Vermont Proposes Turbine Sound Rules ‘Ostracizing’ Wind Industry

Betsy Lillian
Written by Betsy Lillian
on May 18, 2017 1 Comment
Categories : Featured, Policy Watch

The Vermont Public Service Board has rolled out a new proposal for standards regarding wind turbine sound levels – which some fear could hinder the future of wind energy in the state.

According to the Public Service Board, a June 2016 law required the board to adopt turbine noise rules before July 1 of this year. Following a request for proposals, several workshops and hearings, and public-comment periods, the final proposed rule was submitted to the Secretary of State and Legislative Committee on Administrative Rules this week.

Under the final proposal, projects cannot exceed 42 decibels (dBA) “more than five percent of the time at a distance of 100 feet from the residence of a non-participating landowner.” However, for projects more than 150 kW, the level is set to 39 dBA between the hours of 9:00 p.m. and 7:00 a.m.

The board notes that it had originally proposed a level of 35 dBA for nighttime operations, but due to “well over 100 comments” stating that this level would be “too restrictive,” it was upped to 39 dBA.

In addition, the board has proposed a setback requirement for larger wind turbines: “[A]ll turbines and sound-producing equipment located within the footprint of the turbine array [must be] a horizontal distance of at least 10 times the height of the turbines – with a blade tip in its vertical position – from the nearest residence of a non-participating landowner.” In other words, if a turbine measures 500 feet, it would have to situated 5,000 feet from a residence – i.e., nearly a mile away.

For turbines more than 150 kW, developers must follow the setback requirement and demonstrate via post-construction monitoring that the project is in compliance with the sound rules. For turbines 50 kW-150 kW, developers must either follow the setback requirement or conduct post-construction monitoring.

However, the rule makes things less stringent for developers with turbines up to 50 kW in capacity:

“For these turbines, there is no minimum setback requirement or a requirement for sound monitoring post-construction. Instead, petitions for small turbines must include certain certification documents regarding the sound levels produced by these turbines and a simplified demonstration that sound pressure levels at the closest residence will be within the applicable limit.”

In addition, “with respect to setbacks for large turbines,” the board says, it plans to offer a waiver system to allow for facilities to be situated closer to residences – as long as the developer can prove the turbine “would meet the applicable standards at a lesser distance due to unique terrain features or future improvements in turbine technology.”

Renewable Energy Vermont (REV), which says the rule could “effectively ban future wind energy generation in Vermont,” points out decibel levels for common noises. According to the group, a “soft whisper” is measured at 30 dBA, and rainfall or a refrigerator is measured at 50 dBA.

REV also argues that the “unprecedented standards are not grounded in peer-reviewed science” and that they set an “impracticable and lower sound level than any other state and Canada.”

“We could power more than half of Vermont’s homes with cost-effective wind energy and grow our economy – but not under these proposed rules,” the group says in a statement. “The latest proposed regulations set unreasonable requirements on farmers and landowners interested in helping lower our electricity costs with pollution-free community and utility wind projects.”

The group cites Vermont resident Esther Weber, who lives one mile from the Kingdom Community Wind Project, as being a big wind fan and not taking issue with the noise:

“I love the wind turbines. All my life I’ve thought, ‘How wonderful it would be if we could harness our natural resources to produce energy,’ and I was so thrilled when I heard there will be wind towers on our mountain … It’s a big bonus to have tax relief, and it’s a bigger bonus to have them on the mountain doing good … You have to listen hard to hear them at all.”

In a public comment made on May 11, Waitsfield, Vt.-based Aegis Renewable Energy Inc. argued that the rule “ostracizes the wind industry by requiring wind turbines to operate at much lower sound levels than the majority of existing infrastructure in Vermont.”

“For example, gravel pits/quarries, roads, railways, dams, transmission substations, farms, saw mills/firewood processing plants, landfills, marinas, airports, manufacturing plants, and automobile mechanic shops operate at sound levels louder than 45 decibels. It is unreasonable to treat wind turbines differently than the above-listed infrastructure,” the company wrote.

However, in its own comment on the proposed rule, the board maintained that the rule is “appropriately protective of the quality of life for Vermonters who must live near wind facilities that are sited in their communities.” In particular, the board believes the siting requirements “reflect appropriate consideration of the aesthetic impacts of the sound emissions from wind generation facilities, particularly in light of the rural character of Vermont.”


  1. Cape Cod Commission Wind Turbine Setbacks 10X Massachusetts

    Cape Cod Commission –Wind Turbine Update April 2011

    Example : Each blade is 150 feet long plus the nacelle . The total diameter is over 300 feet. 10x the diameter is 3000 feet .

