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Resource Documents: Technology (130 items)

RSSTechnology

Also see NWW "technology" and "size" FAQs

Documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are provided to assist anyone wishing to research the issue of industrial wind power and the impacts of its development. The information should be evaluated by each reader to come to their own conclusions about the many areas of debate.


Date added:  May 1, 2018
Emissions, TechnologyPrint storyE-mail story

Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems

Author:  Heard, Ben; Brook, Barry; Wigley, Tom; and Bradshaw, Corey

ABSTRACT. An effective response to climate change demands rapid replacement of fossil carbon energy sources. This must occur concurrently with an ongoing rise in total global energy consumption. While many modelled scenarios have been published claiming to show that a 100% renewable electricity system is achievable, there is no empirical or historical evidence that demonstrates that such systems are in fact feasible. Of the studies published to date, 24 have forecast regional, national or global energy requirements at sufficient detail to be considered potentially credible. We critically review these studies using four novel feasibility criteria for reliable electricity systems needed to meet electricity demand this century. These criteria are: (1) consistency with mainstream energy-demand forecasts; (2) simulating supply to meet demand reliably at hourly, half-hourly, and five-minute timescales, with resilience to extreme climate events; (3) identifying necessary transmission and distribution requirements; and (4) maintaining the provision of essential ancillary services. Evaluated against these objective criteria, none of the 24 studies provides convincing evidence that these basic feasibility criteria can be met. Of a maximum possible unweighted feasibility score of seven, the highest score for any one study was four. Eight of 24 scenarios (33%) provided no form of system simulation. Twelve (50%) relied on unrealistic forecasts of energy demand. While four studies (17%; all regional) articulated transmission requirements, only two scenarios—drawn from the same study—addressed ancillary-service requirements. In addition to feasibility issues, the heavy reliance on exploitation of hydroelectricity and biomass raises concerns regarding environmental sustainability and social justice. Strong empirical evidence of feasibility must be demonstrated for any study that attempts to construct or model a low-carbon energy future based on any combination of low-carbon technology. On the basis of this review, efforts to date seem to have substantially underestimated the challenge and delayed the identification and implementation of effective and comprehensive decarbonization pathways.

B.P. Heard, University of Adelaide, South Australia, Australia
B.W. Brook, University of Tasmania, Australia
T.M.L. Wigley, National Center for Atmospheric Research, Boulder, Colorado, USA
C.J.A. Bradshaw, Flinders University, South Australia, Australia

Renewable and Sustainable Energy Reviews 76 (2017) 1122–1133.
doi: 10.1016/j.rser.2017.03.114

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Date added:  March 13, 2018
Sweden, TechnologyPrint storyE-mail story

Wind turbine performance decline in Sweden

Author:  Olauson, Jon; Edström, Per; and Rydén, Jesper

[Abstract] We show that Swedish wind turbines constructed before 2007 lose 0.15 capacity factor percentage points per year, corresponding to a lifetime energy loss of 6%. A gradual increase of downtime accounts for around one third of the deterioration and worsened efficiency for the remaining. Although the performance loss in Sweden is considerably smaller than previously reported in the UK, it is statistically significant and calls for a revision of the industry practice for wind energy calculations. The study is based on two partly overlapping datasets, comprising 1,100 monthly and 1,300 hourly time series spanning 5–25 years each.

Jon Olauson, Division of Electricity, Department of Engineering Sciences, Uppsala University, Uppsala, Sweden
Per Edström, Sweco Energuide, Gothenburg, Sweden
Jesper Rydén, Department of Mathematics, Uppsala University, Uppsala, Sweden

Wind Energy 2017; 20(12):2049–2053. DOI: 10.1002/we.2132

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Date added:  March 10, 2018
Grid, TechnologyPrint storyE-mail story

Effect of Energy Storage on Variations in Wind Power

Author:  Paatero, Jukka; and Lund, Peter

[abstract] Irregularities in power output are characteristic of intermittent energy, sources such as wind energy, affecting both the power quality and planning of the energy system. In this work the effects of energy storage to reduce wind power fluctuations are investigated. Integration of the energy storage with wind power is modelled using a filter approach in which a time constant corresponds to the energy storage capacity.The analyses show that already a relatively small energy storage capacity of 3 kWh (storage) per MW wind would reduce the short-term power fluctuations of an individual wind turbine by 10%. Smoothing out the power fluctuation of the wind turbine on a yearly level would necessitate large storage, e.g. a 10% reduction requires 2–3 MWh per MW wind.

Jukka V. Paatero and Peter D. Lund
Helsinki University of Technology, Advanced Energy Systems, Espoo, Finland

Wind Energy 2005; 8:421–441. DOI: 10.1002/we.151

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Date added:  December 5, 2017
Noise, TechnologyPrint storyE-mail story

Consistent modelling of wind turbine noise propagation from source to receiver

Author:  Barlas, Emre; et al.

Abstract —
The unsteady nature of wind turbine noise is a major reason for annoyance. The variation of far-field sound pressure levels is not only caused by the continuous change in wind turbine noise source levels but also by the unsteady flow field and the ground characteristics between the turbine and receiver. To take these phenomena into account, a consistent numerical technique that models the sound propagation from the source to receiver is developed. Large eddy simulation with an actuator line technique is employed for the flow modelling and the corresponding flow fields are used to simulate sound generation and propagation. The local blade relative velocity, angle of attack, and turbulence characteristics are input to the sound generation model. Time-dependent blade locations and the velocity between the noise source and receiver are considered within a quasi-3D propagation model. Long-range noise propagation of a 5 MW wind turbine is investigated. Sound pressure level time series evaluated at the source time are studied for varying wind speeds, surface roughness, and ground impedances within a 2000 m radius from the turbine.

Emre Barlas, Wen Zhong Shen, and Kaya O. Dag
— Department of Wind Energy, Technical University of Denmark, Kongens Lyngby, Denmark
Wei Jun Zhu – School of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou, China
Patrick Moriarty – National Wind Technology Center, National Renewable Energy Laboratory, Boulder, Colorado, USA

The Journal of the Acoustical Society of America 2017 Nov;142(5):3297.
doi: 10.1121/1.5012747.

Download original document: “Consistent modelling of wind turbine noise propagation from source to receiver

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