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Resource Documents: Impacts (122 items)


Also see NWW "costs/benefits" FAQ

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:  January 8, 2018
Economics, EmissionsPrint storyE-mail story

Wind and solar are much less efficient decarbonizers than combined-cycle gas turbines

Author:  Plummer, James; Frank, Charles; and Michaels, Robert


We compare three technologies that produce electricity in the United States: wind, solar, and combined-cycle gas turbines (CCGT). We use the 2016 electric utility database compiled by the U.S. Energy Information Administration (EIA). That database has the advantage of being based on a census of U.S. power plants rather than sampling, as well as excluding any subsidies received by the power plants.

We show the cost savings achieved when there is a shift between coal-fired generation and generation by wind, solar, or CCGTs, where costs include both capital and operating costs. The net cost reduction per tonne of CO₂ reduction is $4,340 for a shift from coal to wind, −$98,826 (a cost increase rather than a cost decrease) for a shift from coal to solar, and a $251,920 decrease for a shift from coal to CCGT.

When the net emissions from switching away from coal are considered, the net cost savings for each tonne of emissions avoided is $1.27 for a switch from coal to wind, −$44.11 (a net cost increase) for a switch from coal to solar, and a savings of $50.72 for a switch from coal to CCGT. The differentials between the savings from a switch to wind or solar and a switch to CCGT is a measure of the “dead weight economic loss involved in switching from coal to either form of “renewables” instead of switching from coal to CCGT.

This research concludes that CCGT is the only “economic” choice from the perspective of benefit-cost analysis.




Decarbonization cost is the differential cost of producing a MW year of electricity via coal plants and three other technologies – wind, solar, and CCGTs – divided by the differential CO₂ emissions (measured in tonnes per year).

Total net cost savings in 2016 of switching from coal to …

Tonnes of CO₂ emissions per MW-year avoided by switching from coal to …

Net cost savings per tonne of emissions avoided


Of a decision to switch from coal to wind instead of to CCGT:

Of a decision to switch from coal to solar instead of to CCGT:

Conclusion: Switching to either wind or solar instead of to CCGT involves a dead weight economic loss. However, the dead weight economic loss is twice as great for a switch to solar instead of a switch to wind.


In recent years, U.S. CO₂ emissions have been about 5.8 billion tonnes per year.

Suppose a goal of reducing those emissions by 10% or about 580 million tonnes.

As shown before, substitution of wind for coal results in a cost savings of $1.27 per tonne of CO₂ reduction, or $0.74 billion in this decarbonization scenario.

As shown before, substitution of solar for coal results in extra costs of $44.11 per tonne of CO₂ reduction, or $25.58 billion if all the investment was in solar.

However, if all the investment were done in CCGT, then the total cost savings would be $29.42 billion. So, the cost savings are larger when all the investment is in CCGT. The differences in cost savings are the amount of “dead weight economic loss” from investing in wind or solar instead of CCGTs.

These equations could be turned around to calculate, for a given fixed outlay of costs, what would be the “foregone CO₂ emissions opportunity” from investing in wind or solar instead of CCGT.


Job creation. Many of the jobs created by renewables are at the installation or capital goods production stages. The inherent capital intensivity of renewables limit their job creation potential.

Infant industry learning. This was a label invented by Argentine economist Raul Prebisch to argue for tariff protection of industry in less developed countries. However, those tariffs often led to “soft industries” that became dependent on the tariffs and did not focus on increased efficiency. A higher gain results from investing in specialized R&D activity.

Siting issues. Renewables progress over time from more favorable wind and solar sites to sites that involve higher cost per kWh produced, a classic example of “diminishing economic returns.” CCGTs are smaller physical plants, which can be sited close to natural gas supply or end-use electricity customers.


Should CCGT be eligible to receive federal tax credits analogous to the current federal tax subsidies to wind and solar? No. This would be doubling down on a bad federal policy. CCGT does not need subsidies. They can out compete wind and solar on their own.

The states mainly follow a policy of “renewables mandates” placed on regulated utilities. The utilities don’t resist these mandates very hard because the system of a fixed return on “utility rate base” largely eliminates the incentives to lower costs via investment in CCGTs. This pattern is a classic example of political “confusion of ends and means.” If the goal of electricity policy at the state level is reducing CO₂ emissions, then the state should not intervene to put CCGTs at a disadvantage.

