scholarly journals USA Wind Energy-Caused Bat Fatalities Increase with Shorter Fatality Search Intervals

Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 98
Author(s):  
K. Shawn Smallwood

Wind turbine collision fatalities of bats have likely increased with the rapid expansion of installed wind energy capacity in the USA since the last national-level fatality estimates were generated in 2012. An assumed linear increase of fatalities with installed capacity would expand my estimate of bat fatalities across the USA from 0.89 million in 2012 to 1.11 million in 2014 and to 1.72 million in 2019. However, this assumed linear relationship could have been invalidated by shifts in turbine size, tower height, fatality search interval during monitoring, and regional variation in bat fatalities. I tested for effects of these factors in fatality monitoring reports through 2014. I found no significant relationship between bat fatality rates and wind turbine size. Bat fatality rates increased with increasing tower height, but this increase mirrored the increase in fatality rates with shortened fatality search intervals that accompanied the increase in tower heights. Regional weighting of mean project-level bat fatalities increased the national-level estimate 17% to 1.3 (95% CI: 0.15–3.0) million. After I restricted the estimate’s basis to project-level fatality rates that were estimated from fatality search intervals <10 days, my estimate increased by another 71% to 2.22 (95% CI: 1.77–2.72) million bat fatalities in the USA’s lower 48 states in 2014. Project-level fatality estimates based on search intervals <10 days were, on average, eight times higher than estimates based on longer search intervals. Shorter search intervals detected more small-bodied species, which contributed to a larger all-bat fatality estimate.

2021 ◽  
Vol 11 (22) ◽  
pp. 11043
Author(s):  
Urs Giger ◽  
Stefan Kleinhansl ◽  
Horst Schulte

New locations for onshore technology, which have not been considered so far, must be developed to increase the total installed capacity of renewable energies, especially wind energy. For this purpose, cost-effective wind turbines, even in difficult-to-access locations, such as mountainous and high-mountainous areas, must be designed. This paper presents a novel wind turbine with a related control system that meets these requirements. The proposed turbine uses a multi-rotor configuration with five rotors arranged in a star shape configuration. Each rotor drive train combines up to 12 generators in a maintenance-friendly multi-generator concept. A suitable observer-based control for load mitigation in the full-load region is proposed for the multi-rotor and multi-generator design. Simulations are used to demonstrate the applicability and practical benefits of this concept.


Author(s):  
Evgenii Ignatev ◽  
Galina Deryugina ◽  
Htet Myat Htoon ◽  
Mikhail Tyagunov

One of Myanmar's problems is energy shortage. Partially, energy shortage can possibly be decreased by the construction of sizeable grid-connected offshore wind farms. Eight prospective construction sites were selected and wind turbine models chosen. This chapter describes the method for determining the optimal composition of the wind farms complex, consisting of several offshore wind farms located at a considerable distance from each other in areas with significant wind regime asynchrony. To illustrate this method, the optimal composition with an installed capacity of 47.6 MW and located off Myanmar's west coast is defined.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6325
Author(s):  
Nafsika Stavridou ◽  
Efthymios Koltsakis ◽  
Charalampos C. Baniotopoulos

Renewable energy is expected to experience epic growth in the coming decade, which is reflected in the record new installations since 2010. Wind energy, in particular, has proved its leading role among sustainable energy production means, by the accelerating rise in total installed capacity and by its consistently increasing trend. Taking a closer look at the history of wind power development, it is obvious that it has always been a matter of engineering taller turbines with longer blades. An increase in the tower height means an increase in the material used, thereby, impacting the initial construction cost and the total energy consumed. In the present study, a numerical investigation is carried out in order to actively compare conventional cylindrical shell towers with lattice towers in terms of material use, robustness and environmental impact. Lattice structures are proved to be equivalently competitive to conventional cylindrical solutions since they can be designed to be robust enough while being a much lighter tower in terms of material use. With detailed design, lattice wind turbine towers can constitute the new generation of wind turbine towers.


