scholarly journals Maintenance Models Applied to Wind Turbines. A Comprehensive Overview

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 225 ◽  
Author(s):  
Yuri Merizalde ◽  
Luis Hernández-Callejo ◽  
Oscar Duque-Perez ◽  
Víctor Alonso-Gómez
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Comprehensive Overview ◽  
Fossil Energy ◽  
Operation And Maintenance ◽  
Cost Of Energy ◽  
Wide Range ◽  
Different Types ◽  
The Cost ◽  
Machine Learning Models

Wind power generation has been the fastest-growing energy alternative in recent years, however, it still has to compete with cheaper fossil energy sources. This is one of the motivations to constantly improve the efficiency of wind turbines and develop new Operation and Maintenance (O&M) methodologies. The decisions regarding O&M are based on different types of models, which cover a wide range of scenarios and variables and share the same goal, which is to minimize the Cost of Energy (COE) and maximize the profitability of a wind farm (WF). In this context, this review aims to identify and classify, from a comprehensive perspective, the different types of models used at the strategic, tactical, and operational decision levels of wind turbine maintenance, emphasizing mathematical models (MatMs). The investigation allows the conclusion that even though the evolution of the models and methodologies is ongoing, decision making in all the areas of the wind industry is currently based on artificial intelligence and machine learning models.

scholarly journals ANALYSIS OF TECHNICAL AND ECONOMIC EFFICIENCY OF OPERATION OF THE WIND POWER PLANTS IN CRIMEA

2021 ◽  
pp. 31-41
Author(s):  
E. A. Bekirov ◽  
S. N. Voskresenskaya ◽  
V. V. Potenko
Keyword(s):  
Power Plant ◽  
Wind Power ◽  
Wind Turbines ◽  
Electricity Generation ◽  
Power Plants ◽  
Wind Farm ◽  
Net Income ◽  
Wind Power Plants ◽  
Cost Of Energy ◽  
The Cost

The article provides data on the generation and consumption of electricity by a wind farm. To maintain the operability of the wind farm, it is connected to the general grid of the power system, not only for the output of generated electricity, but also for the consumption of the necessary electricity to start the operation of wind turbines. Electricity generation, payback and net profit of a wind power plant of 12 wind turbines were estimated. Subject of study. Wind power plants and their efficiency. Materials and methods. The theoretical and methodological basis is the works of domestic and foreign scientists in the field of wind energy. In the work, analytical research methods were used, including predictive calculation of the annual energy production of wind turbines. Conclusions. The instability of electricity generation using renewable energy generating units is a serious problem that affects the cost of energy produced. According to the calculations, in 14 years, provided the electricity price is equal to 1.8 rubles, the power plant will recoup the investment and begin to generate net income. The correlation coefficient was determined, which was 0.94.

scholarly journals Coupled wind turbine design and layout optimization with nonhomogeneous wind turbines

2019 ◽  
Vol 4 (1) ◽  
pp. 99-114 ◽  
Author(s):  
Andrew P. J. Stanley ◽  
Andrew Ning
Keyword(s):  
Wind Turbines ◽  
Wind Shear ◽  
Shell Thickness ◽  
Wind Farm ◽  
Wind Farms ◽  
Layout Optimization ◽  
Structural Constraints ◽  
Cost Of Energy ◽  
The Cost ◽  
Turbine Design

Abstract. In this study, wind farms were optimized to show the benefit of coupling complete turbine design and layout optimization as well as including two different turbine designs in a fixed 1-to-1 ratio in a single wind farm. For our purposes, the variables in each turbine optimization include hub height, rotor diameter, rated power, tower diameter, tower shell thickness, and implicit blade chord-and-twist distributions. A 32-turbine wind farm and a 60-turbine wind farm were both considered, as well as a variety of turbine spacings and wind shear exponents. Structural constraints as well as turbine costs were considered in the optimization. Results indicate that coupled turbine design and layout optimization is superior to sequentially optimizing turbine design, then turbine layout. Coupled optimization results in an additional 2 %–5 % reduction in the cost of energy compared to optimizing sequentially for wind farms with turbine spacings of 8.5–11 rotor diameters. Smaller wind farms benefit even more from coupled optimization. Furthermore, wind farms with closely spaced wind turbines can greatly benefit from nonuniform turbine design throughout the farm. Some of these wind farms with heterogeneous turbine design have an additional 10 % cost-of-energy reduction compared to wind farms with identical turbines throughout the farm.

