% of potential wind energy generation in 2040. The highest potential wind energy generation is reached under low distance restrictions of 500 m to surrounding settlement areas. The results indicate repowering alone to be unable to substantially increase the share of wind energy in Germany’s energy mix over the next two decades. Without expansion, the contribution of wind energy to Germany’s energy mix will diminish. However, despite the growing number of old wind turbines in Germany, repowering still offers more efficient exploitation of the wind resource.

Evaluation of the lattice Boltzmann method for wind modelling in complex terrain

Abstract. The worldwide expansion of wind energy is making the choice of potential wind farm locations more and more difficult. This results in an increased number of wind farms being located in complex terrain, which is characterised by flow separation, turbulence and high shear. Accurate modelling of these flow features is key for wind resource assessment in the planning phase, as the exact positioning of the wind turbines has a large effect on their energy production and lifetime. Wind modelling for wind resource assessments is usually carried out with the linear model Wind Atlas Analysis and Application Program (WAsP), unless the terrain is complex, in which case Reynolds-averaged Navier–Stokes (RANS) solvers such as WindSim and Ansys Fluent are usually applied. Recent research has shown the potential advantages of large-eddy simulation (LES) for modelling the atmospheric boundary layer and thermal effects; however, LES is far too computationally expensive to be applied outside the research environment. Another promising approach is the lattice Boltzmann method (LBM), a computational fluid technique based on the Boltzmann transport equation. It is generally used to study complex phenomena such as turbulence, because it describes motion at the mesoscopic level in contrast to the macroscopic level of conventional computational fluid dynamics (CFD) approaches, which solve the Navier–Stokes (N–S) equations. Other advantages of the LBM include its efficiency; near-ideal scalability on high-performance computers (HPCs); and ability to easily automate the geometry, the mesh generation and the post-processing. However, the LBM has been applied very little to wind modelling in complex terrain for wind energy applications, mainly due to the lack of availability of easy-to-use tools as well as the lack of experience with this technique. In this paper, the capabilities of the LBM to model wind flow around complex terrain are investigated using the Palabos framework and data from a measurement campaign from the Bolund Hill experiment in Denmark. Detached-eddy simulation (DES) and LES in Ansys Fluent are used as a numerical comparison. The results show that there is in general a good agreement between simulation and experimental data, and the LBM performs better than RANS and DES. Some deviations can be observed near the ground, close to the top of the cliff and on the lee side of the hill. The computational costs of the three techniques are compared, and it has been shown that the LBM can perform up to 5 times faster than DES, even though the set-up was not optimised in this initial study. It can be summarised that the LBM has a very high potential for modelling wind flow over complex terrain accurately and at relatively low costs, compared to solving N–S equations conventionally. Further studies on other sites are ongoing.

Trade-offs and synergies in the water-energy-food nexus: The case of Saskatchewan, Canada

Socioeconomic and climatic changes and limited water resources pose various challenges to water, energy, and food sectors across the globe. The inevitable interactions between water, energy, and food systems bring about trade-offs but also synergies under different decisions and policies. To gain insights into these issues, we developed a water-energy-food (WEF) nexus model that incorporates both production (supply) and demands sides of WEF systems into a single system-of-systems model using the system dynamics (SD) approach. The model is applied to Saskatchewan, Canada, and so is named WEF-Sask. The model results reveal the various levels of sensitivities of water, energy, and food (and feed) sectors to the socioeconomic and climatic drivers. The analysis of trade-offs and synergies shows that the proposed large irrigation expansion (400%) boosts food production by 1.6% while reducing hydropower production by 2.7% in Saskatchewan. Wind energy expansion strategy (from 5% to 30% of total capacity) makes synergies that not only contribute to electricity supply but also reduce greenhouse gas emissions, industrial water demand, and groundwater use by 2.0, 5.7, and 3.8%, respectively. Biofuel use (blending mandate: 10% ethanol and 5% biodiesel) in transportation cuts GHG emissions by 1.2% but reduces the potential food export (food surplus) by 5.0%. The WEF-Sask model allows for scenario analysis toward integrated resources management, and its generic model structure can be expanded to other regions.

