scholarly journals Objectives and Constraints for Wind Turbine Optimization

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
S. Andrew Ning ◽  
Rick Damiani ◽  
Patrick J. Moriarty
Keyword(s):  
Wind Turbine ◽  
Energy Production ◽  
Optimization Problems ◽  
Large Fraction ◽  
High Fidelity ◽  
Variable Diameter ◽  
Cost Of Energy ◽  
Physics Modeling ◽  
The Cost ◽  
Structural Metrics

Efficient extraction of wind energy is a complex, multidisciplinary process. This paper examines common objectives used in wind turbine optimization problems. The focus is not on the specific optimized designs, but rather on understanding when certain objectives and constraints are necessary, and what their limitations are. Maximizing annual energy production, or even using sequential aero/structural optimization, is shown to be significantly suboptimal compared to using integrated aero/structural metrics. Minimizing the ratio of turbine mass to annual energy production can be effective for fixed rotor diameter designs, as long as the tower mass is estimated carefully. For variable-diameter designs, the predicted optimal diameter may be misleading. This is because the mass of the tower is a large fraction of the total turbine mass, but the cost of the tower is a much smaller fraction of overall turbine costs. Minimizing the cost of energy is a much better metric, though high fidelity in the cost modeling is as important as high fidelity in the physics modeling. Furthermore, deterministic cost of energy minimization can be inadequate, given the stochastic nature of the wind and various uncertainties associated with physical processes and model choices. Optimization in the presence of uncertainty is necessary to create robust turbine designs.

A Techno-Economic Analysis of a Proposed 1.5 MW Wind Turbine With a Hydrostatic Drive Train

2009 ◽  
Author(s):  
James R. Browning ◽  
Jon G. McGowan ◽  
James F. Manwell
Keyword(s):  
Wind Turbine ◽  
Energy Production ◽  
Capital Cost ◽  
Performance Model ◽  
Drive Train ◽  
Cost Models ◽  
Initial Capital ◽  
Cost Of Energy ◽  
The Cost ◽  
Utility Scale

Although decreases in the cost of energy from utility scale wind turbine generators has made them competitive with conventional forms of utility power generation, further reductions can increase the presence of wind energy in the global energy mix. The cost of energy from a wind turbine can be reduced by increasing the annual energy production, reducing the initial capital cost of the turbine, or doing both. In this study, the cost of energy is estimated for a theoretical 1.5 MW wind turbine utilizing a continuously variable ratio hydrostatic drive train between the rotor and the generator. The estimated cost of energy is then compared to that of a conventional wind turbine of equivalent rated power. The annual energy production is estimated for the theoretical hydrostatic turbine using an assumed wind speed distribution and a turbine power curve resulting from a steady state performance model of the turbine. The initial capital cost of the turbine is estimated using cost models developed for various components unique to the hydrostatic turbine as well as economic parameters and models developed by the National Renewable Energy Lab (NREL) for their 2004 WindPACT advanced wind turbine drive train study. The resulting cost of energy, along with various performance characteristics of interest, are presented and compared to those of the WindPACT baseline turbine intended to represent a conventional utility scale wind turbine.

scholarly journals Comparison between upwind and downwind designs of a 10 MW wind turbine rotor

2018 ◽  
Author(s):  
Pietro Bortolotti ◽  
Abinhav Kapila ◽  
Carlo L. Bottasso
Keyword(s):  
Wind Turbine ◽  
Energy Production ◽  
Turbine Rotor ◽  
Design Tool ◽  
Operating Conditions ◽  
Cost Of Energy ◽  
Potential Benefits ◽  
The Cost ◽  
Interesting Alternative ◽  
Wind Turbine Rotor

Abstract. The size of wind turbines has been steadily growing in the pursuit of a lower cost of energy by an increased wind capture. In this trend, the vast majority of wind turbine rotors has been designed based on the conventional three-bladed upwind concept. This paper aims at assessing the optimality of this configuration with respect to a three-bladed downwind design, with and without an actively controlled variable coning used to reduce the cantilever loading of the blades. A 10 MW wind turbine is used for the comparison of the various design solutions, which are obtained by an automated comprehensive aerostructural design tool. Results show that, for this turbine size, downwind rotors lead to blade mass and cost reductions of 6 % and 2 %, respectively, compared to equivalent upwind configurations. Due to a more favorable rotor attitude, the annual energy production of downwind rotors may also slightly increase in complex terrain conditions characterized by a wind upflow, leading to an overall reduction in the cost of energy. However, in more standard operating conditions, upwind rotors return the lowest cost of energy. Finally, active coning is effective in alleviating loads by reducing both blade mass and cost, but these potential benefits are negated by an increased system complexity and reduced energy production. In summary, a conventional design appears difficult to beat even at these turbine sizes, although a downwind non-aligned configuration might result in an interesting alternative.

scholarly journals Evaluation of the impact of wind farm control techniques on fatigue and ultimate loads

