While Maine has a host of stubborn challenges — high taxes, costly health care and cold weather, to name a few — there is one issue where policy makers can make a large difference in the months ahead: how to reduce the exorbitant price of electric power. In this two-part series we look at how Maine’s policies on electric power, taxation and economic development presently intersect and how those policies must change to benefit from wind. …

In the same fashion that our nation has failed in recent decades to maintain its highways, its bridges, its rail lines, its flood levees and its water and sewer systems, it has also failed to keep pace with our growing dependence on electricity.

It is not so much a shortage of generators that renders our systems so vulnerable but our inability to dispatch available power quickly to places where it is needed. As the 2003 blackout cascaded across Ohio, Michigan, Pennsylvania, New Jersey and Ontario, the state of New York still had generators in reserve but was unable to deploy them in time to save even itself, let alone its neighboring states.

As the demand for electric power has steadily grown, investors have built generators and transmission lines to keep pace, but utilities have failed to provide the responsive control systems necessary to manage power effectively. …

Long before the blackout of 2003, Washington had been gridlocked over energy. But the “Final Report on the August 14, 2003, Blackout in the U.S. and Canada” finally goaded Congress into passing The Energy Policy Act of 2005, a lengthy and comprehensive law that shifts energy policy on many fronts.

On the specific topic of electricity, the law emphasizes reliability to the exclusion of every other competing value — including cost, the environment or local autonomy. Reliability standards that were once voluntary are now mandatory. Utilities that fail to comply are now to be penalized.

In addition, the Federal Energy Regulatory Commission (FERC) has authority to reward handsomely — at the expense of ratepayers — any utility that seeks to build new transmission lines needed to improve the grid. If state regulators get in the way, the federal Department of Energy may override local resistance by designating a geographic area as a “national interest electric transmission corridor”.

Reliability in New England

Although all of eastern North America is essentially a single organic grid with high levels of interdependency among regions, there are “seams” in the network defining smaller management areas. One of those seams surrounds the six New England states and is managed by “ISO-NE” — the Independent System Operator for New England, a non-profit organization that coordinates reliability for the region. Its annual administrative cost to ratepayers is $125M. ISO-NE contracts with most of New England’s utilities to dispatch power, set transmission tariffs and operate a market for the sale of wholesale electricity.

When the blackout wave surged east from Ohio in 2003, it overcame many regional control systems including those of the New York state ISO; but ISO-NE was able to stop the surge short and spare most of New England from its effects.

Even though Maine generates more power than it needs and generally serves as an exporter to the rest of New England, we, too, have had our close calls, largely related to our notorious dependency on natural gas. Gas represents 40% of New England’s total electric capacity, and 49% for Maine alone, compared to 20% in the rest of the nation.

On Saturday, December 1, 2007, an equipment failure in the Sable Island fields disrupted gas supplies to the principal pipeline feeding Maine. Three of Maine’s five gas-fired plants dropped off line, resulting in a loss of 1,370 MW, over half of Maine’s total capacity. ISO-NE responded by importing power from outside New England and calling on a number of factories to shut down, thus saving the rest of us from browning or blacking out. Other close calls occurred during the cold snap of 2004 and following Katrina in 2005.

Maine Utilities Ride to the Rescue

In response to these local reliability issues, and taking advantage of the special benefits of the 2005 Energy Policy Act, Central Maine Power Company in July of 2008 requested Maine’s PUC to approve construction of a new 345 KV transmission line and numerous ancillary upgrades to better serve all of southern Maine from Newington, NH, to Orrington just south of Bangor. This “Maine Power Reliability Project” (MPRP) is projected to cost $1.4 billion. How much it may cost in the end is anybody’s guess.

At the same time, CMP joined with Maine Public Service (MPS) in Aroostook County to seek approval of a 200-mile 345 KV line from Detroit, ME, to Limestone, to provide a direct connection from northern Maine to the rest of New England without having to wheel power through New Brunswick. This “Maine Power Connection Project” (MPC) is estimated to cost $635M. In a separate federal proceeding, CMP has asked FERC to declare that investments in both these projects are entitled under the 2005 Energy Policy Act to a bonus rate of return of 13.14%, about 3% higher than what the Maine PUC would ordinarily allow for utility investments under its jurisdiction. By way of further contrast, a public utility can borrow money in the corporate bond market for only 7%. In the meantime, the utilities are asking ISO-NE to qualify both proposals as “Pool Transmission Facilities” under the tariff rules that ISO administers. If they do qualify, then the cost will be “socialized,” i.e., paid for by ratepayers throughout New England. Because Maine is only 8.4% of the ISO-NE market, over 9/10 of the cost of these projects may be paid for by the other five states. Maine ratepayers are already paying our small share for reliability projects in Connecticut and Massachusetts, and the other states are contributing to Maine’s recently completed 345 KV line from Orrington to New Brunswick.

A Bias Toward Transmission

In any area where there is a shortage of power, the issue can be addressed either by building more generators close to the load, or by building transmission lines to import power from a surplus region, or by doing a bit of both. The challenge, in any case, is to define the “least cost alternative” so that ratepayers get the cheapest form of reliable power. …

Since deregulation, the world of electric power in New England has been divided into two investment camps: the generators who sell power across political lines in open markets; and the transmission and distribution (T&D) utilities whose distribution rates continue to be controlled by state agencies like the Maine PUC and whose transmission rates are controlled by ISO-NE and FERC.

Most experts conclude that the present system, dominated by federal regulators, is heavily biased toward building transmission. As noted above, the Energy Policy Act of 2005 creates powerful rewards for T&D utilities to invest in new transmission corridors and provides a federal preemption where necessary to overcome local barriers.

ISO-NE derives its authority from the T&D utilities through contracts that are approved and regulated by FERC. ISO-NE’s stated mission is to ensure reliability and the adequacy of supply. Cost is a tertiary consideration left largely to the market. Under current ISO-NE policies, most transmission projects will qualify for socialized funding. Therefore, each state has a near-term advantage to approve such lines knowing that the cost will be spread among neighbor states. But if all of the neighbors behave the same way, there is a distinct risk of spending more on transmission than New England requires.

Maine’s Place

The millions of people who live south of Maine from Boston to New York create huge demands for electricity; but because supply is so limited, they have the highest power costs in America.

To the north and east of Maine, by contrast, power is cheaper, a blend of hydro, nuclear, and wind sources from Quebec and New Brunswick. In addition, Maine has its own supply surplus and the potential to generate even more power from wind, bio-mass, and hydro — if only we could move the electrons south to those who need them.

And that’s a problem. Existing power lines running from central Maine to the south can’t carry any greater peak load, either from within Maine or from our Canadian neighbors.