James L. Plummer, President, Climate Economics Foundation
Charles R. Frank, Senior Non-resident Fellow, Brookings Institution
Robert R. Michaels, California State University Fullerton

[presented at the 35th United States Association for Energy Economics/International Association for Energy Economics Conference, November 12–15, 2017, Houston]

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Date added:  December 21, 2017
WildlifePrint storyE-mail story

Top 10 Myths About Wind Energy and Birds

Author:  Hutchins, Michael

Wind energy is known to many as a “green” solution to climate change. But wind energy is really just another form of industrial development, and we can’t ignore its costs and consequences to wildlife and their habitats. As Director of ABC’s Bird-Smart Wind Energy Campaign, I often encounter several common misconceptions about wind development. Read on to learn more about the real impact of unchecked wind energy development on birds and other wildlife.

Myth 1: Wind turbines are “green” energy with little or no impact on the environment.

Any form of energy production, including renewable energy, has environmental impacts. The construction of large-scale, commercial wind energy facilities takes up entire landscapes, which reduces wildlife habitat. And the maintenance roads and other support infrastructure necessary also alter habitats and affect wildlife, often in very deleterious, subtle ways. If not properly sited, operated, and regulated, renewable energy can be very harmful to wildlife and natural habitats.

Myth 2: We shouldn’t be concerned about wind energy because it doesn’t take nearly the same toll on birds as feral cats, building collisions, pesticides, and other threats.

There are two things to remember here. First, wind turbines’ impacts are far from trivial. And the impacts of all human-caused mortality are cumulative, making comparisons irrelevant and misleading.

Wind turbines and their associated infrastructure – primarily power lines and towers – are one of the fastest-growing threats to birds in the United States and Canada. At the end of 2016, there were more than 52,000 commercial-scale wind turbines operating in the United States, and tens of thousands more are currently planned or under construction. Research shows that hundreds of thousands of birds and bats die every year when they accidentally collide with the fast-spinning turbine blades. That number grows with each turbine built.

Myth 3: Power lines and towers are a separate issue.

Power lines and towers are clearly part of the equation, because they’re necessary to carry power to the grid. As a result of large-scale, commercial wind and solar development, hundreds of miles of new power lines and towers are being built to transport energy across the United States, putting birds at risk of collisions and electrocutions. The generation of energy and its transportation go hand in hand – and both present risks to wildlife. Tens of millions of birds are killed every year when they collide with towers with or are electrocuted by electrical lines.

Myth 4: The wind industry is mitigating for bird and bat deaths.

As far as birds are concerned, only two mitigation methods have been proven to be successful: building wind energy facilities away from large concentrations of birds, and slowing or stopping the movement of turbine blades (known in the industry as “curtailment”). Unfortunately, neither of these approaches is working. Turbines are going up virtually everywhere, and curtailment is unpopular with wind companies because it cuts into their profit margins.

Some companies say they use radar to detect birds and bats and then temporarily shut down a turbine’s blades. But these technologies are expensive and appear to be seldom used – and their efficacy in preventing bird and bat deaths has not been thoroughly tested.
Northern Long-eared Bat/U.S. Fish and Wildlife Service

One way to make wind turbines safe for birds and bats, such as this Northern Long-eared Bat, is to build them far from large concentrations of these animals. Photo by U.S. Fish and Wildlife Service

Myth 5: The U.S. Fish & Wildlife Service (FWS) and state wildlife agencies are regulating the wind industry to minimize its impacts on wildlife.

We have at least three federal laws designed to protect our native birds and bats from purposeful or accidental harm: the Endangered Species Act, the Migratory Bird Treaty Act, and the Bald and Golden Eagle Protection Act. Enforcement of these laws has been sporadic at best, especially with regard to the wind industry. To make matters worse, federal guidelines governing wind energy development are voluntary, not mandatory, and few developers at present are obtaining the “take” permits necessary to kill protected species.

Meanwhile, state and local regulation of the wind industry varies widely. Some states, such as Oklahoma, have virtually no regulations at all. Others, like Hawai‘i, have more-stringent policies. Wind energy has developed so rapidly that it has gotten way out ahead of the regulatory framework.

Myth 6: Wind companies conduct scientifically rigorous studies before and after new facilities are built to assess the risks wind turbines pose to birds – and are transparent in what they find.

Federal guidelines currently allow wind companies to hire consultants to prepare reports assessing a proposed facility’s risk for wildlife. It’s important to note that these are not independent, third-party scientists; they are individuals who are being paid by wind companies to do this work. Unsurprisingly, I have yet to encounter any pre-construction study that recommends moving a proposed project because of elevated risks to wildlife.