Prognosis Informed Design Framework for Operation and Maintenance of Wind Turbines

2012 ◽  
Author(s):  
Prasanna Tamilselvan ◽  
Yibin Wang ◽  
Pingfeng Wang
Keyword(s):  
Decision Making ◽  
Wind Turbines ◽  
High Performance ◽  
Wind Farm ◽  
Economic Loss ◽  
Environmental Benefits ◽  
Maintenance Strategy ◽  
System Failures ◽  
Operation And Maintenance ◽  
Failure Prognosis

Advances in high performance sensing and signal processing technology enable the development of failure prognosis tools for wind turbines to detect, diagnose, and predict the system-wide effects of failure events. Although prognostics can provide valuable information for proactive actions in preventing system failures, the benefits have not been fully utilized for the operation and maintenance decision making of wind turbines. This paper presents a generic failure prognosis informed decision making tool for wind farm operation and maintenance while considering the predictive failure information of individual turbine and its uncertainty. In the presented approach, the probabilistic damage growth model is used to characterize individual wind turbine performance degradation and failure prognostics, whereas the economic loss measured by monetary values and environmental performance measured by unified carbon credits are considered in the decision making process. Based on the customized wind farm information inputs, the developed decision making methodology can be used to identify optimum and robust strategies for wind farm operation and maintenance in order to maximize the economic and environmental benefits concurrently. The efficacy of proposed prognosis informed maintenance strategy is compared with the condition based maintenance strategy and demonstrated with the case study.

Progressive Drift of Moored Floating Wind Turbines in a Wind Farm: Improved Mooring Capacity Model

2011 ◽  
Author(s):  
Hideyuki Suzuki ◽  
Yu Kitahara ◽  
Yukinari Fukumoto
Keyword(s):  
Wind Turbine ◽  
Safety Factor ◽  
Wind Turbines ◽  
Wind Farm ◽  
Wind Farms ◽  
Floating Platform ◽  
Main Research ◽  
Electric Power Supply ◽  
Analysis And Design ◽  
Wide Range

A wide range of platform concepts have been investigated for a floating wind turbine. So far analysis and design of motion characteristics of the platform is main research concern. One key research area less focused is floating platform related risk. If the wind energy would be one of the major sources of electric power supply, wind farms which are comprised of large number of floating wind turbines must be deployed in the ocean. Wind turbines are relatively closely arranged in a wind farm. In such an arrangement, a wind turbine accidentally started drifting will have some possibility to collide with floater and moorings of neighboring moored floating wind turbines, and might initiate another drift which might cause progressive drifting of wind turbines. In the previous report, a scenario of progressive drifting of wind turbines was investigated and associated risk was formulated. Quantitative risk of several arrangements of wind farm was estimated. Effects of arrangement of wind turbines in a wind farm and safety factor used in the design of moorings is discussed. Probability of initial drift was evaluated analyzing past records of accidents and design of mooring. In this research, strength of mooring system was modeled more precisely and probabilistic model was developed considering aged deterioration. Risk of progressive drifting was evaluated and safety factor required to realize a acceptable risk of a wind farm was discussed.

Progressive Drifting of Floating Wind Turbines in a Wind Farm

2009 ◽  
Author(s):  
Hideyuki Suzuki ◽  
Masaru Kurimoto ◽  
Yu Kitahara ◽  
Yukinari Fukumoto
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farm ◽  
Wind Farms ◽  
Floating Platform ◽  
Allowable Limit ◽  
Main Research ◽  
Analysis And Design ◽  
Floating Wind Turbine ◽  
Wide Range

A wide range of platform types have been investigated for a floating wind turbine. Most of the research projects on a floating wind turbine assume that a land based wind turbine is to be installed on a platform with minimum modification to reduce the overall cost. For this reason, allowable limit of a motion of wind turbine is limited to lower value, for example, five degrees for static inclination and one to two degrees for pitching motion. So far analysis and design of motion characteristics of the platform have been main research concern. One key research area less focused is floating platform related risk. If the wind energy would be one of the major sources of power supply, wind farms which are comprised of large number of floating wind turbines must be deployed in the ocean. Wind turbines will be closely spaced in a wind farm so that installation cost should be minimized. In such an arrangement, a wind turbine accidentally started drifting has some possibility to collide or contact with the moorings of neighboring wind turbines and might cause progressive drifting of wind turbines. This paper present investigation of scenario of progressive drifting of floating wind turbines and evaluate risk of the scenario. Quantitative risk of several arrangements of wind farms is estimated. Effect of arrangement of wind turbines in a wind farm and safety factor used in design moorings is discussed.