As one economist put it, Maine is sandwiched between 6¢ power to our north and a 10¢ market to our south. That price gap, as well as the reliability issue, is creating pressure to build transmission to move electricity from northern generators to southern customers.

Unfortunately for Maine, our own power costs are linked to the broader New England market. Because generators in Maine have the right by federal law to sell their power anywhere they want, Mainers pay almost as much for electricity as do consumers in Connecticut. Our slight price advantage derives from two factors: (1) A user close to the generator can buy power with less attenuation loss; and (2) at times of peak demand, congestion on the transmission lines limits the amount of power that can be sold out of Maine.

The building of proposed new transmission to New Hampshire will eliminate Maine’s congestion advantage; but CMP argues that this cost increase will be offset by a general reduction in New England power prices made possible by the new line to Aroostook that will bring in less costly power from northern Maine and Canada.

While the transmission project in southern Maine will likely be paid for as a socialized cost by all of New England, other states object to having to contribute to the northern project in the same fashion. To counter this resistance, the two sponsoring utilities, CMP and MPS, have presented a study to show that the anticipated cost ($635M) will be more than offset by a $1B savings for all of New England through reductions in the cost of power over the next ten years. Maine’s share of the projected ten-year savings is $189M. …

Part 2: Capturing the Wind

… Wind power has captured the imagination of many policy-makers, business executives, regulators, environmentalists, and ordinary Maine people eager for clean, renewable, and cheap energy. Will Maine reap benefits from wind power? …

The heads of regulatory agencies in Massachusetts and Connecticut have protested vigorously that their ratepayers should not have to share the cost of a 200-mile high-tension line to connect Aroostook County to the New England grid. In other regions of the country, the costs of transmission lines are divided between region- wide ratepayers and those who receive a more direct economic benefit. The line to Aroostook will benefit primarily a single wind developer, Aroostook Wind Energy (AWE), that plans to build 800 MW of new wind power to sell to southern Maine and the rest of New England. Maine Public Service says it has received connection requests for an additional 450 MW from other sources.

While Aroostook Wind and others are waiting for new transmission to be built to accommodate their projects, other wind developers have gone on ahead, most notably First Wind, whose 42 MW of power on Mars Hill is already being sold locally or wheeled through New Brunswick. First Wind is also constructing 57 MW on Stetson Mountain in Washington County, this one with its own transmission line to the New England grid. Another company, TransCanada, is building 132 MW on Kibby Mountain in Franklin County, and Portland’s Competitive Energy Services is completing a 4.5 MW project in Freedom. Both these companies are paying for their own interconnections.

The Governor’s Task Force on Wind Power Development set a goal of 2,000 MW of installed wind power capacity in Maine by 2015 and 3,000 MW by 2020, but nothing of this magnitude can be achieved without building new transmission lines, regardless of who pays for them.

Obviously, the near-term construction jobs for these projects will benefit Maine’s economy; but once all the transmission has been built and the turbines are up and spinning, the question needs to be posed: What is the net benefit for Maine citizens and ratepayers?

While the power itself is practically free, that benefit belongs primarily to the investors who put up the capital to install the turbines. In the New England power market, all the states have laws that require a premium to be paid for renewable power. Given these opportunities, no wind company will volunteer to give Maine a special rate just for hosting the site.

Because it takes remarkably little effort to maintain a turbine, there are few permanent jobs created by a wind power project. In Mars Hill, 28 turbines are managed and maintained by only five people.

Wind Taxes

Real estate tax benefits are substantial but restricted to the jurisdiction with taxing authority – as they famously were in Wiscasset during the time of Maine Yankee. Every megawatt of wind power capacity costs about $1.5M in new capital investment; but the tax benefits diminish rapidly as the equipment depreciates in value over the 20-year life of each turbine.

If 1,000 megawatts of wind power are built in the Unorganized Territories (UT), it will temporarily increase the assessed value of the entire UT by $1.5B or approximately 50%. The UT already has the lowest tax rates in Maine, and wind power could reduce them by a third more. But the benefit will accrue primarily to those who own land in the UT, the large out-of-state owners like Irving, Wagner, and Plum Creek who already benefit from special “tree growth” tax treatment of their forest lands and who stand to gain substantially from leasing their ridge tops to the wind developers.

If the project falls within a small town, the benefit is extraordinarily narrow. For example, in Highland Plantation, 90% of the town is owned by Bayroot (Wagner) whose tax liabilities are already limited by “tree growth” tax treatment. They presently pay about 1/3 of the town’s taxes, $87,000 per year, for 25 square miles of land that includes five ridge tops suitable for turbines.

If a wind developer invests $100M on Bayroot land, Highland’s total valuation will rise from $7.5M to $107.5M in one year. The mill rate will drop to 1/14 of its present level for the benefit of one major landowner and 58 local residents. The developer will pay only 2 mills in taxes for the privilege of generating power for the Connecticut market. Property taxes paid elsewhere by Maine homeowners and small businesses average 17 mills.

TIFs

All three of the large-scale wind projects that have so far been approved have received benefits under Maine’s Tax Increment Finance Law (TIF). In Mars Hill, these benefits were granted by the town. Stetson and Kibby are both in the UT where county commissioners control the decisions.

Under a TIF, the developer and the taxing jurisdiction may shelter some or all of the new assessed value to avoid the town’s loss of school funding and municipal revenue sharing and to avoid having to pay an increase in county taxes. The developer still pays a tax on the sheltered value but the tax is often partly refunded as a “credit enhancement” to help pay for the project. The remainder may be kept by the town for the restricted purpose of economic development.

In the Unorganized Territories, the amount reserved must be spent on economic development within unorganized portions of the affected county, but these are areas where LURC zoning forbids nearly all forms of development.

For the Stetson Mountain project, Washington County Commissioners gave back to the developer 60% of all real estate taxes for the first 20 years (estimated at $5.6M). The remaining 40% ($3.75M) will be retained for such projects as a revolving loan fund and development planning for the Washington County UT.

The Kibby Mountain project in Franklin County is over twice as large as Stetson. The commissioners agreed to return to the developer about 40% of the taxes for 20 years, which is tantamount to an $8.8M subsidy to the New England power market. Amounts retained by the county ($4M over 20 years) will be spent on scenic by-way improvements, a revolving loan fund, and tourism marketing.

Advocates for both of these TIFs in the Unorganized Territories were clearly straining to find ways to spend the money. When owners of the next ridge top apply for a TIF within either county, the commissioners may be hard pressed to do anything but give the money back to the developer, a result that will primarily benefit either the company’s owners or southern New England rate payers at Maine’s expense.