Climate ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 136
Author(s):  
Rebecca J. Barthelmie ◽  
Sara C. Pryor

Global wind resources greatly exceed current electricity demand and the levelized cost of energy from wind turbines has shown precipitous declines. Accordingly, the installed capacity of wind turbines grew at an annualized rate of about 14% during the last two decades and wind turbines now provide ~6–7% of the global electricity supply. This renewable electricity generation source is thus already playing a role in reducing greenhouse gas emissions from the energy sector. Here we document trends within the industry, examine projections of future installed capacity increases and compute the associated climate change mitigation potential at the global and regional levels. Key countries (the USA, UK and China) and regions (e.g., EU27) have developed ambitious plans to expand wind energy penetration as core aspects of their net-zero emissions strategies. The projected climate change mitigation from wind energy by 2100 ranges from 0.3–0.8 °C depending on the precise socio-economic pathway and wind energy expansion scenario followed. The rapid expansion of annual increments to wind energy installed capacity by approximately two times current rates can greatly delay the passing of the 2 °C warming threshold relative to pre-industrial levels. To achieve the required expansion of this cost-effective, low-carbon energy source, there is a need for electrification of the energy system and for expansion of manufacturing and installation capacity.


2010 ◽  
Vol 28 (5) ◽  
pp. 1043-1052 ◽  
Author(s):  
R. J. Barthelmie ◽  
A. M. Sempreviva ◽  
S. C. Pryor

Abstract. Wind energy developments offshore focus on larger turbines to keep the relative cost of the foundation per MW of installed capacity low. Hence typical wind turbine hub-heights are extending to 100 m and potentially beyond. However, measurements to these heights are not usually available, requiring extrapolation from lower measurements. With humid conditions and low mechanical turbulence offshore, deviations from the traditional logarithmic wind speed profile become significant and stability corrections are required. This research focuses on quantifying the effect of humidity fluxes on stability corrected wind speed profiles. The effect on wind speed profiles is found to be important in stable conditions where including humidity fluxes forces conditions towards neutral. Our results show that excluding humidity fluxes leads to average predicted wind speeds at 150 m from 10 m which are up to 4% higher than if humidity fluxes are included, and the results are not very sensitive to the method selected to estimate humidity fluxes.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5167
Author(s):  
Jordi Cusidó ◽  
Arnau López ◽  
Mattia Beretta

Wind energy is a form of renewable energy with the highest installed capacity. However, it is necessary to reduce the operation and maintenance costs and extend the lifetime of wind turbines to make wind energy more competitive. This paper presents a power-derating-based Fault-Tolerant Control (FTC) model in 2 MW three-bladed wind turbines implemented using the National Renewable Energy Laboratory’s (NREL) Fatigue, Aerodynamics, Structures, and Turbulence (FAST) wind turbine simulator. This control strategy is potentially supported by the health status of the gearbox, which was predicted by means of algorithms and quantified in an indicator denominated as a merge developed by SMARTIVE, a pioneering of in this idea. Fuzzy logic was employed in order to decide whether to down-regulate the output power or not, and to which level to adjust to the needs of the turbines. Simulation results demonstrated that a reduction in the power output resulted in a safer operation, since the stresses withstood by the blades and tower significantly decreased. Moreover, the results supported empirically that a diminution in the generator torque and speed was acheived, resulting in a drop in the gearbox bearing and oil temperatures. By implementing this power-derating FTC, the downtime due to failure stops could be controlled, and thus the power production noticeably grew. It has been estimated that more than 325,000 tons of CO2 could be avoided yearly if implemented globally.


Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.


Author(s):  
J. V. Muruga Lal Jeyan ◽  
Akhila Rupesh ◽  
Jency Lal

The aerodynamic module combines the three-dimensional nonlinear lifting surface theory approach, which provides the effective propagated incident velocity and angle of attack at the blade section separately, and a two-dimensional panel method for steady axisymmetric and non-symmetric flow has to be involved to obtain the 3D pressure and velocity distribution on the wind mill model blade. Wind mill and turbines have become an economically competitive form of efficiency and renewable work generation. In the abroad analytical studies, the wind turbine blades to be the target of technological improvements by the use of highly possible systematic , aerodynamic and design, material analysis, fabrication and testing. Wind energy is a peculiar form of reduced form of density source of power. To make wind power feasible, it is important to optimize the efficiency of converting wind energy into productivity source. Among the different aspects involved, rotor aerodynamics is a key determinant for achieving this goal. There is a tradeoff between thin airfoil and structural efficiency. Both of which have a strong impact on the cost of work generated. Hence the design and analysis process for optimum design requires determining the load factor, pressure and velocity impact and optimum thickness distribution by finding the effect of blade shape by varying thickness on the basis of both the aerodynamic output and the structural weight.


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