A Levelized Cost of Energy (LCOE) Model for Wind Farms That Includes Power Purchase Agreement (PPA) Energy Delivery Limits

2016 ◽  
Author(s):  
Maira Bruck ◽  
Navid Goudarzi ◽  
Peter Sandborn
Keyword(s):  
Wind Farm ◽  
Cost Model ◽  
Wind Farms ◽  
Cost Models ◽  
Renewable Energy Resources ◽  
Supply Source ◽  
Levelized Cost ◽  
Cost Of Energy ◽  
Expected Performance ◽  
The Cost

The cost of energy is an increasingly important issue in the world as renewable energy resources are growing in demand. Performance-based energy contracts are designed to keep the price of energy as low as possible while controlling the risk for both parties (i.e., the Buyer and the Seller). Price and risk are often balanced using complex Power Purchase Agreements (PPAs). Since wind is not a constant supply source, to keep risk low, wind PPAs contain clauses that require the purchase and sale of energy to fall within reasonable limits. However, the existence of those limits also creates pressure on prices causing increases in the Levelized Cost of Energy (LCOE). Depending on the variation in capacity factor (CF), the power generator (the Seller) may find that the limitations on power purchasing given by the utility (the Buyer) are not favorable and will result in higher costs of energy than predicted. Existing cost models do not take into account energy purchase limitations or variations in energy production when calculating an LCOE. A new cost model is developed to evaluate the price of electricity from wind energy under a PPA contract. This study develops a method that an energy Seller can use to negotiate delivery penalties within their PPA. This model has been tested on a controlled wind farm and with real wind farm data. The results show that LCOE depends on the limitations on energy purchase within a PPA contract as well as the expected performance characteristics associated with wind farms.

scholarly journals Toxoplasmosis: Current and Emerging Parasite Druggable Targets

2021 ◽  
Vol 9 (12) ◽  
pp. 2531
Author(s):  
Rana El Hajj ◽  
Lina Tawk ◽  
Shaymaa Itani ◽  
Maguy Hamie ◽  
Jana Ezzeddine ◽  
...  
Keyword(s):  
Human Population ◽  
Economic Losses ◽  
Immunocompromised Patients ◽  
Parasite Resistance ◽  
Comprehensive Overview ◽  
Wide Range ◽  
Different Types ◽  
Prevalent Disease ◽  
Acute Toxoplasmosis ◽  
Druggable Targets

Toxoplasmosis is a prevalent disease affecting a wide range of hosts including approximately one-third of the human population. It is caused by the sporozoan parasite Toxoplasma gondii (T. gondii), which instigates a range of symptoms, manifesting as acute and chronic forms and varying from ocular to deleterious congenital or neuro-toxoplasmosis. Toxoplasmosis may cause serious health problems in fetuses, newborns, and immunocompromised patients. Recently, associations between toxoplasmosis and various neuropathies and different types of cancer were documented. In the veterinary sector, toxoplasmosis results in recurring abortions, leading to significant economic losses. Treatment of toxoplasmosis remains intricate and encompasses general antiparasitic and antibacterial drugs. The efficacy of these drugs is hindered by intolerance, side effects, and emergence of parasite resistance. Furthermore, all currently used drugs in the clinic target acute toxoplasmosis, with no or little effect on the chronic form. In this review, we will provide a comprehensive overview on the currently used and emergent drugs and their respective parasitic targets to combat toxoplasmosis. We will also abridge the repurposing of certain drugs, their targets, and highlight future druggable targets to enhance the therapeutic efficacy against toxoplasmosis, hence lessening its burden and potentially alleviating the complications of its associated diseases.

scholarly journals Actuator cylinder theory for multiple vertical axis wind turbines

2016 ◽  
Vol 1 (2) ◽  
pp. 327-340 ◽  
Author(s):  
Andrew Ning
Keyword(s):  
Conceptual Design ◽  
Wind Turbines ◽  
Power Loss ◽  
Wind Farm ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Navier Stokes ◽  
Vertical Axis Wind Turbines ◽  
Wide Range ◽  
Wake Interactions