Sovereignty and Destiny

While wind power in Maine creates economic and environmental benefits for New England — and for Maine as part of that region, it is difficult to define a substantial long-term benefit that will accrue specifically to Maine people. Our power bills will not be noticeably cheaper; real estate taxes from these projects will not be broadly beneficial; and the number of new jobs will be small.

Some have suggested that CMP and Bangor Hydro should be ordered to withdraw from ISO-NE when contracts come up for renewal in 2010, in hopes that we might reestablish more complete control of our T&D companies and the supply of power to Maine customers. Under a directive from the Legislature, this very issue is being litigated before the PUC with a decision due by January of 2009.

Even if Maine’s utilities withdraw from ISO-NE or form an alternative alliance with New Brunswick, generators in Maine would still have the right to sell their power in inter-state commerce over Maine transmission lines at a non-discriminatory rate. Maine would still have to contract with the New England power market to guarantee reliability, as required by good management and by federal law. And Maine would lose the opportunity to socialize the cost of new transmission facilities. Those costs would have to be borne either by generators or by Maine ratepayers without financial participation from other states.

On the other hand, many argue that Maine should get out of ISO-NE while the getting is good. The Energy Policy Act of 2005 is irrationally biased in favor of high-cost transmission, and the policies of ISO-NE have amplified those irrationalities to the point where costs may soon run amuck.

In addition, in its role as manager of the energy supply, ISO-NE recently imposed a substantial rate increase that will be used to encourage the building of new generators primarily in southern New England. Many feel that Maine’s allocated share of that cost is too large.

Scale of the Issue

Maine consumers presently pay about 15¢ for each kilowatthour (10¢ for energy, 5¢ for T&D). Thus it costs only 15¢ to iron a few shirts, to watch television for an evening or to leave a couple of lights on all night.

But every year Maine’s homes and businesses burn through more than 12 billion of these little units at an aggregate cost of nearly two billion dollars.

The burden to our economy is the same as imposing a 4% sales tax on the entire domestic product of our state — except that few of the proceeds are spent here. The money is used to buy natural gas, oil, or nuclear power from people who may not be our friends, or it pays dividends to Spanish shareholders who are buying CMP.

… Because wind is intermittent and often blows at times of low electricity demand, it can only be exploited as part of a larger and more balanced market than what Maine alone can supply. Nevertheless, it will be a shame to allow the entire benefit to flow beyond our border — which is exactly where it is headed without the intelligent assertion of Maine’s sovereignty. …

Choices, Maine Center for Economic Policy, Vol. IX, Nos. 8 & 9, October 17 & 20, 2008Download “Megawatts from mountain tops: What’s in it for Maine?”

Wind turbines are large vibrating cylindrical towers, strongly coupled to the ground with massive concrete foundation, through which vibration are transmitted to the surrounding and with rotating turbine blades generating low-frequency acoustic signals which may couple acoustically into the ground. This may occur in several ways:

1. As a cantilever carrying the nacelle/blade mass, with frequencies typically less than 1Hz, depending on height of tower.
2. As a torsional oscillator at low frequencies.
3. As a complex distributed system at higher frequencies

Additionally, the blade-tower interaction is a source of pulses at a low repetition rate, which contain components in the infrasound region. The local and surrounding geology, especially layering, may play an important part in determining vibration transmission. Energy may propagate via complex paths including directly through the ground or principally through the air and then coupling locally into the ground …

Applied and Environmental Geophysics Research Group, Earth Sciences and Geography, School of Physical and Geographical Sciences, Keele University

18 July 2005

Download “Microseismic and Infrasound Monitoring of Low Frequency Noise and Vibrations from Windfarms: Recommendations on the Siting of Windfarms in the Vicinity of Eskdalemuir, Scotland”

January 16, 2001

EXECUTIVE SUMMARY

This report, which was prepared at the request of Rep. Henry A. Waxman, examines the White House energy plan prepared by the White House energy task force under the direction of Vice President Cheney and compares the policies in the White House energy plan to those advocated by Enron. The analysis in the report is based on testimony of Enron officials before Congress, other public statements by Enron officials, Enron lobbying materials distributed to Congress, lobbying disclosure reports filed by Enron lobbyists, and news accounts of Enron positions.

The White House energy task force was formed on January 29, 2001, under the name the White House National Energy Policy Development Group (NEPD Group). The President released the White House energy plan that the task force developed on May 17, 2001. According to the Office of the Vice President, the task force met six times with Enron executives. The first meeting took place on February 22, 2001, about three weeks after the formation of the task force. On April 17, 2001, the Vice President met personally with Enron CEO Kenneth Lay to discuss the energy policy. The last meeting between task force officials and Enron executives apparently took place on October 10, 2001, less than one week before Enron announced the $1.2 billion reduction in shareholder value that precipitated Enron’s collapse.

The analysis in this report reveals that numerous policies in the White House energy plan are virtually identical to the positions Enron advocated. In total, there are at least 17 policies in the White House energy plan that were advocated by Enron or that benefitted Enron financially. These policies fall into four general categories: (1) policies that promote the deregulation of the electricity market; (2) policies that promote energy derivatives and commodities markets; (3) policies that expand natural gas and oil production; and (4) other policies that benefitted Enron.

In the area of electricity deregulation, the White House energy plan supports an expansive form of the controversial policy of “open access,” which guarantees energy traders like Enron access to the transmission lines of electric utilities. In 1999, Enron told members of Congress that this policy was Enron’s “single most important initiative.” The White House plan also supports the repeal of the Public Utility Holding Company Act (PUHCA), an action that would have enabled Enron to increase its ownership of electric utility companies. In February 2000, Enron lobbied Congress for “a provision granting FERC-certified transmission projects the power of eminent domain” so that power lines could be constructed more expeditiously. The White House energy plan endorses this policy, even though it conflicts with traditional state authority over transmission siting decisions. In addition, the plan includes several other deregulation initiatives supported by Enron, including one provision that would help energy traders like Enron gain new rights of access to the power lines maintained by the Bonneville Power Administration. …

Even in areas where Enron did not get every policy it advocated, the White House energy plan is helpful to the company. In the area of global warming, for example, the plan does not support the mandatory controls on carbon dioxide emissions sought by Enron. But the plan does direct federal agencies to identify “market mechanisms” to address global warming, which would help develop the type of market in carbon credits sought by Enron.

The policies in the White House energy plan did not benefit Enron exclusively. And some of the policies may have independent merit. Nevertheless, it is unlikely that any other corporation in America stood to gain as much from the White House energy plan as Enron.

II. RECOMMENDATIONS RELATING TO ENERGY DERIVATIVES AND COMMODITIES MARKETS

B. Emissions Credits

Enron Position. Enron has promoted commodities trading markets in a wide number of areas, from weather derivatives to forest products and from electricity to metals. In particular, Enron has lobbied extensively for government policies that would support new or expanded markets in areas such as carbon and air emissions credits, which are bought and sold by Enron Global Markets. For example, Enron supported development of an international market in carbon dioxide emissions under a climate change agreement.