2020 ◽  
Author(s):  
Alessandro Croce ◽  
Stefano Cacciola ◽  
Luca Sartori ◽  
Paride De Fidelibus
Keyword(s):  
Wind Turbine ◽  
Energy Production ◽  
Wind Farm ◽  
Dynamic Responses ◽  
Control Techniques ◽  
Cost Of Energy ◽  
The Individual ◽  
The Cost ◽  
The Impact ◽  
Do So

Abstract. Wind farm control is one of the solutions recently proposed to increase the overall energy production of a wind power plant. A generic wind farm control is typically synthesized so as to optimize the energy production of the entire wind farm by reducing the detrimental effects due to wake-turbine interactions. As a matter of fact, the performance of a farm control is typically measured by looking mainly at the increase of produced power, possibly weighted with the wind Weibull and rose at a specific place, and, sometimes, by looking also at the fatigue loads. However, an aspect which is rather overlooked is the evaluation of the impact that a farm control law has on the maximum loads and on the dynamic responses under extreme conditions of the individual wind turbine. In this work, two promising wind farm controls, based respectively on Wake Redirection (WR) and Dynamic Induction Control (DIC) strategy, are evaluated at a single wind turbine level. To do so, a two-pronged analysis is performed. Firstly, the control techniques are evaluated in terms of the related impact on some specific key performance indicators (e.g. fatigue and ultimate loads, actuator duty cycle and annual energy production). Secondarily, an optimal blade redesign process, which takes into account the presence of the wind farm control, is performed with the goal of quantifying the possible modification in the structure of the blade and hence of quantifying the impact of the control on the Cost of Energy model.

scholarly journals Evaluation of the impact of active wake control techniques on ultimate loads for a 10 MW wind turbine

2022 ◽  
Vol 7 (1) ◽  
pp. 1-17
Author(s):  
Alessandro Croce ◽  
Stefano Cacciola ◽  
Luca Sartori
Keyword(s):  
Wind Turbine ◽  
Energy Production ◽  
Wind Farm ◽  
Control Techniques ◽  
Control Optimization ◽  
Cost Of Energy ◽  
The Individual ◽  
The Cost ◽  
Wind Statistics ◽  
The Impact

Abstract. Wind farm control is one of the solutions recently proposed to increase the overall energy production of a wind power plant. A generic wind farm control is typically synthesized so as to optimize the energy production of the entire wind farm by reducing the detrimental effects due to wake–turbine interactions. As a matter of fact, the performance of a farm control is typically measured by looking at the increase in the power production, properly weighted through the wind statistics. Sometimes, fatigue loads are also considered in the control optimization problem. However, an aspect which is rather overlooked in the literature on this subject is the evaluation of the impact that a farm control law has on the individual wind turbine in terms of maximum loads and dynamic response under extreme conditions. In this work, two promising wind farm controls, based on wake redirection (WR) and dynamic induction control (DIC) strategy, are evaluated at the level of a single front-row wind turbine. To do so, a two-pronged analysis is performed. Firstly, the control techniques are evaluated in terms of the related impact on some specific key performance indicators, with special emphasis on ultimate loads and maximum blade deflection. Secondarily, an optimal blade redesign process is performed with the goal of quantifying the modification in the structure of the blade entailed by a possible increase in ultimate values due to the presence of wind farm control. Such an analysis provides for an important piece of information for assessing the impact of the farm control on the cost-of-energy model.

scholarly journals A method for preliminary rotor design – Part 2: Wind turbine Optimization with Radial Independence

2021 ◽  
Vol 6 (3) ◽  
pp. 917-933 ◽  
Author(s):  
Kenneth Loenbaek ◽  
Christian Bak ◽  
Michael McWilliam
Keyword(s):  
Cost Function ◽  
Wind Turbine ◽  
Energy Production ◽  
Optimization Problems ◽  
Turbine Rotor ◽  
Global Optimum ◽  
Blade Root ◽  
Rotor Design ◽  
Global Power ◽  
Optimization Methodology

Abstract. A novel wind turbine rotor optimization methodology is presented. Using an assumption of radial independence it is possible to obtain an optimal relationship between the global power (CP) and load coefficient (CT, CFM) through the use of Karush–Kuhn–Tucker (KKT) multipliers, leaving an optimization problem that can be solved at each radial station independently. It allows solving load constraint power and annual energy production (AEP) optimization problems where the optimization variables are only the KKT multipliers (scalars), one for each of the constraints. For the paper, two constraints, namely the thrust and blade root flap moment, are used, leading to two optimization variables. Applying the optimization methodology to maximize power (P) or annual energy production (AEP) for a given thrust and blade root flap moment, but without a cost function, leads to the same overall result with the global optimum being unbounded in terms of rotor radius (R̃) with a global optimum being at R̃→∞. The increase in power and AEP is in this case ΔP=50 % and ΔAEP=70 %, with a baseline being the Betz optimum rotor. With a simple cost function and with the same setup of the problem, a power-per-cost (PpC) optimization resulted in a power-per-cost increase of ΔPpC=4.2 % with a radius increase of ΔR=7.9 % as well as a power increase of ΔP=9.1 %. This was obtained while keeping the same flap moment and reaching a lower thrust of ΔT=-3.8 %. The equivalent for AEP-per-cost (AEPpC) optimization leads to increased cost efficiency of ΔAEPpC=2.9 % with a radius increase of ΔR=17 % and an AEP increase of ΔAEP=13 %, again with the same, maximum flap moment, while the maximum thrust is −9.0 % lower than the baseline.

