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Unless indicated otherwise, documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are shared here 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. • The copyrights reside with the sources indicated. As part of its noncommercial effort to present the environmental, social, scientific, and economic issues of large-scale wind power development to a global audience seeking such information, National Wind Watch endeavors to observe “fair use” as provided for in section 107 of U.S. Copyright Law and similar “fair dealing” provisions of the copyright laws of other nations.

Date added:  July 21, 2021
Scotland, WildlifePrint storyE-mail story

Responses of dispersing GPS-tagged Golden Eagles (Aquila chrysaetos) to multiple wind farms across Scotland

Abstract: Wind farms may have two broad potential adverse effects on birds via antagonistic processes: displacement from the vicinity of turbines (avoidance), or death through collision with rotating turbine blades. Large raptors are often shown or presumed to be vulnerable to collision and are demographically sensitive to additional mortality, as exemplified by several studies of the Golden Eagle Aquila chrysaetos. Previous findings from Scottish Eagles, however, have suggested avoidance as the primary response. Our study used data from 59 GPS-tagged Golden Eagles with 28 284 records during natal dispersal before and after turbine operation &ly; 1 km of 569 turbines at 80 wind farms across Scotland. We tested three hypotheses using measurements of tag records’ distance from the hub of turbine locations: (1) avoidance should be evident; (2) older birds should show less avoidance (i.e. habituate to turbines); and (3) rotor diameter should have no influence (smaller diameters are correlated with a turbine’s age, in examining possible habituation). Four generalized linear mixed models (GLMMs) were constructed with intrinsic habitat preference of a turbine location using Golden Eagle Topography (GET) model, turbine operation status (before/after), bird age and rotor diameter as fixed factors. The best GLMM was subsequently verified by k-fold cross-validation and involved only GET habitat preference and presence of an operational turbine. Eagles were eight times less likely to be within a rotor diameter’s distance of a hub location after turbine operation, and modelled displacement distance was 70 m. Our first hypothesis expecting avoidance was supported. Eagles were closer to turbine locations in preferred habitat but at greater distances after turbine operation. Results on bird age (no influence to 5+ years) rejected hypothesis 2, implying no habituation. Support for hypothesis 3 (no influence of rotor diameter) also tentatively inferred no habituation, but data indicated birds went slightly closer to longer rotor blades although not to the turbine tower. We proffer that understanding why avoidance or collision in large raptors may occur can be conceptually envisaged via variation in fear of humans as the ‘super predator’ with turbines as cues to this life-threatening agent.

Alan H. Fielding, Natural Research Ltd, Brathens, Aberdeenshire
David Anderson, Forestry and Land Scotland, Aberfoyle
Stuart Benn, RSPB Scotland, Inverness
Roy Dennis, Roy Dennis Wildlife Foundation, Forres
Matthew Geary, Department of Biological Sciences, University of Chester
Ewan Weston, Natural Research Ltd, Brathens, Aberdeenshire
D. Philip Whitfield, Natural Research Ltd, Brathens, Aberdeenshire

Ibis: International Journal of Avian Science
Published on line ahead of print 20 July 2021. doi: 10.1111/ibi.12996

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Date added:  July 15, 2021
TechnologyPrint storyE-mail story

Leading edge erosion of wind turbine blades: a sampling of research

Author:  Various

Water droplet erosion of wind turbine blades: mechanics, testing, modeling and future perspectives

Mohamed Elhadi Ibrahim and Mamoun Medraj
Department of Mechanical and Industrial Engineering, Concordia University, Montréal, Québec, Canada

[Abstract] The problem of erosion due to water droplet impact has been a major concern for several industries for a very long time and it keeps reinventing itself wherever a component rotates or moves at high speed in a hydrometer environment. Recently, and as larger wind turbine blades are used,erosion of the leading edge due to rain droplets impact has become a serious issue. Leading-edge erosion causes a significant loss in aerodynamics efficiency of turbine blades leading to a considerable reduction in annual energy production. This paper reviews the topic of water droplet impact erosion as it emerges in wind turbine blades. …

Materials 2020;13:157. doi:10.3390/ma1301015. Download.