White House Energy Plan. The White House energy plan recommended policies that would expand and develop several new markets for emissions credits. The White House energy plan does not endorse the Kyoto Protocol on climate change or mandatory controls on carbon dioxide, but it does recommend use of market mechanisms to address climate change. The plan states:

The NEPD Group recommends that the President direct federal agencies … to identify environmentally and cost-effective ways to use market mechanisms and incentives … and cooperate with allies, including through international processes, to develop technologies, market-based incentives, and other innovative approaches to address the issue of global climate change.”

As part of a proposal supporting legislation to reduce emissions from electric power generators, the energy plan recommended establishing “mandatory reduction targets for emissions of three main pollutants: sulfur dioxide, nitrogen oxides, and mercury,” and measures to “[p]rovide market-based incentives, such as emissions trading credits to help achieve the required reductions.”

The recommendation for emission trading credits is one of only three recommendations in the White House energy plan chapter on the environment, and it is the only one of the three that pertains to pollution from energy production.

IV. OTHER RECOMMENDATIONS THAT BENEFITTED ENRON

C. Promotion of Wind Power

Enron Position. Enron Wind designs and manufactures wind turbines, and Enron owns six wind power generation plants. Enron has lobbied aggressively for extension of the wind and biomass tax credit. For example, in the first six months of 2001, Enron paid outside lobbyists over $200,000 for work on wind power issues, in addition to conducting its own lobbying on these issues.

White House Energy Plan. Consistent with Enron’s position, the White House energy plan recommended extending the wind and biomass tax credit and taking other actions that would promote the wind turbine business. The plan states:

• The NEPD Group recommends that the President direct the Secretary of the Treasury to work with Congress on legislation to extend and expand tax credits for electricity produced using renewable technology, such as wind and biomass. The President’s budget request extends the present 1.7 cents per kilowatt hour tax credit for electricity produced from wind and biomass.
• The NEPD Group recommends that the President direct the Secretaries of the Interior and Energy to work with Congress on legislation to use an estimated $1.2 billion of bid bonuses from the environmentally responsible leasing of ANWR for funding research into alternative and renewable energy resources, including wind, solar, geothermal, and biomass.

Download “How the White House Energy Plan Benefitted Enron”

Also see:  “Enron’s Ken Lay asks for Texas Gov. Bush’s help in securing tax credits for wind”

Wind turbines “can have negative impacts on bat populations as well as on their prey and habitats, such as:
• Damage, disturbance or destruction of foraging habitats and commuting corridors;
• Damage, disturbance or destruction of roosts;
• Increased collision risk for bats in flight;
• Disorientation of bats in flight through emission of ultrasound noise.”

Download “Guidelines for consideration of bats in wind farm projects”

WHEREAS, wind turbines were once assumed to have no adverse environmental impacts, however, onshore wind-energy facilities have killed thousands of bats and birds (Government Accountability Office 2003; Kunz et al. 2007b; National Research Council 2007); and,

WHEREAS, onshore wind-turbine construction and associated infrastructure have pronounced effects on wildlife habitat (Government Accountability Office 2005; Arnett et al. 2007), including increased habitat loss and fragmentation and subsequent loss of species from areas around developments, and alteration of dispersal or migration corridors; and,

WHEREAS, many onshore and offshore wind-energy facilities are being planned and constructed without adequately considering the potential or actual effects on wildlife (Barclay et al. 2007; Cryan and Brown 2007; Kunz et al. 2007b; National Research Council 2007); and

WHEREAS, fatalities of bats and other wildlife at existing onshore wind-energy facilities have raised concern that wind turbines may have population-level impacts on these species (Kunz et al. 2007b; Arnett et al. 2008); and,

WHEREAS, researchers independent of the wind industry have been unable to adequately evaluate the magnitude of impacts because of limited access to wind-energy facilities, but preliminary results indicate that species such as migratory tree bats already may be experiencing fatality rates that will lead to population declines (Kunz et al. 2007; Arnett et al. 2008); and,

WHEREAS, the cumulative impacts of wind-energy development on wildlife likely will increase as new facilities are constructed (Kunz et al. 2007b; National Research Council 2007); and,

WHEREAS, proposed and existing wind-energy projects have the potential to severely impact species that cross state and national borders, particularly continental migrants, such that no single state or regional agency can adequately analyze or assess the cumulative impacts of these projects on wildlife (National Research Council 2007; Arnett et al. 2008); and,

WHEREAS, scientific guidance and leadership are required before negative effects on wildlife become severe and irreversible (Kunz et al. 2007; Arnett et al. 2008);

THEREFORE BE IT RESOLVED that the American Society of Mammalogists, meeting at their 88th Annual Meeting, South Dakota State University, Brookings, South Dakota, 21-25 June 2008, recommends the following steps be implemented to provide appropriate protection for our valuable wildlife resources:

(a) Commitments to comprehensive environmental assessments that include multi-year pre- and multi-year post-construction studies be made prior to selection and construction of sites for wind energy facilities (U.S. Fish and Wildlife Service, 2003; Government Accountability Office 2005; National Research Council 2007).

(b) Environmental assessments by professional biologists or organizations with no conflict of interest in any aspect of financing construction or operation of wind energy facilities (Kunz et al. 2007a; National Research Council 2007).

(c) Independent external review of evaluations and reports before siting of wind energy facilities to insure the techniques and interpretation of results are appropriate, adequate, scientifically rigorous, and in the public domain Kunz et al. 2007a; Arnett et al 2008).

(d) Siting and placement of turbines and their associated infrastructure to avoid fragmenting large contiguous tracts of wildlife habitat (Arnett et al. 2007; National Research Council 2007).

(e) Siting and placement that avoids bat hibernation, breeding, and maternity colonies, or flight paths between colonies and feeding areas (Arnett et al. 2007; Cryan and Brown, 2007; National Research Council 2007).

(f) Siting and placement to avoid local pathways of bat or bird migration or areas where these species are highly concentrated (Arnett et al 2007; National Research Council 2007).

(g) Siting and placement that avoids documented locations of any species of wildlife protected under State or Federal authority, that could be affected adversely (U.S. Fish and Wildlife Service 2003; Arnett et al. 2007).

(h) Increased research on effects of onshore and offshore wind-energy facilities to assess the nature and extent of risks to wildlife (Arnett et al. 2007, 2008; Kunz et al. 2007a, 2007b). (i) Systematic investigation of effectiveness of operational procedures, such as feathering of blades or voluntary temporary shutdowns that might reduce impacts of wind turbines on wildlife (Barclay et al. 2007; Cryan and Brown 2007; Horn et al. 2008; Kunz et al 2007a; National Research Council 2007.

