Deployment Of Turbines Research Articles

Effects of land-based wind turbine upsizing on community sound levels and power and energy density

Multiple technological, social, and market factors of wind power are evolving rapidly. Most notably, significant wind turbine scaling is occurring and is forecasted to continue. While the larger turbines expected to be deployed in the future are more powerful and efficient, they are also expected to operate at higher sound levels and require larger setbacks than those installed in the last decade. These sometimes-competing deployment trends and impacts cannot be understood via simple extrapolations of past trends. This study analyzes the effect of these future larger turbines on wind turbine micro-siting, project-level power and energy density, and community noise impacts. Due to their taller heights, larger rotors, and higher sound power levels, future wind turbines will require larger setbacks from homes and greater inter-turbine spacing, resulting in fewer turbines deployed for a given land area. This research finds these changes more than offset the effect of the higher turbine sound emissions, significantly decreasing the average sound levels that wind plant hosting communities experience. Yet, simultaneously, plant layouts using future turbine designs also result in projects with higher installed capacities and annual energy output for a given land area. These increases will likely lead to increased tax benefits and local income in the community. The deployment of fewer turbines on a smaller number of parcels could have implications on siting flexibility and landowner payments.

Effect of Fouling on the Performance of an Instream Turbine

As the tidal energy industry starts to mature towards commercial projects a key focus is on reliable power performance. As for any marine application, fouling poses a potential performance reduction risk for instream turbine deployments.
 SCHOTTEL HYDRO have developed their current commercial SCHOTTEL Instream Turbines. Four drivetrains with 6.3m rotors were deployed on the surface platform PLAT-I by Sustainable Marine Energy. One of PLAT-Is key features is access to the turbines for inspection and maintenance in situ. The system has undergone sea testing from 2017 to 2021 in Scotland and Nova Scotia (Canada).
 This paper presents the hydrodynamic rotor performance reduction due to fouling based on full-scale experimental results. An in-house blade element momentum model is used to quantify the changes of the hydrodynamic forces in terms of lift and drag for the hydrofoils used. Furthermore, the effect of fouling on the downstream wake was quantified in the field. The performance reduction due to fouling is significant and leads to a power drop of up to 43%, whereas the thrust is reduced by 25%. This is also reflected in a reduction of the turbine’s downstream wake as a “fouled” rotor extracts less energy from the flow. Modifications of the polar data, used for semi-empirical performance predictions, are able to predict the effect of fouling on the rotor performance.
 In general, the results derived from the testing prove the significance of access to the turbines in order to avoid reduction in the turbines’ performance due to fouling.

Wind Energy on the High Seas: Regulatory Challenges for a Science Fiction Future

This paper aims to study the current regulation and governance of wind energy turbines on the high seas and detect regulatory challenges. We focus on the existing regulatory framework to develop marine wind farms in areas beyond national jurisdiction (ABNJ), the nature of wind farms and wind turbines in said areas, and which governance schemes and institutions ought to coordinate and regulate any future marine wind energy development. Our research shows that under public international law, the deployment of wind turbines on (most parts of) the high seas for all States is possible, but many issues still remain, either thinly regulated or unanswered. We inquire where, by whom, and how can marine wind parks be built on the high seas according to public international law and the United Nations Convention on the Law of the Sea (the LOSC). Lastly, we evaluate the possible role of marine spatial planning (MSP) in developing wind energy on the high seas.

Experts versus the Public: Perceptions of Siting Wind Turbines and Performance Concerns

Experiences of wind turbines (WT) shape public perception and acceptance of the technology, influencing government policy, deployment, and land-use policies of wind turbines. This paper attempts to find changes in public perceptions over the last three decades and differences between experts and the public over different land-use options. A semi-structured questionnaire that integrates a visual survey of 10 images of WT technology in different urban, landscape and seascape settings was presented to both groups. The perceptions of siting, proximity, landscape type, and maturity of urban wind turbines’ technology in renewable energy generation were contrasted. The results revealed that both the public and experts alike significantly preferred images of WT inclusion in seascape and landscape settings and responded negatively to images of WT as an addition to buildings in urban contexts. Images of wind turbines around transport settings were ranked in the second set of acceptances, after landscape settings, indicating that closer proximity to WT is acceptable, but for a short duration. The analysis also highlighted a preference by the public for aesthetically engaging WT, even if they resulted in lower energy yields, but were less accepted by the experts who based their judgment on technical performance.