Abstract. Actuator cylinder theory is an effective approach for analyzing the aerodynamic performance of vertical axis wind turbines at a conceptual design level. Existing actuator cylinder theory can analyze single turbines, but analysis of multiple turbines is often desirable because turbines may operate in near proximity within a wind farm. For vertical axis wind turbines, which tend to operate in closer proximity than do horizontal axis turbines, aerodynamic interactions may not be strictly confined to wake interactions. We modified actuator cylinder theory to permit the simultaneous solution of aerodynamic loading for any number of turbines. We also extended the theory to handle thrust coefficients outside of the momentum region and explicitly defined the additional terms needed for curved or swept blades. While the focus of this paper is a derivation of an extended methodology, an application of this theory was explored involving two turbines operating in close proximity. Comparisons were made against two-dimensional unsteady Reynolds-averaged Navier–Stokes (URANS) simulations, across a full 360° of inflow, with excellent agreement. The counter-rotating turbines produced a 5–10 % increase in power across a wide range of inflow conditions. A second comparison was made to a three-dimensional RANS simulation with a different turbine under different conditions. While only one data point was available, the agreement was reasonable, with the computational fluid dynamics (CFD) predicting a 12 % power loss, as compared to a 15 % power loss for the actuator cylinder method. This extended theory appears promising for conceptual design studies of closely spaced vertical axis wind turbines (VAWTs), but further development and validation is needed.

scholarly journals Towards the North Sea wind power revolution

2018 ◽  
Author(s):  
Jens N. Sørensen ◽  
Gunner C. Larsen
Keyword(s):  
Wind Power ◽  
North Sea ◽  
Wind Turbines ◽  
Wind Farm ◽  
Cost Model ◽  
Offshore Wind ◽  
Meteorological Model ◽  
The North ◽  
The North Sea ◽  
The Cost

Abstract. The present work assesses the potential of a massive exploitation of offshore wind power in the North Sea by combining a meteorological model with a cost model that includes a bathymetric analysis of the water depth of the North Sea. The overall objective is to assess if the wind power in the North Sea can deliver the total consumption of electricity in Europe and to what prize as compared to conventional onshore wind energy. The meteorological model is based on the assumption that the exploited area is so large, that the wind field between the turbines is in equilibrium with the atmospheric boundary layer. This makes it possible to use momentum analysis to determine the mutual influence between the atmospheric boundary layer and the wind farm, with the wind farm represented by an average horizontal force component corresponding to the thrust. The cost model includes expressions for the most essential wind farm cost elements, such as costs of wind turbines, support structures, cables and electrical substations, as well as operation and maintenance as function of rotor size, interspatial distance between the turbines, and water depth. The numbers used in the cost model are based on previous experience from offshore wind farms, and is therefore somewhat conservative. The analysis shows that the lowest energy cost is obtained for a configuration of large wind turbines erected with an interspatial distance of about eight rotor diameters. A part of the analysis is devoted to assessing the relative costs of the various elements of the cost model in order to determine the components with the largest potential for reducing the cost price. As an overall finding, it is shown that the power demand of Europe, which is 0.4 TW or about 3500 TWh/year, can be fulfilled by exploiting an area of 190.000 km2, corresponding to about 1/3 of the North Sea, with 100.000 wind turbines of generator size 13 MW on water depths up to 45 m at a cost price of about 7.5 €cents/kWh.

scholarly journals Wind Farm Layout Upgrade Optimization

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2465 ◽  
Author(s):  
Mamdouh Abdulrahman ◽  
David Wood
Keyword(s):  
Energy Production ◽  
Wind Farm ◽  
Lower Cost ◽  
Wind Farms ◽  
Offshore Wind ◽  
General Representation ◽  
Thrust Coefficient ◽  
Wind Farm Layout ◽  
Cost Of Energy ◽  
Wide Range

The problem of optimally increasing the size of existing wind farms has not been investigated in the literature. In this paper, a proposed wind farm layout upgrade by adding different (in type and/or hub height) commercial turbines to an existing farm is introduced and optimized. Three proposed upgraded layouts are considered: internal grid, external grid, and external unstructured. The manufacturer’s power curve and a general representation for thrust coefficient are used in power and wake calculations, respectively. A simple field-based model is implemented and both offshore and onshore conditions are considered. A genetic algorithm is used for the optimization. The trade-off range between energy production and cost of energy is investigated by considering three objective functions, individually: (1) annual energy production; (2) cost of added energy; and (3) cost of total energy. The proposed upgraded layouts are determined for the Horns Rev 1 offshore wind farm. The results showed a wide range of suitable upgrade scenarios depending on the upgraded layout and the optimization objective. The farm energy production is increased by 190–336% with a corresponding increase in the total cost by 147–720%. The external upgrade offers more energy production but with much more cost. The unstructured layouts showed clear superiority over the grid ones by providing much lower cost of energy.

Sign in / Sign up

Export Citation Format

Share Document