(j) Implementation of scientific peer-review of all aspects of wind-energy development (U.S. Fish and Wildlife Service, 2003; Government Accountability Office 2005; Kunz et al. 2007b; National Research Council 2007).

References

Arnett, E. B., D. B. Inkley, D. H. Johnson, R. P. Larkin, S. Manes, A. M. Manville, J. R. Mason, M. L. Morrison, M. D. Strickland, and R. Thresher. 2007. Impacts of wind energy facilities on wildlife and wildlife habitat. Wildlife Society Technical Review 07-2. The Wildlife Society, Bethesda, Maryland, USA.

Arnett, E.B., K. Brown, W.P. Erickson, J. Fielder, T.H. Henry, G.D. Johnson, J. Kerns,

R.R. Kolford, T. Nicholson, T. O’Connell, M. Piorkowski, and R. Tankersly. 2008. Patterns of fatality of bats at wind energy facilities in North America. Journal of Wildlife Management 72: 61-78. Barclay, R.M.R., E.F. Bearwald, and J.C. Gruver. 2007. Variation in bat and bird fatalities at wind energy facilities: assessing the effects of rotor size and tower height. Canadian Journal of Zoology 85: 381-387.

Cryan, P.M., and A.C. Brown. 2007. Migration of bats past remote island offers clues to the problem of bat fatalities at wind turbines. Biological Conservation, 139: 1-11.

Government Accountability Office Report to Congressional Requesters. 2005. Wind Power, Impacts on Wildlife and Government Responsibilities for Regulating Development and Protecting Wildlife. GAO-05-906. Washington D. C., 64 pp. http://www.gao.gov/cgi-bin/getrpt?GAO-05-906

Horn, J. W. E. B. Arnett and T. H. Kunz. 2008. Behavioral responses of bats to operating wind turbines. Journal of Wildlife Management 72: 123-132. http://www.wind-watch.org/documents/wpcontent/uploads/horn_et_al_2008.pdf

Kunz, T. H., E. B. Arnett, B. M. Cooper, W. P. Erickson, R. P Larkin, T. Mabee, M. L. Morrison, M. D. Strickland, and J. M. Szewczak. 2007a. Assessing impacts of wind-energy development on nocturnally active birds and bats: a guidance document. Journal of Wildlife Management 71: 2449-4486. http://www.wind-watch.org/documents/wp-content/uploads/wild-71-0845.pdf

Kunz, T. H., E. B. Arnett, W. P. Erickson, A. R. Hoar, G. D. Johnson, R. P. Larkin, M. D. Strickland, R. W. Thresher, and M. D. Tuttle. 2007b. Ecological impacts of wind energy development on bats: questions, research needs, and hypotheses. Frontiers of Ecology and Environment, 5: 315-324. http://www.wind-watch.org/documents/wp-content/uploads/kunzbatswind.pdf

National Research Council. 2007. Environmental Impacts of Wind-Energy Projects. National Academies Press, Washington, D.C. http://www.eswr.com/latest/307/nrcwind.htm

U.S. Fish and Wildlife Service. 2003. Memorandum to Regional Directors, Regions 1-7 on Service Interim Guidance on Avoiding and Minimizing Wildlife Impacts from Wind Turbines, 13 May 2003, 57 pp. http://www.fws.gov/habitatconservation/wind.pdf

Download “ASM Resolution: Effects of Wind-Energy Facilities on Bats and Other Wildlife”

Download ‘The “how to” guide to criteria for siting wind turbines to prevent health risks from sound’

Prepared for the California Wind Energy Collaborative
By Scott Larwood, University of California, Davis

June 16, 2005

Download the paper.
Download the presentation.

• George W. Kamperman, INCE Bd. Cert. Emeritus, INCE Kamperman Associates, Inc., george@kamperman.com
• Richard R. James, E-Coustic Solutions, rickjames@e-coustic.com

Rev. 1.0, July 27, 2008

Industrial scale wind turbines are a familiar part of the landscape in Europe, U.K., and other parts of the world. In the U.S., however, similar industrial-scale wind energy developments are just beginning operation. The presence of industrial wind projects will increase dramatically over the next few years given the push by the Federal and state governments to promote renewable energy sources through tax incentives and other forms of economic and political support. States and local governments in the U.S. are promoting what appear to be lenient rules for how industrial wind farms can be located in communities, which are predominantly rural and often very quiet. Studies already completed and currently in progress describe significant health effects associated with living in the vicinity of industrial grade wind turbines. This paper reviews sound studies conducted by consultants for governments, the wind turbine owner, or the local residents for a number of sites with known health or annoyance problems. The purpose is to determine if a set of simple guidelines using dBA and dBC sound levels can serve as the “safe” siting guidelines. Findings of the review and recommendations for sound limits will be presented. A discussion of how the proposed limits would have affected the existing sites where people have demonstrated pathologies apparently related to wind turbine sound will also be presented.

… Our review covered the community noise studies performed in response to complaints, research on health issues related to wind turbine noise, critiques of noise studies performed by consultants working for the wind developer, and research/technical papers on wind turbine sound immissions and related topics. The papers are listed in Tables 1-4.

Table 1 — List of Studies Related to Complaints

• Resource Systems Engineering, Sound Level Study — Ambient & Operations Sound Level Monitoring, Maine Department of Environmental Protection Order No. L-21635-26-A-N, June 2007
• ESS Group, Inc., Draft Environmental Impact Statement For The Dutch Hill Wind Power Project — Town of Cohocton, NY, November 2006
• David M. Hessler, Environmental Sound Survey and Noise Impact Assessment — Noble Wethersfield Wind Park — Towns of Wethersfield and Eagle NY, For: Noble Environmental Power, LLC, January 2007
• George Hessler, “Report Number 101006-1, Noise Assessment Jordanville Wind Power Project,” October 2006
• HGC Engineering, “Environmental Noise Assessment Pubnico Point Wind Farm, Nova Scotia, Natural Resources Canada Contract NRCAN-06-0046,” August 23, 2006
• John I. Walker, “Sound Quality Monitoring, East Point, Prince Edward Island” by Jacques Whitford, Consultants for Prince Edward Island Energy Corporation, May 28, 2007