The Physical Potential for Dutch Offshore Wind Energy

In the Netherlands, an important way to contribute toward achieving climate goals is the large-scale deployment of wind turbines in the North Sea. The North Sea is a unique location for offshore wind power thanks to its strong winds, shallow waters, and proximity to large energy users. Wind turbines generate electricity by extracting kinetic energy from the atmosphere. This kinetic energy is replenished at a finite rate through the mixing of atmospheric layers. The replenishment rate sets a physical limit to the amount of energy that can be sustainably extracted from a given area. In this study, we show that the Dutch Exclusive Economic Zone in the North Sea can sustainably host an installed capacity of approximately 59 GW on readily available space. By selecting areas fit for co-use, such as nature reserves and military zones, this amount can be increased to approximately 99 GW. With a calculated capacity factor of 45%, these areas can yield 240 and 381 TWh/yr, respectively, in the conservative and optimistic scenarios considered in this study, which correspond to approximately 39 and 62% of projected Dutch final energy demand in 2050. North Sea wind power is capable of supplying a significant amount of clean energy to Europe at large. Applying our approach to all North Sea countries combined implies that a capacity of approximately 418 GW can be sustainably installed in the North Sea under relatively conservative assumptions for water depth and distance from the shore. At a capacity factor of 43%, this can yield a power production level of as much as 1584 TWh/yr, which could satisfy approximately 40% of projected European electricity demand in 2050.

Experimental evaluation of power performance and wake characteristics of twin flanged duct turbines in tandem under bi-directional tidal flows

Ducted turbines have the potential to generate large-scale electricity when placed in tidal farms. Understanding the fluid-duct interaction would provide vital information for tidal farm projects. This paper describes flume experiments to investigate the performance and far wake impact on flanged duct turbines in bi-directional tidal flows. Results showed that ducted turbines generate 40% more power per rotor unit area than bare turbines. The turbines underperformed for each device in tandem configurations. However, ducted turbines outperformed bare turbines by 15%. The decreasing range of wake velocities and increasing turbulence intensities of the devices were shown to be greater in the ducted turbines. The drop in wake velocity is caused by kinetic energy extraction, and duct and rotor blockage effects. For the isolated bare and ducted turbines, full flow recovery occurs at around 13 and 20 rotor diameters, respectively. In tandem arrangements, while the bare turbine operated as if it was in isolation from 24 rotor diameters downstream, the wake flow in the ducted turbines persisted beyond. However, in terms of power output per rotor unit area, the deployment of additional ducted turbines may be advantageous. Though in the present state of development, precise economic estimates of energy costs are unavailable.

Decision support tools for improving land footprint and power generation of a photovoltaic field by the deployment of wind turbines in the same designated area: Eilat district as a case study

Decision support tools for improving land footprint and power generation of a photovoltaic field by the deployment of wind turbines in the same designated area: Eilat district as a case study

Development of a Hydrokinetic Turbine Backwater Prediction Model for Inland Flow through Validated CFD Models

Hydrokinetic turbine deployment in inland water reticulation systems such as irrigation canals has potential for future renewable energy development. Although research and development analysing the hydrodynamic effects of these turbines in tidal applications has been carried out, inland canal system applications with spatial constraints leading to possible blockage and backwater effects resulting from turbine deployment have not been considered. Some attempts have been made to develop backwater models, but these were site-specific and performed under constant operational conditions. Therefore, the aim of this work was to develop a generic and simplified method for calculating the backwater effect of HK turbines in inland systems. An analytical backwater approximation based on assumptions of performance metrics and inflow conditions was tested using validated computational fluid dynamics (CFD) models. For detailed prediction of the turbine effect on the flow field, CFD models based on Reynolds-averaged Navier–Stokes equations with Reynolds stress closure models were employed. Additionally, a multiphase model was validated through experimental results to capture the water surface profile and backwater effect with reasonable accuracy. The developed analytical backwater model showed good correlation with the experimental results. The model’s energy-based approach provides a simplified tool that is easily incorporated into simple backwater approximations, while also allowing the inclusion of retaining structures as additional blockages. The model utilizes only the flow velocity and the thrust coefficient, providing a useful tool for first-order analysis of the backwater from the deployment of inland turbine systems.