Introducing a new approach for wind energy potential assessment under climate change at the wind turbine scale

An important aspect of planning the future expansion of wind energy is the consideration of changes in available wind resources due to climate change. In previous studies simulations of the future behavior of wind resources were derived from regional climate models at coarse spatial resolutions not suitable for wind energy potential assessment at the wind turbine scale. Thus, this study investigates the hypothesis that changes in future wind resources initiated by climate change will influence important aspects of small-scale wind resource assessment. A new approach is introduced that can be used to quantify the (1) spatial wind resource availability, (2) temporal wind resource availability, and (3) geographical complementarity under climate change at the wind turbine scale. The assessment of the future spatiotemporal variations in wind resources is based on an ensemble of near-surface (10 m) wind speed time series at a daily resolution for the period 1981–2099 from 35 different regional climate models. Using the highly resolved (horizontal resolution: 200 m × 200 m) Wind Speed-Wind Shear model, the near-surface wind speed time series were bias-corrected and extrapolated to a wind turbine hub height of 140 m at the sites of the current wind turbines in Germany. Bias correction was carried out by matching the quantile distributions from the regional climate models and the Wind Speed-Wind Shear model. Afterward, a power curve of a modern 3.45 MW wind turbine was applied to calculate daily capacity factors. The results indicate small long-term changes in the wind resource availability under the representative concentration pathways 4.5 and 8.5. It was found, that the influence of the interannual variability of the German wind resource exceeds the influence of climate change on the wind resource. The newly developed approach goes beyond previous wind resource assessments under climate change because it offers the opportunity for the spatially explicit investigation of different aspects of wind resource assessment which allows to develop more sophisticated wind energy expansion plans. Although the results are valid only for the study area, the proposed methodology is portable to any other region around the world.

Factors Affecting the Community Acceptance of Onshore Wind Farms: A Case Study of the Zhongying Wind Farm in Eastern China

The conflict between wind energy expansion and local environmental protection has attracted attention from society and initiated a fierce discussion about the community acceptance of wind farms. There are various empirical studies on factors affecting the public acceptance of wind farms, but little concerning the correlation and significance of factors, especially in a close distance to the wind farms. This paper aims to identify, classify, and analyze the factors affecting community acceptance through literature review, questionnaire, variance analysis, and linear regression analysis. A total of 169 questionnaires was conducted in 17 villages around the Zhongying Wind Farm in Zhejiang Province, China. The factors are categorized into four groups: Location-related factors, demographic factors, environmental impact factors, and public participation factors. Through the analysis of variance (ANOVA) and linear regression analysis, the outcome shows the universal rule of community acceptance under the Chinese social background. Finally, recommendations for improving wind farm planning procedures are put forward.

Statistical correction scheme for the wind power allocation to transformer stations in the transmission grid

The expansion of photovoltaics and wind energy shifts the feed-in from the transmission grids down to the lower voltage levels of the distribution grids. It is a challenging task to determine at which transformer station of the extra-high voltage grid photovoltaic and wind energy is fed via the cascade of the different grid levels. In principle, this allocation problem of generation to transformer stations can be solved with a power flow calculation if the topology and parameters of all grids are known. In reality, however, this knowledge is spread over several grid operators and alternative solutions could be promising. We propose a method for inversely correcting an initially estimated allocation of wind power generators to transformer stations between the transmission and the distribution grid based on correlating the wind power feed-in with the vertical power flows measured at the considered transformer stations.Our experimental setup involves the allocation optimization of about 29 GW of installed wind power to 136 transformer stations within the two largest German control zones. By shifting a total amount of 12.6 GW of allocated wind power between these transformer stations, our scheme is able to detect and correct erroneous allocations and to improve the reliability of the estimated wind power feed-in per transformer station.

Scour around a monopile induced by directionally spread irregular waves in combination with oblique currents

The progressive expansion of offshore wind energy towards greater water depths demands for an optimization of foundation structure designs to a wider range of load conditions. In offshore waters, wind driven wave irregularity and directionality become important aspects of realistic sea states. To further improve the scour prediction in marine environment a novel experimental study was conducted to investigate the influence of directionally spread (3D) irregular waves on the scouring process. The tests were carried out in the 3D wave basin of the Ludwig-Franzius-Institute, Leibniz University Hannover, Germany. A monopile structure was simulated by a transparent pile made of acrylic glass. The study was set up to progress understanding and explore dissimilarities of scour development and patterns induced by directionally spread (3D) and unidirectional (2D) waves. The model tests were complemented by tests with superimposed oblique currents. Despite identical total wave energy in terms of m0 between the directionally spread and unidirectional wave spectra, minor but distinct differences in scour depth and rate could be observed, which inevitably can only be attributed to the presence and role of the wave spread. For wave-only conditions final scour depths S/D induced by directionally spread waves were on average 33% smaller than those for unidirectional waves. Furthermore, final scour depths decreased with increasing wave spreading and displayed a growing dependency on KC numbers with increasing wave spreading. In combined wave and current conditions of up to Ucw < 0.62 scour depths were found to be slightly larger and scour progression over time faster for directionally spread than for unidirectional waves. Differences regarding the scouring rates and depths have been found to decline with flow conditions further approaching current dominated regime. A prediction approach to estimate the maximum scour depth induced by either directionally spread or unidirectional random waves is proposed. Reasonable results and insights of the present study help advancing the understanding of scour development under more realistic, i.e. natural sea-state, conditions for a more reliable design of marine and offshore infrastructure.