There is also the problem of hidden data. The wind industry treats information on bird and bat mortality as a proprietary trade secret. Some wind energy developers have even sued to hide these data from the public. Hawai‘i is currently the only state that requires the collection of mortality data by independent, third-party experts, and makes the information available to the public on request.

Myth 7: Offshore wind development is less destructive than onshore wind development.

There’s no indication that turbines placed in the open ocean or in the Great Lakes are any safer for birds than land-based turbines. A whole suite of different organisms could be impacted by offshore wind development and underwater cables, including migrating marine birds, waterfowl, cetaceans, fish, and other ocean-dwelling wildlife. And it’s going to be more difficult to gauge the impact: risk assessments are often based on visual observations, which can be difficult, if not impossible, during rough weather, when birds may be at highest risk. What’s more, birds that collide with the turbine blades will fall into open water and be lost.

Myth 8: We can build wind turbines in and around the Great Lakes with little or no impact on wildlife.

The best way to reduce the impacts of wind energy on birds and bats is to keep turbines away from large concentrations of these animals. Major migratory routes, stopover habitat, and key breeding or foraging areas should all be off-limits for wind development. Yet all of these are found in and around the Great Lakes, which is home to one of the world’s densest concentrations of migratory birds and bats.

Here at ABC, we oppose wind turbine construction in the Great Lakes and within at least five miles of its shorelines. We base our position on recent advanced radar studies conducted by the FWS on all five of the Great Lakes. All of the studies clearly show vast numbers of birds and bats flying over the lakes or along their shorelines, many within the rotor-swept areas of wind turbines. The FWS currently recommends that no turbines be built within three miles of the Great Lakes shorelines, while the Nature Conservancy recommends five miles. However, these are just recommendations, and some wind developers are disregarding them.

Myth 9: When it comes to combating climate change, there are no workable alternatives to industrial-scale wind energy.

There are many other ways we can address climate change besides building these huge structures in ecologically sensitive areas. We can preserve wetlands and forests to sequester carbon dioxide; we can be more energy-efficient; and we can reduce our use of fossil fuels and rely less on domestic animals (a major source of greenhouse gases) as a protein source, for starters. One of the best options is distributed solar in our already built environment – parking lots, buildings, and roads.

Myth 10: Climate change is the top threat to wildlife today; we can ignore all other threats because they pale in comparison.

Birds and other wildlife confront many threats, and they add up. One recent analysis of 8,000 species on the International Union for Conservation of Nature Red List of Threatened Species found that climate change is not the most immediate threat to wildlife today; that distinction went to the traditional threats of over-exploitation (overfishing, hunting, and so on) and habitat loss from agriculture. The authors concluded that “efforts to address climate change do not overshadow more immediate priorities for the survival of the world’s flora and fauna.”

We support wind energy development that’s done in ways that do not threaten our irreplaceable and ecologically important wildlife. To make that happen, wind energy development must be regulated more effectively. We must address climate change, to be sure – but the point is that we could be doing it so much better.

Michael Hutchins, Director of American Bird Conservancy’s Bird-Smart Wind Energy Campaign, earned his Ph.D. in animal behavior at the University of Washington. Prior to ABC, Michael was Director/William Conway Endowed Chair, Department of Conservation and Science, at the Association of Zoos and Aquariums for 15 years, and Executive Director/CEO at The Wildlife Society for seven years. He has authored over 220 articles and books on various topics in wildlife science, management, and conservation, and has traveled to over 30 countries to pursue his passion for conservation.

Originally published December 06, 2017, at abcbirds.org.

Also see ABC’s Wind Energy and Birds FAQs:
Part 1: Understanding the Threats
Part 2: Bird-Smart Wind Energy Solutions
Part 3: Take Action

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Date added:  December 9, 2017
Australia, Health, Law, NoisePrint storyE-mail story

Summary of the Effect of the Medical and Scientific Evidence

Author:  White, Richard; and Bean, Katherine

On our analysis, a number of propositions emerge from the medical and scientific evidence. Some of those propositions had unanimous support by the relevant experts, and others had the support of most.

The propositions which we understand have unanimous support from the relevant experts or are not contested include the following:

We consider that the evidence justifies the following conclusions:

Paragraphs 467–470, File Number 2015/4289
Decision and Reasons for Decision
Administrative Appeals Tribunal, Adelaide
Taxation & Commercial Division
Re Waubra Foundation (Applicant) and Commissioner of Australian Charities and Not-for-profits Commission (Respondent)

The Honourable Justice White, Deputy President
Deputy President K Bean
4 December 2017

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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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