A mini-review of end-of-life management of wind turbines: Current practices and closing the circular economy gap.

Renewable energy generation and increased electrification are pivotal to reducing greenhouse gas emissions and mitigating climate change. Consequently, global deployment of wind turbines has soared, and the trend is expected to continue. Installed turbines have only recently started reaching the end of their design lives, and waste volumes are projected to escalate rapidly. Approximately 94% of a wind turbine (by mass) is recyclable, but the waste polymer composite blades are most commonly landfilled. This mini-review aims to review current end-of-life (EoL) management practices in the large-scale wind industry for countries with established EoL standards as well as those with less mature regulations. Data on current EoL management practices, initiatives and regulations in industry was sourced primarily from literature reviews and publicly available internet information. Additional insights and perspectives were gained from WindEurope's EoL Issues and Strategies 2020 seminar and through communication with select individuals from various sectors such as wind energy development and operations, government, industry associations, academia and research organizations. The results show that the decision on EoL options is dictated by the remaining useful life (RUL) of the wind turbines, prevailing policies and electricity prices. The contribution of this article is, firstly, identifying a number of key technical, economic and regulatory questions that must be asked before deciding on the most appropriate EoL option. Secondly, the article identifies factors that impede current EoL management efforts to close the circular economy gap and those that can support sustainable technology deployment. Finally, the article considers the way that countries with a young fleet of wind farms may learn from more experienced nations. There are few proven business cases, and barriers to the profitability and effectiveness of EoL strategies include uncertainty about the assets' RUL, collection logistics, the size of wind farm operation margins, low waste feedstock and limited markets for recycled products. Designing for circularity, stakeholder collaboration, circular business models and technology-specific regulations can improve EoL sustainability. The research found that wind turbine EoL management is dynamic and complex and needs to consider multiple, often conflicting factors. However, it is necessary and has immense environmental, technical and economic potential as the industry matures and business cases are proven.

Effect of Floating Offshore Wind Turbines on Atmospheric Circulation in California

In California offshore waters, sustained northwesterly winds have been identified as a key energy resource that could contribute substantially to California’s renewable energy mandate. It is these winds that drive upwelling, which is responsible for much of the primary productivity that sustains one of the richest ecosystems on the planet. The goal of this study is to quantify changes in wind fields at the sea surface as the result of offshore wind turbine deployments by use of an atmospheric model. Modeled wind fields from this study will drive an ocean circulation model. The Weather Research and Forecasting model was implemented on a regional scale along the U.S. west coast, with a higher resolution nest along the California continental shelf. Simulated arrays of offshore wind turbines were placed within call areas for wind farm development offshore of Central and Northern California. At full build-out, it was found that wind speeds at 10 m height are reduced by approximately 5%, with wakes extending approximately 200 km downwind of the nominated lease block areas. The length scale of wind speed reductions was found to be several times the internal Rossby radius of deformation, the spatial scale at which rotationally-influenced ocean circulation processes such as upwelling occur.

A predictive flight-altitude model for avoiding future conflicts between an emblematic raptor and wind energy development in the Swiss Alps.

Deployment of wind energy is proposed as a mechanism to reduce greenhouse gas emissions. Yet, wind energy and large birds, notably soaring raptors, both depend on suitable wind conditions. Conflicts in airspace use may thus arise due to the risks of collisions of birds with the blades of wind turbines. Using locations of GPS-tagged bearded vultures, a rare scavenging raptor reintroduced into the Alps, we built a spatially explicit model to predict potential areas of conflict with future wind turbine deployments in the Swiss Alps. We modelled the probability of bearded vultures flying within or below the rotor-swept zone of wind turbines as a function of wind and environmental conditions, including food supply. Seventy-four per cent of the GPS positions were collected below 200 m above ground level, i.e. where collisions could occur if wind turbines were present. Flight activity at potential risk of collision is concentrated on south-exposed mountainsides, especially in areas where ibex carcasses have a high occurrence probability, with critical areas covering vast expanses throughout the Swiss Alps. Our model provides a spatially explicit decision tool that will guide authorities and energy companies for planning the deployment of wind farms in a proactive manner to reduce risk to emblematic Alpine wildlife.