    “MPS E1.8 – NoiseAll Applicants for a WECF greater than 660 KW shall perform a noise study and fund a Cape Cod Commission approved consultant’s review of the noise study, and adhere to a setback of 10 times the rotor diameter of the proposed turbine from the nearest receptor, or residentially zoned parcel,”

    Approved Amendments to Regional Policy Plan
    Assembly of Delegates
    April 20, 2011

    Minimum Performance Standards for Energy
    MPS E1.7 – Clear Area
    All WECFs shall maintain a Clear Area surrounding the base of the turbine equal to at least 1.5 times the height of the WECF, or the WECF manufacturer’s fall zone, setback, or clear area specification, whichever is greater. The Clear Area setback shall be measured from the base of the turbine.
    MPS E1.8 – NoiseAll Applicants for a WECF greater than 660 KW shall perform a noise study and fund a Cape Cod Commission approved consultant’s review of the noise study, and adhere to a setback of 10 times the rotor diameter of the proposed turbine from the nearest receptor, or residentially zoned parcel, unless the applicant can demonstrate through a noise study, to the satisfaction of the Cape Cod Commission, that the projected sound levels, including both ambient and infrasound, would result in minimal impacts to occupants within a reduced setback. All DRIs shall, after consulting with the Commission’s noise consultant, prepare a plan which specifies reduced operating procedures, including decommissioning plans, which address and mitigate noise complaints that may arise during operation of the WECF. Components of a noise study can be found in Technical Bulletin 11-001.
    MPS E1.9 – Shadow Flicker
    All Applicants for a WECF shall conduct an impact study of shadow flicker on receptors which will be affected by the proposed WECF. All DRIs with shadow flicker effects on receptors shall require the Applicant to submit for review and approval by the Commission a mitigation plan which specifies operational controls, landscaping, or other means that mitigate shadow flicker events to less than 10 hours per year.
    MPS E1.10 – Decommissioning
    Any WECF that has not been operational for more than 120 consecutive days shall be dismantled and removed from the site by the owner, operator, and/or other parties as designated by the decommissioning plan unless a written waiver is obtained for good cause shown from the Cape Cod Commission’s Executive Director. The Applicant shall also provide security in a form and amount satisfactory to the Cape Cod Commission. The security shall cover over the life the WECF the cost of decommissioning and removing any abandoned or damaged WECF. This security shall be in place and payable to the Town or Commission on demand for the life of the WECF. All WECF DRI decisions shall contain a written decommissioning plan, which also addresses removal of the meteorological (or “met”) tower.
    MPS E1.11 – Municipal WECF Waiver
    Because of the procedural, legal and political safeguards applicable to town appropriations and the use of town-owned land, Minimum Performance Standards E1.8 – E1.10 shall not apply to one Municipal WECF 250 KW or less on a single parcel.
    Proposed changes to other sections of RPP
    HPCC 2.3 – Avoid Adverse Visual Impacts: New Development shall be sited and designed to avoid adverse impacts to visually sensitive areas, including those protected by HPCC 1.1 and 1.2. Visual impact assessments may be required as part of the project review. Development proposed adjacent to scenic roads or vistas shall preserve distinctive features of the scenic resource including tree canopy, wooded road edges, stone walls, winding road character, and scenic views. Development adjacent to or within scenic vistas shall be clustered and designed to limit the visibility of the new development.
    (Note: All definitions to be added to RPP. Those added to Enabling Regulations only denoted with *)

    WECF* – All equipment, machinery and structures utilized in connection with the conversion of wind to electricity. This includes, but is not limited to, all transmission, storage, collection and supply equipment, substations, transformers, site access, service roads and machinery associated with the use. A wind energy conversion facility may consist of one or more wind turbines, and does not include meteorological (or “met”) towers.
    Clear Area – Area surrounding a WECF to be kept free of any structure designed for human occupancy.
    Shadow Flicker – Alternative changes in light intensity caused when rotating turbine blades come between the viewer and the sun, causing a moving shadow.
    Meteorological (or “met” or “test”) Tower* – Tower used for supporting anemometer , wind vane and other equipment to assess the wind resource at a predetermined height above the ground.
    Municipal Wind Energy Conversion Facility – Any WECF proposed, owned and operated by a municipality.
    Height of a WECF – The distance from the pre-development natural grade of the site of the proposed WECF to the highest point of the structure, including any moving part which is a component of the WECF.
    Road – A public or private way, other than a driveway servicing only the property which is proposed as the site of the WECF.
    Receptor – A dwelling, or any non-residential structure which is designed and/or utilized for human occupancy.

    DOC]1-6-11 Wind DRI Thresholds & RPP MPSs (A0836896-2).DOC
    Apr 20, 2011 – Minimum Performance Standards for Energy … study and fund a Cape Cod Commission approved consultant’s review of the noise study, and adhere to a setback of 10 times therotor diameter of the proposed turbine

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