Table 2 — List of Studies Related to Health

• Nina Pierpont, “Wind Turbine Syndrome — Abstract” from draft article and personal conversations. www.ninapierpont.com
• Nina Pierpont, “Letter from Dr. Pierpont to a resident of Ontario, Canada, re: Wind Turbine Syndrome,” Autumn 2007
• Amanda Harry, “Wind Turbine Noise and Health” (2007)
• Barbara J. Frey and Peter J. Hadden, “Noise Radiation from Wind Turbines Installed Near Homes, Effects on Health” (2007)
• Eja Pedersen, “Human response to wind turbine noise — Perception, annoyance and moderating factors, Occupational and Environmental Medicine,” The Sahlgrenska Academy, Gotenborg 2007
• Robin Phipps, “In the Matter of Moturimu Wind Farm Application, Palmerston North, Australia,” March 2007
• WHO European Centre for Environment and Health, Bonn Office, “Report on the third meeting on night noise guidelines,” April 2005

Table 3 — List of Studies That Review Siting Impact Statements

• Richard H. Bolton, “Evaluation of Environmental Noise Analysis for ‘Jordanville Wind Power Project’,” December 14, 2006 Rev 3
• Clifford P. Schneider, “Accuracy of Model Predictions and the Effects of Atmospheric Stability on Wind Turbine Noise at the Maple Ridge Wind Power Facility,” Lowville, NY — 2007

Table 4 — List of Research and Technical papers Included in Review Process

• Anthony L. Rogers, James F. Manwell, Sally Wright, “Wind Turbine Acoustic Noise,” Renewable Energy Research Laboratory, Dept. of ME and IE, U of Mass, Amherst, amended June 2006
• ISO. 1996. Acoustics — Attenuation of sound during propagation outdoors — Part 2: General method of calculation. International Organization of Standardization. ISO 9613-2. p. 18
• G.P. van den Berg, “The Sounds of High Winds — the effect of atmospheric stability on wind turbine sound and microphone noise,” Ph.D. thesis, 2006
• Fritz van den Berg, “Wind Profiles over Complex Terrain,” Proceedings of Second International Meeting on Wind Turbine Noise, Lyons, France, Sept. 2007
• William K. G. Palmer, “Uncloaking the Nature of Wind Turbines — Using the Science of Meteorology,” Proceedings of Second International Meeting on Wind Turbine Noise, Lyons, France, Sept. 2007
• Soren Vase Legarth, “Auralization and Assessment of Annoyance from Wind Turbines,” Proceedings of Second International Meeting on Wind Turbine Noise, Lyons, France, Sept. 2007
• Julian T. and Jane Davis, “Living with aerodynamic modulation, low frequency vibration and sleep deprivation — how wind turbines inappropriately placed can act collectively and destroy rural quietitude,” Proceedings of Second International Meeting on Wind Turbine Noise, Lyons, France, Sept. 2007
• James D. Barnes, “A Variety of Wind Turbine Noise Regulations in the United States — 2007,” Proceedings of Second International Meeting on Wind Turbine Noise, Lyons, France, Sept. 2007
• M. Schwartz and D. Elliott, “Wind Shear Characteristics at Central Plains Tall Towers,” NREL 2006
• IEC 61400 “Wind turbine generator systems, Part 11: Acoustic noise measurement techniques,”.rev:2002

After reviewing the materials in the tables; we have arrived at our current understanding of wind turbine noise and its impact on the host community and its residents. The review showed that some residents living as far as 3 km (two (2) miles) from a wind farm complain of sleep disturbance from the noise. Many residents living one-tenth this distance (300 m. or 1000 feet) from a wind farm are experiencing major sleep disruption and other serious medical problems from nighttime wind turbine noise. The peculiar acoustic characteristics of wind turbine noise immissions cause the sounds heard at the receiving properties to be more annoying and troublesome than the more familiar noise from traffic and industrial factories. Limits used for these other community noise sources do not appear to be appropriate for siting industrial wind turbines. The residents who are annoyed by wind turbine noise complain of the approximately one (1) second repetitive swoosh-boom-swoosh-boom sound of the turbine blades and “low frequency” noise. It is not apparent to these authors whether the complaints that refer to “low frequency” noise are about the audible low frequency part of the swoosh-boom sound, the one-hertz amplitude modulation of the swoosh-boom sound, or some combination of both acoustic phenomena.

To assist in understanding the issues at hand, the authors developed the “conceptual” graph for industrial wind turbine sound (Figure 1). This graph shows the data from one of the complaint sites plotted against the sound immission spectra for a modern 2.5 MWatt wind turbine; Young’s threshold of perception for the 10% most sensitive population (ISO 0266); and a spectrum obtained for a rural community during a three hour, 20 minute test from 11:45 pm until 3:05 am on a windless June evening in near Ubly, Michigan a quiet rural community located in central Huron County. (Also called: Michigan’s Thumb.) It is worth noting that this rural community demonstrates how quiet a rural community can be when located at a distance from industry, highways, and airport related noise emitters.

During our review we posed a number of questions to ourselves related to what we were learning. The questions (italics) and our answers are:

Do National or International or local community Noise Standards for siting wind turbines near dwellings address the low frequency portion of the wind turbine’s sound immissions? No! State and Local governments are in the process of establishing wind farm noise limits and/or wind turbine setbacks from nearby residents, but the standards incorrectly presume that limits based on dBA levels are sufficient to protect the residents.

Do wind farm developers have noise limit criteria and/or wind turbine setback criteria that apply to nearby residents? Yes! But the Wind Industry recommended residential wind turbine noise levels (typically 50-55 dBA) are too high for the quiet nature of the rural communities and may be unsafe for the nearest residents. An additional concern is that some of the methods for implementing pre-construction computer models may predict sound levels that are too low. These two factors combined can lead to post-construction complaints and health risks.

Are all residents living near wind farms equally affected by wind turbine noise? No, children, people with pre-existing medical conditions, especially sleep disorders, and the elderly are generally the most susceptible. Some people are unaffected while some nearby neighbors develop serious health effects caused by exposure to the same wind turbine noise.

How does wind turbine noise impact nearby residents? Initially, the most common problem is chronic sleep deprivation during nighttime. According to the medical research documents, this may develop into far more serious physical and psychological problems

What are the technical options for reducing wind turbine noise immission at residences? There are only two options: 1) increase the distance between source and receiver; and/or 2) reduce the source sound power immission. Either solution is incompatible with the objective of the wind farm developer to maximize the wind power electrical generation within the land available.