Wind power resource assessment and wind-hydrogen generation potential: a case study

ABSTRACT A case study of assessing wind power generation potentials for seven locations in a district of India is presented in the paper with special focus on small wind turbines with low cut in speeds operating in hybrid complementary mode with a hydrogen generation system. The major motivation for the study is to accelerate the efforts for the region toward carbon neutral status. The wind speeds are obtained for one hour time intervals for all days for 20 years during the time period 2001–2020 for the seven locations from European Center for Medium-Range Weather Forecasts Reanalysis v5 (ERA-5) data. Mean wind speeds for the period are analyzed and wind rose diagrams are generated using the WindroseAxes library in Python environment. Wind power potential assessment has been carried out using the data. From the analysis, it has been noted that the coastal and southern regions of the district get higher wind speeds and have higher power generation potential. Analysis has shown that based on the Beaufort scale, usually the available wind speed is in the calm to moderate breeze types (<0.3–8 m/s). Study has shown that deployment of small wind turbines may be beneficial, to potentially facilitate decentralized power generation. A small wind turbine with cut-in speed 2.5 m/s and cutoff speed 15.5 m/s is selected for the study. The region has a generic upper speed availability of 8 m/s. The corresponding wind power potential values are 0.84 and 27.58 kW. Hydrogen, considered as an energy carrier, and a clean fuel for the future, is proposed as an option for complementary energy storage. Hydrogen, generated from wind energy through electrolysis, may be stored and used to meet the peak power demands. A preliminary analysis of the hydrogen generation potential of the region via the power-to-gas route is also presented. The analysis also points to the necessity for developing small wind turbines, which can generate power at lower cut-in speeds, for maximum utilization of wind power generation potential. The methodology can be adapted to other regions.

Atlantic sturgeon presence in a designated marine hydrokinetic test site prior to turbine deployment: A baseline study

In 2009, the Fundy Ocean Research Centre for Energy (FORCE) developed a 1.6 x 1.0 km Crown Lease Area (CLA) to test Marine Hydrokinetic devices (MHKs) in Minas Passage (MP), a strait that connects the Bay of Fundy to Minas Basin (MB), Nova Scotia. Minas Basin is an important summer feeding aggregation site for numerous fishes including Atlantic sturgeon (Acipenser oxyrinchus Mitchill, 1815) stocks from Canada and the US. In this study, acoustic tagging technology was used to describe sturgeon presence in the CLA, as well as an adjacent site proposed for MHKs deployment. During 2018 and 2019, 33.9% (n = 19/56 Atlantic sturgeon tagged) and 29.9% (n = 23/77 Atlantic sturgeon tagged) respectively, of sturgeon acoustically tagged in MB during 2014–2019 were detected in these two FORCE sites. Binomial General Linear Models (GLMs) were fit to determine if environmental parameters influenced the presence, or depth of Atlantic sturgeon in the FORCE sites. The only significant predictor of Atlantic sturgeon depth and presence at the FORCE sites was tide type. Atlantic sturgeon was found to have a higher likelihood of being detected during ebb tide (12%) as opposed to flood tide (3%). Apparent decline in the presence of sturgeon during flood tide was probably due to poor signal reception caused by turbulence from higher current speeds. Tagged sturgeon travelled through the FORCE sites pelagically at similar depths (27.5 ± 14.57 m) to those proposed for seabed mounted MHKs (~30 m), travelling deeper during flood tide than ebb, suggesting they may be at risk of spatial overlap with MHKs. While this study indicated that the duration Atlantic sturgeon utilized the FORCE sites throughout the summer appeared to be low, sturgeon from both endangered and threatened stocks migrated through this region during their yearly entry and exit to MB and were present for approximately 12% of the days assessed in this study.