The Cost of Wind: Negative Economic Effects of Global Wind Energy Development

This paper provides a structured literature review of the negative economic effects associated with the development of wind energy and synthesized the evidence at an abstract level. We then developed an analytical framework to systematically review economic issues such as volatility, electricity price, housing values, and unemployment in relation to wind energy. Global wind energy development data from the time period from 2000 through 2019 were included for a more robust analysis. This period encompasses the vast majority of total global installed wind energy capacity. After amalgamating evidence from existing studies and data banks, we discuss the policy implications, suggest avenues for future research, and propose solutions to mitigate externalities. By understanding the negative economic impact created by the expansion of wind energy, we can better equip policy makers and developers to create more efficient and sustainable energy policy to benefit citizens and preserve the environment for generations to come.

Wind energy counter-conducts in Germany: understanding a new wave of socio-environmental grassroots protest

ABSTRACT The rapid expansion of wind farms in Germany has spurred debate over the environmental impacts of the Energiewende, the country’s plan to transition towards renewable energy sources. We explore the opposition to two wind farms in central Germany by local civil initiatives through the Foucauldian notion of counter-conducts and a related Analytics of Protest Framework. Employing qualitative interpretive research methods, including 27 semi-structured interviews, we examine how wind energy critics navigate practices and rationalities governing wind energy expansion in the context of the Energiewende. We argue that critics challenge imperatives of environmental protection and energy justice, while at the same time reinforcing them. Struggles over wind energy manifest as struggles over the legitimate object of environmental protection and the ethical constitution of an environmental subject. Landscapes, both as habitats and scenery, gain impetus as the central tenet in the ecological agenda of wind energy opponents.

Roe deer stress response to a wind farms: Methodological and practical implications

There is an insufficient number of field studies on the impact of wind farms on ungulates despite the rapid expansion of world wind energy. The results of previous studies suggests a possible impact of power plants, but they are divergent and do not take into account the size of wind farms. We examined the impact of wind farms on the stress levels in roe deer based on seven wind farms of various sizes (of 12–27 turbines) in eastern Poland. Fecal cortisol concentration was assessed with the ELISA method in droppings collected during the winter period. We found that the roe deer exhibited an elevated stress level in the area of larger farms, but such response was not found in the case of smaller wind farms. The roe deer were also characterized by a higher stress level in areas of wolf predation, but this factor was less important. Both the area of the farm and the number of turbines explained the phenomenon of the increased stress in the roe deer. We estimated 824 ha or 18 turbines as a threshold level of the impact of wind farms on the cortisol concentration in the roe deer. We conclude, that turbines should be concentrated in the smallest possible area. In such conditions, roe deer will probably be able to find appropriate refuges. We recommend further studies on wind farms older than 4 years and the distribution of turbines.

Computational analysis of the transportation phase of an innovative foundation for offshore wind turbine

ABSTRACT As the global demand for energy rises, renewable sources are increasingly becoming more accessible, and oceans show an excellent possibility for the expansion of wind energy. In this work, the structural integrity and the stability during the transportation of an innovative foundation for offshore wind turbines with self-floating capability are evaluated. The structure, with the turbine already installed, is transported to the installation site in its floating position assisted by towing vessels, being then submerged and fixed into the marine soil through suction piles. This paper focuses on the development of adequate numerical models to analyse the magnitude of the loadings subjected into the structure during transportation. FAST and AQWA are used to determine these aerodynamic and hydrodynamic loadings. The obtained results provide the necessary input data for the structural analysis using ANSYS to evaluate the stresses registered on the structure, as well as its vibration modes and stability.

TOP-DOWN AND BOTTOM-UP POLICY IMPLEMENTATION APPROACH – THE CASE OF WIND POWER DEVELOPMENT IN THE NORDIC COUNTRIES AND THE REPUBLIC OF SERBIA

Environmental policy integration (EPI) is the incorporation of environmental concerns in sectoral policies outside the conventional environmental policy domain. Dealing with such concerns is necessary because research indicated that the institutional specialization of policies for specific sectors has resulted in insufficient consideration of environmental impacts, as sectoral policies might have objectives in conflict with environmental objectives and are able to influence the root causes of environmental pressure. There is a consensus that the link between environment and energy policies has transformed and modified the energy policy in Europe, not the least by the potential of renewable electricity (RES-E). Therefore, studying the RES-E perspective within an EPI initiative is relevant and the present article aims to contribute to a more sector-specific understanding of EPI. More precisely, by focusing on the conditions for the expansion of wind energy in the Nordic countries and Serbia, the present research aims to illustrate the necessity of understanding the national, regional and local contexts for more effective RES-E implementation.