Is wind turbine noise at a residence much more annoying than traffic noise? Yes, researchers have found that “Wind turbine noise was perceived by about 85% of the respondents even when the calculated A-weighted SPL were as low as 35.0-37.5 dB. This could be due to the presence of amplitude modulation in the noise, making it easy to detect and difficult to mask by ambient noise.” [JASA 116(6), December 2004, pgs 3460-3470, "Perception and annoyance due to wind turbine noise-a dose-relationship" Eja Pedersen and Kerstin Persson Waye, Dept of Environmental Medicine, Goteborg University, Sweden]

Why do wind turbine noise immissions of only 35 dBA disturb sleep at night? This issue is now being studied by the medical profession. The affected residents complain of the middle to high frequency swooshing sounds of the rotating turbine blades at a constant repetitive rate of about 1 hertz plus low frequency noise. The amplitude modulation of the swooshing sound changes continuously. The short time interval between the blade’s swooshing sounds described by residents as sometimes having a thump or low frequency banging sound that varies in amplitude up to 10 dBA. This may be a result of phase changes between turbine emissions, turbulence, or an operational mode.. The assumptions about wall and window attenuation being 15 dBA or more may not be sufficiently protective considering the relatively high amplitude of the wind turbine’s low frequency immission spectra.

What are the typical wind farm noise immission criteria or standards? Limits are not consistent and may vary even within a particular country. Example criteria include:

• Australia: the lower of 35 dBA or L₉₀ + 5 dBA
• Denmark: 40 dBA
• France: L₉₀ + 3 (night) and L₉₀ + 5 (day)
• Germany: 40 dBA
• Holland: 40 dBA
• United Kingdom: 40 dBA (day) and 43 dBA (night) or L₉₀ + 5 dBA
• Illinois: 55 dBA (day) and 51 dBA (night)
• Wisconsin: 50 dBA
• Michigan: 55 dBA

Note: Illinois statewide limits are expressed only in nine contiguous octave frequency bands with no mention of A-weighting for the hourly leq limits. Typically, wind turbine noise just meeting the octave band limits would read 5 dB below the energy sum of the nine octave bands after applying A-weighting. So the Illinois limits are approximately 50 dBA (daytime 7 AM to 10 PM) and 46 dBA at night, assuming a wind farm is a Class C Property Line Noise Source.

What is a reasonable wind farm sound immission limit to protect the health of residences? We are proposing an immission limit of 35 dBA or L_90A + 5 dBA, whichever is lower, and a C-weighted criteria to address the affected resident’s complaints of wind turbine low frequency noise: For the proposed criteria the dBC sound level at a receiving property shall not exceed L_90A + 20 dB. In other words, the dBC operating immission limit shall not be more than 20 dB above the measured dBA (L_90A) pre-construction nighttime background sound level. A maximum not-to-exceed limit of 50 dBC is also proposed. … The World Health Organization and others have determined a sound emitter’s noise that results in a difference between the dBC and dBA value greater than 20 dB will be an annoying low frequency issue.

Is not L_90A the minimum dBA background noise level? This is correct, but it is very important to establish the statistical average background noise environment outside a potentially affected residence during the quietest (10 pm to 4 am) sleeping hours of the night. This nighttime sleep disturbance has generated the majority of the wind farm noise complaints throughout the world. The basis for a community’s wind turbine sound immission limits would be the minimum 10 minute nighttime L_90A plus 5 dB for the time period of 10 pm to 7 am. This would become the Nighttime Immission Limits for the proposed wind farm. This can be accomplished with one or several 10 minute measurements during any night when the atmosphere is classified stable with a light wind from the area of the proposed wind farm. The Daytime Limits (7 am to 7 pm) could be set 10 dB above the minimum nighttime L_90A measured noise, but the nighttime criteria will always be the limiting sound levels.

A nearby wind farm meeting these noise immission criteria will be clearly audible to the residents occasionally during nighttime and daytime. Compliance with this noise standard would be determined by repeating the initial nighttime minimum nighttime L_90A tests and adding the dBC (L_eqC) noise measurement with the turbines on and off. If the nighttime background noise level (turbines off) was found to be slightly higher than the measured background prior to the wind farm installation, then the results with the turbines on must be corrected to determine compliance with the pre-turbine established sound limits. …

Including wind as a masking source in the criteria is one method for elevating the permissible limits. Indeed the background noise level does increase with surface wind speed. When it does occur, it can be argued that the increased wind noise provides some masking of the wind farm turbine noise emission. However, in the middle of the night when the atmosphere is defined as stable (no vertical flow from surface heat radiation) the layers of the lower atmosphere can separate and permit wind velocities at the turbine hubs to be 2 to 2.5 times the wind velocity at the 10m high wind monitor but remain near calm at ground level. The result is the wind turbines can be operating at or close to full capacity while it is very quiet outside the nearby dwellings.

This is the heart of the wind turbine noise problem for residents within 3 km (approx. two miles) of a wind farm. When the turbines are producing the sound from operation it is quietest outside the surrounding homes. The PhD thesis of P.G. van den Berg “The Sounds of High Winds” is very enlightening on this issue. See also the letter by John Harrison in Ontario “On Wind Turbine Guidelines.” …

The simple fact that so many residents complain of low frequency noise from wind turbines is clear evidence that the single A-weighted (dBA) noise descriptor used in most jurisdictions for siting turbines is not adequate. The only other simple audio frequency weighting that is standardized and available on all sound level meters is the C-weighting or dBC. A standard sound level meter set to measure dBA is increasingly less sensitive to low frequency below 500 Hz (one octave above middle-C). The same sound level meter set to measure dBC is equally sensitive to all frequencies above 32 Hz (lowest note on grand piano). It is well known that dBC readings are more predictive of perceptual loudness than dBA readings if low frequency sounds are significant.

We are proposing to use the commonly accepted dBA criteria that is based on the preexisting background sound levels plus a 5 dB allowance for the wind turbine’s immissions (e.g. L_90A +5) for the audible sounds from wind turbines. But, to address the lower frequencies that are not considered in A-weighted measurements, we are proposing to add limits based on dBC. The Proposed Sound Limits are presented in the text box at the end of this paper. For the current industrial grade wind turbines in the 1.5 to 3 MWatt range, the addition of the dBC requirement will result in an increased distance between wind turbines and the nearby residents. For the generalized graphs shown in Figure 1, the distances would need to be approximately double the current distance. This will result in setbacks in the range of 1 km or greater for the current generation of wind turbines if they are to be located in rural areas where the L_90A background sound levels are 30 dBA or lower. In areas with higher background sound levels, turbines could be located somewhat closer, but still at a distance greater than the 305 m (1000 ft.) or less setbacks commonly seen in U.S. based wind turbine standards set by many states and used for wind turbine developments.