Tidal current resource assessment and study of turbine extraction effects in Banks Strait, Australia

Banks Strait, Australia has been identified as highly promising for tidal turbine deployments. To assess this site's feasibility, high-resolution unstructured mesh two-dimensional (2D) models were generated using the newly developed COMPAS hydrodynamic model. Model results were calibrated and validated against results from five Acoustic Doppler Current Profiler field datasets. Simulation results indicating that considerable tidal energy resources exist, with maximum tidal currents of almost 3 m/s found at depths suitable for both small and large-scale Tidal Energy Converters (TEC) array installations, making this region promising for tidal energy extraction for both on and off-grid energy demands. Two examples of tidal farms consisting of a 1.2 MW array of 3 m diameter TEC's in shallow water and a 60 MW array of twin-rotor 20 m diameter TEC's in deep water were then simulated. The study used two methods to determine farm power output using the 2D models: the first method estimated the output directly from current velocity predictions based on the developed resource model, whilst the second method simulated the TEC energy extraction using a bottom friction model. For both TEC arrays minimal changes in near and far-field mean current flow and surface elevations were found.

Power Maximization and Turbulence Intensity Management through Axial Induction-Based Optimization and Efficient Static Turbine Deployment

Layout optimization is capable of increasing turbine density and reducing wake effects in wind plants. However, such optimized layouts do not guarantee fixed T-2-T distances in any direction and would be disadvantageous if reduction in computational costs due to turbine set-point updates is also a priority. Regular turbine layouts are considered basic because turbine coordinates can be determined intuitively without the application of any optimization algorithms. However, such layouts can be used to intentionally create directions of large T-2-T distances, hence, achieve the gains of standard/non-optimized operations in these directions, while also having close T-2-T distances in other directions from which the gains of optimized operations can be enjoyed. In this study, a regular hexagonal turbine layout is used to deploy turbines within a fixed area dimension, and a turbulence intensity-constrained axial induction-based plant-wide optimization is carried out using particle swarm, artificial bee colony, and differential evolution optimization techniques. Optimized plant power for three close turbine deployments (4D, 5D, and 6D) are compared to a non-optimized 7D deployment using three mean wind inflows. Results suggest that a plant power increase of up to 37% is possible with a 4D deployment, with this increment decreasing as deployment distance increases and as mean wind inflow increases.

Data-driven robust dispatch for integrated electric-gas system considering the correlativity of wind-solar output

The increasing popularity of distributed renewable power generation represented by wind turbines and solar plants and the deployment of gas turbines (GTs) and power-to-gas (P2G) facilities have promoted stronger interdependence between the power grid and the natural gas system, which makes the economic dispatch of the integrated electrical and gas system (IEGS) more challenging. This paper proposes a two-stage dispatch model for distribution-level IEGS based on a data-driven robust optimization (DDRO) method. First, for distribution-level IEGS, a network model of IEGS is established, and the nonconvex constraints are relaxed by the big M method and second-order cone (SOC) relaxation. Considering the correlation between wind and solar output in multiperiod, a wind-solar output ellipsoid uncertain set is constructed through the minimum volume enclosed ellipsoid (MVEE) algorithm to obtain extreme scenarios. Finally, a column-and-constraint generation (C&CG) method based on extreme scenarios is proposed to solve the two-stage robust optimization model. Simulation results show that the proposed DDRO method can reduce the day-ahead and real-time dispatch costs of energy conversion equipment while ensuring the robustness of IEGS system dispatch. In addition, the economics of IEGS system dispatch is improved.

Prediction of wind turbine blade trailing edge noise under various flow conditions for a passive damage detection system

Noise generated by turbulent boundary layer over the trailing edge of a wind turbine blade under various flow conditions is predicted and analyzed for structural health monitoring purposes. Wind turbine blade monitoring presents a challenge to wind farm operators, and an in-blade structural health monitoring system would significantly reduce O&amp;M costs. Previous studies into structural health monitoring of blades have demonstrated the feasibility of designing a passive detection system based on monitoring the flow-generated acoustic spectra. A beneficial next step is identifying the robustness of such a system to wind turbine blades under different flow conditions. To examine this, a range of free stream air velocities from 5 m/s to 20 m/s and a range of rotor speeds from 5 rpm to 20 rpm are used in a reduced-order model of the flow-generated sound in the trailing edge turbulent boundary layer. The equivalent lumped acoustics sources are predicted based on the turbulent flow simulations, and acoustic spectra are calculated using acoustic ray tracing. Each case is evaluated based on the changes detected when damage is present. These results can be used to identify wind farms that would most benefit from this monitoring system to increase efficiency in deployment of turbines.