Satellite telemetry and digital aerial surveys show strong displacement of red-throated divers (Gavia stellata) from offshore wind farms

Expansion of offshore wind energy is vital for the reduction of CO2 emissions. However, offshore wind farms may negatively impact the environment without proper planning. Here we assess the robustness of the conclusions of earlier studies that the strictly protected red-throated diver, Gavia stellata, is strongly displaced from wind farms in the German Bight (North Sea). We modelled the distribution of divers based on two independent data sets, digital aerial surveys and satellite telemetry, in relation to the dynamic offshore environment and anthropogenic pressures. Both data types found that divers were strongly displaced from wind farms in suitable habitat. The displacement effect gradually decreased with distance from the wind farms (being very strong up to 5 km away), but a significant effect could be detected up to 10–15 km away. The telemetry data further indicated that the displacement distance decreased with decreasing visibility. The displacement distance was also shorter during the day than during the night, potentially as a response to aviation and navigation lights of the wind farms. These findings should be taken into consideration in marine spatial planning to avoid cumulative impacts on red-throated diver populations.

The marine economy of the United Kingdom

The marine and coastal environment is an important economic asset in the UK, and there is a need for greater information about marine economic activities for the purposes of marine management and policy. However, due to the difficulties of quantifying some marine sectors and separating them from terrestrial activities, the current size and structure of the marine economy is unknown. This paper defines a systematic approach to quantifying the UK marine economy, aiming to capture all activities in the market economy that occur within and depend upon UK marine and coastal environments, and estimates its contribution to the UK economy as a whole. The approach draws on previous research in this area and links sectors used in marine planning with the methodologies used in national accounts. The results suggest that the marine economy contributes double the amount of previous estimates to the UK economy. Changes in the structure of the marine economy, partly due to the expansion of offshore wind energy, may affect its economic contribution. The results also show that marine and coastal leisure and recreation sectors, which were previously thought to have a small economic contribution, are the second largest sector in the UK marine economy and account for the largest number of jobs. By disaggregating the economic sectors, the approach used here can underpin a marine natural capital approach, enabling economic activities to be linked with aspects of marine natural capital.

Effects of Wind Turbine Curtailment on Bird and Bat Fatalities

ABSTRACTBird and bat fatalities increase with wind energy expansion and the only effective fatality‐reduction measure has been operational curtailment, which has been documented for bats but not for birds. We performed opportune before‐after, control‐impact (BACI) experiments of curtailment effects on bird and bat fatalities and nocturnal passage rates during fall migration at 2 wind projects, where 1 continued operating and the other shut down from peak migration to the study's end (study 1). We also performed BACI experiments during a 3‐year study of curtailment and operational effects on bird fatalities among wind turbines of varying operational status (study 2). In study 1, wind turbine curtailment significantly reduced near‐misses and rotor‐disrupted flights of bats, and it significantly reduced fatalities of bats but not of birds. In study 2, converting wind turbines from inoperable to operable status did not significantly increase bird fatalities, and bird species of hole or sheltered‐ledge nesters or roosters on human‐made structures died in substantial numbers at vacant towers. Of bird species represented by fatalities in study 2, 79% were found at inoperable wind turbines. Because the migration season is relatively brief, seasonal curtailment would greatly reduce bat fatalities for a slight loss in annual energy generation, but it might not benefit many bird species. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.

How to achieve the climate targets? Spatial planning in the context of the German energy transition