Proposed Wind Turbine Siting Sound Limits

1. Audible Sound Limit
1. No Wind Turbine or group of turbines shall be located so as to cause an exceedance of the pre-construction/operation background sound levels by more than 5 dBA. The background sound levels shall be the L_90A sound descriptor measured during a pre-construction noise study during the quietest time of evening or night. All data recording shall be a series of contiguous ten (10) minute measurements. L_90A results are valid when L_10A results are no more than 15 dBA above L_90A for the same time period. Noise sensitive sites are to be selected based on wind development’s predicted worst-case sound emissions (in L_eqA and L_eqC) which are to be provided by the developer.
2. Test sites are to be located along the property line(s) of the receiving nonparticipating property(s).
3. A 5 dB penalty is applied for tones as defined in IEC 61400-11.
2. Low Frequency Sound Limit
   The L_eqC and L_90C sound levels from the wind turbine at the receiving property shall not exceed the lower of either:
1. L_eqC − L_90A greater than 20 dB outside any occupied structure, or
2. A maximum not-to-exceed sound level of 50 dBC (L_90C) from the wind turbines without other ambient sounds for properties located at one mile or more from State Highways or other major roads or 55 dBC (L_90C) for properties closer than one mile. These limits shall be assessed using the same nighttime and wind/weather conditions required in 1.a. Turbine operating sound immissions (L_eqA and L_eqC) shall represent worst case sound immissions for stable nighttime conditions with low winds at ground level and winds sufficient for full operating capacity at the hub.
3. General Clause
   Not to exceed 35 dBA within 30 m. (approx. 100 feet) of any occupied structure.
4. Requirements
1. All instruments must meet ANSI or IEC Precision integrating sound level meter performance specifications.
2. Procedures must meet ANSI S12.9 and other applicable ANSI standards.
3. Measurements must be made when ground level winds are 2m/s (4.5 mph) or less. Wind shear in the evening and night often results in low ground level wind speed and nominal operating wind speeds at wind turbine hub heights.
4. IEC 61400-11 procedures are not suitable for enforcement of these requirements except for the presence of tones.

Download “Simple guidelines for siting wind turbines to prevent health risks”

2 NOISE CRITERIA

The general approach in setting noise criteria for new developments is to require compliance with a base noise level.

This base noise level is typically 5 dB(A) lower than the level considered to reflect the amenity of the receiving environment. Designing new developments at a lower level accounts for the cumulative effect of noise from other similar development and for the increased sensitivity of receivers to a new noise source.

The impact of a given noise is also closely linked to the amount it exceeds the background noise. For example, the same noise in a quiet rural area will generally have a greater adverse impact than in a busy urban area because of the masking effect of high ambient noise environments.

If the noise generated does not exceed the background noise by more than 5 dB(A) the impact will be marginal and acceptable.

A unique characteristic of wind farms is that the noise level from each wind turbine generator (WTG) increases as the wind speed at the site increases. As an offset, the background noise also generally increases under these conditions and can mask the WTG noise.

Comparison with a base noise level alone will therefore not be sufficient to indicate the potential impact of a wind farm: a farm could comply with this base level at lower wind speeds but exceed it when the wind speed rises.

Most international and interstate jurisdictions … set a base noise level for low wind speeds and also ensure that the wind farm noise does not exceed the background noise by more than 5 dB(A) as the wind speed increases.

This general approach recognises the unique noise generating characteristics of wind turbines and the particular ambient noise environments of most sites and is the one used by these guidelines.

Most wind farm sites are within or next to areas where low ambient noise levels are a significant component of that area’s amenity. These might include rural living zones or zones that are not intended to be subject to any other significant ambient noise sources from adjacent premises. …

— – — –
The New Zealand Standard NZS 6808 sets the predicted base level (LAeq) at 40 dB(A). This is higher than the approach of these guidelines, but the specified propagation model to be used in accordance with that standard does not account for factors such as ground absorption and topography effects that can substantially reduce the noise level in practice. In addition, the New Zealand Standard requires the criteria to be met at all receivers, regardless of their relative amenity or relationship with the wind farm development.

A comprehensive publication developed by the wind farm industry for the UK Department of Trade and Industry (1996) sets the base level (LA90) at 35 — 40 dB(A). The actual value chosen within this range depends on the number of dwellings affected, the effect on the capacity of the wind farm of meeting the standard, and the duration and level of exposure.

Wind turbines and wind farms have been being developed in Denmark for over 20 years. Denmark has set a base noise level only (and does not consider the influence of background noise). The base noise level (LAeq) is set at 40 dB(A) for a wind speed of V10m = 8 m/s. These guidelines will provide a similar result given the expected influence of background noise. …
— – — –

Where the wind farm sites are within or next to areas where more intensive activity is expected, the base noise level may also be increased commensurate with the amenity of that area. It is recommended that the developer discuss such a situation with the EPA and the relevant planning authority.

2.1 Determining wind farm operating criteria

The Environment Protection (Industrial Noise) Policy 1994 limits the noise level from non-domestic noise sources including wind farms to 40 dB(A) or the lowest typical background noise level plus 5 dB(A) (whichever is the greater) in rural areas from 2200 hrs until 0700 hrs the following day.

This limit applies to existing noise sources and does not necessarily reflect the preferred noise criterion for new (planning) development. The general approach for new development applies a night time level of 35 dB(A) to significant development in a rural location.

To prevent adverse impacts from the increased noise of WTGs under high wind conditions, the increasing noise level must also be compared to the corresponding background noise at the relevant receiver.

2.2 Noise criteria — new wind farm development

The predicted equivalent noise level (LAeq,10), adjusted for tonality in accordance with these guidelines, should not exceed:

· 35 dB(A), or

· the background noise (LA90,10) by more than 5 dB(A)

whichever is the greater, at all relevant receivers for each integer wind speed from cut-in to rated power of the WTG. …

2.5 Cumulative development

Separate wind farm developments in close proximity to each other may impact on the same relevant receiver.

Therefore, as for staged development, any additional wind farm that may impact on the same relevant receiver as an existing wind farm should meet the criteria using the background noise levels as they existed before the original wind farm site development. The noise generated by existing WTGs from another wind farm should not be considered as part of the background noise in determining criteria for subsequent development. …

3.1 Background noise

What is background noise?

Background noise is the ‘lull’ in the ambient noise environment.

Intermittent noise events such as from aircraft flying over, dogs barking, mobile farm machinery and the occasional vehicle travelling along a nearby road are all part of the ambient noise environment but would not be considered part of the background noise unless they were present for at least 90% of the time. …

4.4 Tonality

Where, in the opinion of an officer authorised under the Environment Protection Act, the wind farm exhibits tonality as a characteristic, the developer should conduct a tonality test in accordance with a procedure acceptable to the EPA.

An addition of 5 dB(A) should be made to the measured background noise level from a wind farm where tonality is shown to be a characteristic.

Download “Environmental Noise Guidelines: Wind Farms”

Download “Comments to the Moresville Energy Project DEIS” (large)

Download “Comments to the Moresville Energy Project DEIS” (small)