scholarly journals Catchment Based Aerodynamic Performance Analysis of Small Wind Turbine Using a Single Blade Concept for a Low Cost of Energy

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5838
Author(s):  
Hailay Kiros Kelele ◽  
Torbjørn Kirstian Nielsen ◽  
Lars Froyd ◽  
Mulu Bayray Kahsay
Keyword(s):  
Wind Turbine ◽  
Energy Production ◽  
Low Cost ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Design Parameters ◽  
Wind Condition ◽  
Small Wind Turbine ◽  
Cost Of Energy ◽  
Wind Potential

For low and medium wind conditions, there is a possibility to harness maximum wind potential reducing the cost of energy by employing catchment-based wind turbine designs. This paper aims to study catchment-based small wind turbine aerodynamic performance for improved efficiency and reduced cost of energy. Hence, design parameters are considered based on specific conditions within a catchment area. The bins and statistical methods implemented with Weibull distribution of wind data for selected sites to characterize the wind conditions and a weighted average method proposed to create representative wind conditions implementing a single blade concept. The blade element method was applied using Matlab code (version R2017a, MathWorks Inc., Natick, MA, US) for aerodynamic design and analysis, and computational fluid dynamics employed using ANSYS—Fluent (version 18.1, ANSYS Inc., Canonsburg, PA, USA) for validation. The performance of the designed blade is evaluated based on annual energy production, capacity factor and power coefficient. Then, for site-specific wind conditions, yearly energy production, and relative cost of energy are examined against rated power. Appropriate rated power for a low cost of energy identified and performance measures evaluated for each site. As a result, a maximum power coefficient of around 51.8% achieved at a design wind speed of 10 m/s, and higher capacity factors of 28% and 50.9% respectively attained for the low and high wind conditions at the proposed rated powers. Therefore, for different wind condition sites, enhanced performance at a low cost of energy could be achieved using a single blade concept at properly selected rated powers employing suitable design conditions and procedures.

scholarly journals Potential of wind energy resources around Nasawana village in Nabouwalu, Vanua Levu, Fiji

2020 ◽  
pp. 014459872097067
Author(s):  
Krishnam Nair ◽  
Ajal Kumar
Keyword(s):  
Energy Demand ◽  
Energy Production ◽  
Fossil Fuel ◽  
Solar Pv ◽  
Cost Of Energy ◽  
Wind Analysis ◽  
The Pacific ◽  
The Cost ◽  
Wind Resource ◽  
Wind Energy Resources

Fiji is located in the South Western part of the Pacific between latitude 18° S and longitude 179° E. In 2018, Fiji has spent approximately FJD 800 million in importing fossil fuel to meet the rising energy demand in the country. In the previous year’s several solar PV and wind resource assessments has been done and results obtained indicated that there is a potential for grid connected electricity generation using recommended resources. This study was carried out in the Nasawana Village (16°55.3 S and 178°47.4 E) to determine the options to use electricity derived from the wind. Wind analysis was carried out using Wind Atlas Analysis and Application Program (WAsP) that predicted the wind speed of 6.96 ms−1 and a power density of 256 Wm−2 at 55 m a.g.l. The annual energy production predicted for a single wind turbine (Vergnet 275 kW) is approximately 631.6 MWh with a capacity factor of 26%. The cost of energy per kWh is estimated as FJD 0.10 with a payback period of 7 years.

A Comparative Cost Analysis of Floating Wind Turbine Platforms

2013 ◽  
Author(s):  
Daniel A. Dwyer ◽  
Justin C. Emmerik
Keyword(s):  
Wind Turbine ◽  
Energy Production ◽  
Sensitivity Study ◽  
Operating Parameters ◽  
Floating Wind Turbine ◽  
Cost Of Energy ◽  
Wide Range ◽  
Anchoring System ◽  
Steel Weight ◽  
Cost Factors

This thesis presents a cost-of-energy (COE) analysis comparing three types of floating wind turbine platforms—spar-buoy, semi-submersible, and tension-leg platform (TLP)— based on existing commercial designs. The analysis develops the COE of a 500-MW reference wind plant at a reference offshore location using a merit-based criterion that integrates both lifecycle cost and turbine energy production. A sensitivity study examines how fluctuations in site-dependent operating parameters and fabrication cost factors affect results. The analysis demonstrates that while the COE of a floating wind plant can vary across a wide range ($0.10 to $0.22/kWh), the relative COE performance of the three platforms does not change. The TLP consistently enables the lowest COE across a range of operating parameters as a result of its comparatively low steel weight and less expensive mooring and anchoring system. The percent differences between the COE enabled by the TLP and that of the spar-buoy and semi-submersible are 4% and 19%, respectively, at the baseline reference site.

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