BackgroundThe transition of the energy system to renewable energy depends on how successfully the national objectives can be implemented at the lower planning levels. Germany pursues an incentive-oriented policy that is not spatially targeted and lets regional and local stakeholders determine where and how renewable energies are used.A core question is how to achieve the national goals, in a federal system that allows freedom of planning for the local communities. The aim of this paper is to show the discrepancies between the current expansion of wind energy and the necessary expansion that is derived from a scientific analysis.MethodsThe study examined the policy objectives for the expansion of wind energy, based on a literature analysis. In a second step, the regulatory competences and spatial planning at the various levels and their influence on the expansion were explored. In a third step, the current procedure was compared with scientific scenarios of the energy system in 2050 and concretized using the example of the Hannover Region.ResultsThe theoretical and empirical analysis shows that people at regional level underestimate their responsibility for contributing to energy transition. The expansion targets for wind energy in the Hannover Region projected in the scientific scenario are above the minimum demand that the local authorities have assumed. The same applies to the state of Lower Saxony, which underestimates its own wind energy potential and thus its necessary contribution to achieving the national targets.ConclusionsWe propose a nationwide coordinated strategy for the successful implementation of the energy transition. With the methodology described, regional targets can be determined and the responsibility of the region and the local actors can be clarified. With the help of spatial planning and public participation, the energy transition can be achieved with this approach.

3-D Layout Optimization of Wind Turbines Considering Fatigue Distribution

As wind resources and land resources become increasingly strained with the rapid expansion of wind energy, the problem of getting a better micro-sitting of wind turbines has gained more and more concerns in the wind industry. A methodology of three-dimension layout of wind turbines (WTs) is proposed in this paper to optimize the horizontal layout and vertical hub height simultaneously. New development of low speed WT technology and influences of micro-sitting of WTs to their O&M costs are considered for the first time. A nested loop consisting of a harmony search algorithm-based layout optimization and a sorting genetic Algorithm-II (NSGA-II)-based turbine selection is also presented to deal with the multi-objective functions. In the optimization process, a polar coordinate transformation-based wake effect model is conducted to simplify the wake effect calculations among the multiwind turbines with different hub height and rotor diameters when the wind direction changes. A 100 MW wind farm case is discussed to illustrate the flexibility and performance improvements of the proposed methodology.

Meteorological Aspects of Self‐Initiated Upward Lightning at the Säntis Tower (Switzerland)

AbstractInterest in exploring the meteorological conditions favoring upward lightning from tall man‐made structures has grown in recent years, largely due to the worldwide expansion of wind energy. To this end, instrumented towers existing around the world are the most suitable places to study upward lightning. In this context, an LMA network was deployed around the Säntis Mountain (northeast Switzerland) during the summer of 2017, in order to complement the long‐term measurements currently held at the Säntis telecommunications tower, a lightning hot spot in central Europe. This campaign allowed, for the first time, to gather a comprehensive set of observations of self‐initiated upward lightning emerging from the Tower. With the help of C‐band dual‐polarimetric radar data, the present work focuses on the meteorological conditions conductive to self‐initiated upward lightning from the Säntis. The analysis revealed that the upward propagating positively charged leaders spread mostly horizontal above the melting level, after an initial short vertical path from the tower tip. After this initial stage, the majority of upward leaders were followed by a sequence of negative return strokes. The inception upward lightning under a stratiform cloud shield would be favored by the low height of the charge structure. From the obtained results, it turns out that a key feature favoring self‐initiated upward lightning would be the proximity of the tower tip to the melting level.

Using a new USA multi-region input output (MRIO) model for assessing economic and energy impacts of wind energy expansion in USA

The share of wind energy in the US energy supply has been steadily increasing in the last two decades. With new wind energy farms being installed in various states of the country, local and multi-regional economic disruptions are bound to take place. The multi-regional economic impacts of installing new wind farms was determined using the US multi-region input-output (US-MRIO) model that has been developed, also called the USLab. Currently, there is a lack of multi-regional impact assessment of wind energy expansion in the US. In this article, we use the US-MRIO to determine regional and sectoral spill-over effects resulted from installation of wind energy farms in 10 US states. The economic impacts were calculated by feeding the USLab with data obtained from the Jobs and Economic Development Impacts (JEDI) Wind model published by National Renewable Energy Laboratory (NREL). The JEDI wind model provides the change in local economic data such as the number of new jobs created and increase of energy-related products in each region in the final demand and value-added. The data about final demand and value-added change was used with the US-MRIO model to account for the multi-regional economic impact across US due to installation of wind energy farms. The year of wind farm installation was set to 2017 and a US-MRIO for 2017 was generated to calculate the economic impact. The total economic impact was found to be 26 billion dollars of which 3 billion dollars was associated with the states where no new wind energy capacity was installed. Installation of new energy production capacity also results in “change in energy consumption” across US. Using the US-MRIO model and the energy intensity of manufacturing sectors, the energy consumption increase due to addition of wind farms was found to be about 6952 trillion of btu for the total change in economic throughput. Primary metal manufacturing and Machinery manufacturing sectors stood out amongst other manufacturing sectors with considerable change in energy consumption with an increase of 3074 trillion of btu and 1537 trillions of btu.