A review of component and system reliability in tidal turbine deployments

Tidal stream energy has the potential to contribute to global renewable energy generation, but this remains largely untapped. Technical developments have helped create a nascent industry with several pre-commercial installations. However, planned projects experience a cautious investment climate due to perceived risk of failure, and maintenance and repair cost. This paper reviews 58 tidal stream energy deployments between 2003 and August 2020. The analysis reviews commonalities, success and engineering issues, to inform current and future projects. The work classifies each deployment by type, rated power, number of devices, grid connection and foundation. In each case, project status and (if appropriate) failure mode is identified. Failure modes are compared to deployment classification to identify potential relationships. Most deployments were of horizontal axis turbines. The majority (54%) of deployments performed well. 18% failed, 14% were withdrawn from service, and 14% generated less power than planned. The most common failure cause was blade failure, followed by generator and monitoring failures. Ducted devices and devices in high velocity locations were more likely to fail, suggesting that flow velocity is a key factor. Most blade failures were attributed to underestimation of loads during design. Floating deployments were less likely to fail than fixed deployments, but more likely to be curtailed. Off-grid and grid connected deployments showed similar failure rates, suggesting sector immaturity. Tidal stream energy has accumulated around 1.4 million operating hours. Analysis shows a falling empirical failure rate, and likelihood of failure similar to that experienced by the wind industry at a similar stage. This work will be useful for project planners, developers and technology companies and investors in de-risking future project efforts.

Modelling Morphological Changes and Migration of Large Sand Waves in a Very Energetic Tidal Environment: Banks Strait, Australia

Banks Strait, Tasmania, Australia, has been identified as a potential site for the deployment of tidal turbines. In this study, the characterization of sediment transport and large sand waves for this site is performed. Observations of bed level change collected from surveys in 2018 showed a migration of large sand waves over a period of nine months. Migration rates in an excess of one hundred meters for nine months were found, which are large compared to the rate reported at other coastal sites, by several meters per year. A validated hydrodynamic model is coupled with a morphodynamic model to perform sensitivity tests and identify what parameters influence migration to better understand sediment dynamic in the Banks Strait. Numerical analysis showed a constant shift of the sand waves profile in an eastward direction, consistent with the observations. This migration was strongly linked with tidal asymmetry, with a residual current flowing towards the east. The principal parameters driving the migration of sand waves in the Banks Strait were found to be sediment sorting, bed friction and residual current. This study gives new insights for the seabed of Banks Strait and provides an assessment of the natural variability of sediment for futures tidal farms deployments.

Evaluating the complementarity of solar, wind and hydropower to mitigate the impact of El Niño Southern Oscillation in Latin America

Latin America has the largest share of renewable energy for power generation in the world, but has historically been dependent on hydropower, and is vulnerable to long-term phenomena like the El Niño-Southern Oscillation (ENSO). The region is currently experiencing a steady increase in gas-based power generation along with a rapid growth in non-hydro renewables, mainly aimed at improving reliability. But exploiting complementarities between hydropower and other renewables could offer additional benefits. This paper investigates to what extent improved deployment of wind turbines and solar photovoltaic cells (PV), aimed at complementing existing hydropower, could mitigate the impacts of ENSO in Latin America. We use a meteorological reanalysis dataset to model the variations in wind-, solar- and hydropower throughout the entire 20th century and their association with different ENSO phases in the same period. A statistical algorithm is then used to identify locations at national and regional levels offering the maximal level of complementarity. The results show that adding 136 GW of wind- and solar-power with high-complementarity has the potential to cost-effectively compensate the fluctuations of hydropower and reduce the variability of renewable power not only during drought ENSO phases but also outside ENSO events. Benefits include: (i) an increase of up to 5-fold the minimum threshold of renewable power available every month, (ii) a reduction of up to 65% in the variability of renewable power generation, and (iii) reaching a levelized cost of electricity (LCOE) of 0.09–0.23 $/kWh, which is comparable to that of new gas plants.