A probabilistic long-term framework for site-specific erosion analysis of wind turbine blades: a case study of 31 Dutch sites

Amrit Shankar Verma, Zhiyu Jiang, Zhengru Ren, Marco Caboni, Hans Verhoef, Harald van der Mijle-Meijer, Saullo G.P. Castro, and Julie J.E. Teuwen
Faculty of Aerospace Engineering, University of Technology, Delft, The Netherlands; Department of Ships and Ocean Structures, SINTEF Ocean, Trondheim, Norway; Department of Engineering Sciences, University of Agder, Grimstad, Norway; Department of Marine Technology, Norwegian University of Science and Technology, Trondheim, Norway; TNO Energy Transition, Petten, The Netherlands

[Abstract] Rain-induced leading-edge erosion (LEE) of wind turbine blades (WTBs) is associated with high repair and maintenance costs. The effects of LEE can be triggered in less than 1 to 2 years for some wind turbine sites, whereas it may take several years for others. In addition, the growth of erosion may also differ for different blades and turbines operating at the same site. Hence, LEE is a site- and turbine-specific problem. In this paper, we propose a probabilistic long-term framework for assessing site- specific lifetime of a WTB coating system. Case studies are presented for 1.5 and 10 MW wind turbines, where geographic bubble charts for the leading-edge lifetime and number of repairs expected over the blade’s service life are established for 31 sites in the Netherlands. The proposed framework efficiently captures the effects of spatial and orographic features of the sites and wind turbine specifications on LEE calculations. For instance, the erosion is highest at the coastal sites and for sites located at higher altitudes. In addition, erosion is faster for turbines associated with higher tip speeds, and the effects are critical for such sites where the exceedance probability for rated wind conditions are high. …

Wind Energy 2021 [published online March 26]. doi:10.1002/we.2634. Download.

RADAR-derived precipitation climatology for wind turbine blade leading edge erosion

Frederick Letson, Rebecca J. Barthelmie, and Sara C. Pryor
Department of Earth and Atmospheric Sciences and Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York

[Abstract] Wind turbine blade leading edge erosion (LEE) is a potentially significant source of revenue loss for windfarm operators. Thus, it is important to advance understanding of the underlying causes, to generate geospatial estimates of erosion potential to provide guidance in pre-deployment planning and ultimately to advance methods to mitigate this effect and extend blade lifetimes. This study focuses on the second issue and presents a novel approach to characterizing the erosion potential across the contiguous USA based solely on publicly available data products from the National Weather Service dual-polarization RADAR. The approach is described in detail and illustrated using six locations distributed across parts of the USA that have substantial wind turbine deployments. Results from these locations demonstrate the high spatial variability in precipitation-induced erosion potential, illustrate the importance of low probability high impact events to cumulative annual total kinetic energy transfer and emphasize the importance of hail as a damage vector.

Wind Energy Science 2019 [published online August 13]. doi:10.5194/wes-2019-43. Download

Rain erosion maps for wind turbines based on geographical locations: a case study in Ireland and Britain

Kieran Pugh and Margaret Stack
Department of Mechanical Engineering, University of Strathclyde, Glasgow, Scotland

[Abstract] Erosion rates of wind turbine blades are not constant, and they depend on many external factors including meteorological differences relating to global weather patterns. In order to track the degradation of the turbine blades, it is important to analyse the distribution and change in weather conditions across the country. This case study addresses rainfall in Western Europe using the UK and Ireland data to create a relationship between the erosion rate of wind turbine blades and rainfall for both countries. …

[Introduction] … One common advance is to install much larger blades, however, this is coupled with substantially greater tip velocities of the blades. These increased velocities create a higher risk of degradation of the leading edge due to impacts from rain erosion. With tip speeds from turbines reaching 300mph, the repeated impact of raindrops is sufficiently energetic to erode the material. The erosion rates of wind turbines have a direct relationship to the environment they are erected. More rainfall will result in more erosion of turbine blades. Typically wind turbine farms are constructed in barren locations due to land availability, wind speeds and away from local beauty spots; however, this results in turbines being subjected to harsh conditions and in some locations heavy rainfall. …

Journal of Bio- and Tribo-Corrosion 2021;7:34. doi:10.1007/s40735-021-00472-0. Download.

Mapping hail meteorological observations for prediction of erosion in wind turbines

Hamish Macdonald, David Infield, David H. Nash, and Margaret M. Stack
Wind Energy Systems CDT and Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow, Scotland

[Abstract] Wind turbines can be subject to a wide range of environmental conditions during a life span that could conceivably extend beyond 20 years. Hailstone impact is thought to be a key factor in the leading edge erosion and damage of the composite materials of wind turbine blades. Using UK meteorological data, this paper demonstrates that the rotational speed is a crucial factor in determining the magnitude of the kinetic energy associated with singular impact and is likely to be significant for incidents of hail. …

Wind Energy 2016;19:777. doi:10.1002/we.1854. Download.

Forurensing fra vindturbinvinger

[Leading edge erosion and pollution from wind turbine blades]
Asbjørn Solberg, Bård-Einar Rimereit, and Jan Erik Weinbach
The Turbine Group, Stavanger, Sogndal, and Trondheim, April 22, 2021 [in Norwegian]. Download.

[Foreword] We have put together a report on an undercommunicated topic: microplastic emissions and possible toxic compounds in them. … Already in 2013, rotor blades for wind turbines accounted for 27% of Europe’s consumption of fiberglass-reinforced epoxy. Depending on the production method for the rotor blades, the epoxy contains as much as ~33% bisphenol A. … Bisphenol A is on the «Norwegian priority list of dangerous substances». (Vi har satt samme en rapport om et underkommunisert tema; utslipp av mikroplast og mulige giftige forbindelser i disse. Allerede i 2013 utgjorde rotorblad til vindkraftverk 27 % av Europas forbruk av glassfiberarmert epoksy. Avhengig av produksjonsmetode for rotorbladene så inneholder epoksyen så mye som ca. 33 % Bisfenol A. Bisfenol A står på «Den norske prioritetslista over farlige stoff».)

English version, July 8, 2021: doi:10.13140/RG.2.2.33339.34080 [download]

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Date added:  July 4, 2021
California, Economics, New Mexico, Technology, Texas, U.S.Print storyE-mail story

How Green Mandates Are Undermining the Affordability and Reliability of Electricity

Author:  Power the Future

On Earth Day, President Biden pledged under the Paris Climate Agreement that the United States would reduce greenhouse gas emissions by 50 percent in ten years (below 2005 levels). This goal is as preposterous as it is impractical. It’s clear that the Biden Administration is misleading the American people to impose the Green Agenda which includes stifling bureaucratic manipulation in every sector of the economy. Power The Future’s latest study, “Lights Out: How Green Mandates Are Undermining the Affordability and Reliability of Electricity,” explores the real costs and benefits of Biden’s plan.

Biden’s Climate Envoy John Kerry has himself admitted: “Almost 90 percent of all of the planet’s global emissions come from outside of U.S. borders. We could go to zero tomorrow and the problem isn’t solved.”

On this, as in little else, Kerry is right: Even assuming every signatory to the Paris Agreement (the US included, as pledged under President Obama) fulfilled its emissions commitments, the climate impact “is minuscule.” In measuring the temperature impact of every nation fulfilling every promise by 2030, the total temperature reduction would be 0.048°C (0.086°F) by 2100. Carry those assumptions out another 70 years, and Paris would reduce temperatures by just 0.17°C by 2100.

So what can we realistically expect from the types of proposals Biden is pushing? PTF looked at the results of renewable mandates in Texas, California, and New Mexico to find out.

Based on data from those states, it is clear that Biden’s pledge under the Paris Agreement sets the country on a dangerous trajectory. Green radicals will use it to push their fever dream of a 100 percent “clean” grid, powered by sources that don’t work at night or on cloudy days. These policies destroy good-paying jobs and raise energy prices. It’s time to wake up to these realities with policies that promote fuel diversity, reliability, and affordability—before it’s too late for all of us.

Download original document: “How Green Mandates Are Undermining the Affordability and Reliability of Electricity

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Date added:  June 29, 2021
EnvironmentPrint storyE-mail story

Coastal and offshore based wind power may be a significant contributor of micro and nano sized particles containing BPA and other harmful chemicals to the environment through leading edge erosion

Author:  Green Warriors of Norway (Norges Miljøvernforbund)

Green Warriors of Norway/Norges Miljøvernforbund (NMF) raise several concerns regarding the increased use of Bisphenol A (BPA) and related chemicals and their impact on onshore and offshore environment and ecosystems. Much of the current and future impact will come from relatively new sources, and from sources that will increase in new areas and environments. One of the main sources of concern is from micro and nano sized particles released into the environment from epoxy-based products by erosion. Such particles that contain BPA related substances will protect its containing chemicals and protect them from degradation while they remain inside the particle materials, and like a Trojan Horse, be released into the food chain through organisms when in contact with their digestive system. It is also concerning that research show that BPA do generational harm to organisms according to a recent study of Rainbow trout.

These factors and more raise serious concerns as the development and placement of new installations reliant upon BPA containing epoxy structures reaches new frontiers with harsher and more challenging weather conditions. While chemicals like BPA in its pure form is degraded normally in a normal environment, salt water and colder temperatures in more arctic and sub-arctic environments will likely impact the rate of degradation significantly, which make them remain a potent biochemical pollutant for a much longer period than in more tempered environments. Within the protection of a micro-sized particle, they will remain a potent biochemical pollutant significantly longer than the chemical in its pure form.

With micro and nano sized particles found in larger and larger quantities on the farthest parts of the planet, from the furthest away glaciers to sediments on the deepest seabed, the concern is that our human impact on the various onshore and offshore environments accumulate and is irreversible.

We therefore need much stricter regulations and also serious incentives for the industry to find better alternatives and in the meantime stop the placement of new installations that release micro and nano sized particles containing BPA and similar chemicals to the environment.

You will find our concerns and demands in more detail on the following pages.

Download original document: “Bisphenol A: comments and evidence re: Registration, Evaluation, Authorisation and Restriction of Chemicals, European Chemicals Agency

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