Petition of Deerfield Wind, LLC for a Certificate of Public Good …
January 8, 2007
II. Description of the Project
B. Wind Resource and Energy Production
11. More than two decades of wind data gathered in the site area provide confidence in the longterm average wind resource and the energy production estimates derived from it. The capacity of the Project will be up to 45 megawatts, depending on the size and number of turbines (1.5 to 3.0 MW each).
12. Based upon the estimation of wind speed, and accounting for blade icing/fouling, cold temperature shutdown, turbine availability, array losses, high wind factors, electrical losses, and a margin for uncertainty, the expected long-term annual net energy production from the Deerfield facility is approximately 120,000 megawatt-hours (+/- 10%, depending on the number and type of turbines). The expected capacity factor is 0.35 (+/- 10%, again depending upon the turbines selected).
120,000 MWh / 8,760 h/yr = 13.7 MW, which is 0.30 of 45 MW, NOT 0.35. The existing Searsburg turbines promised a similar output but have proved to average only around 21%.
C. Wind Turbines and Related Equipment
13. Each wind turbine is comprised of three components – the tower, the nacelle, and the rotor blades. The turbines use a tubular steel tower, approximately 260 feet in height and 16 feet in diameter at its base. The tower is topped by a nacelle, which houses the main mechanical components of the turbine. The rotor, mounted on the nacelle, consists of three fiberglass blades up to approximately 148 feet to the center of the hub. The total height of the turbines (highest arc of the rotor blades), depending upon the turbine model ultimately chosen, will be up to 125 meters (410 feet) above the turbine base.
This appears to be the Vestas V90, which is available with a 1.8-MW or 3.0-MW generator.
15. The wind turbines begin generating energy at wind speeds as low as 9 mph and produce full power at wind speeds above 30 mph. The maximum rotor speed is approximately 20 revolutions per minute.
The maximum rotatinal rate of the 3-MW Vestas V90 is 19 rpm, and its rated wind speed is 34 mph (15 m/s), NOT 30.
Note that the swept area of the blades is 1.57 acres, and the maximum speed at the tips is 200 mph.
16. The turbine structures will be anchored to a concrete foundation. An area of the concrete foundation approximately 18 feet by 18 feet will be left exposed. The wind turbines will be sited a minimum of about 2.5 rotor diameters apart.
22. Land clearing and harvesting of trees will be done for the turbine installation and for the road construction described above. No more than 80 acres of National Forest land will be occupied for the installation of the wind turbines. Clearing will be done in linear strips, with small areas approximately one acre in size cleared out along the ridge-top portions of the roadways around the base of each individual turbine.
For 15 turbines, that’s 5.33 acres around each one. The loss of interior forest habitat extends a further 250-300 feet, for a total of more than 20 acres per turbine.
F. Operation and Maintenance
27. The Project will operate for approximately 30 years. Operation and maintenance will be in accordance with a plan that will include a centralized Supervisory Control and Data Acquisition (SCADA) system to monitor the condition of the wind plant equipment, alert service technicians to any fault or alarm conditions, record and sort data, and allow remote control of the turbines.
28. Maintenance of the wind turbines, transmission facilities, and site improvements (roads, gates, fences, etc.) will generally be scheduled in two inspections at approximately six-month intervals and averaging 40 to 50 person hours per year for each turbine.
29. The Project will require 3 to 5 permanent staff for on-site operations.
30. Access to the Site will be controlled. Public access will be limited in accordance with the conditions established in the Special Use Authorization issued by the Forest Service and state permitting procedures. Access will be controlled with gates.
32. At the end of the Project’s useful life or the loss of permission from the Forest Service to maintain the facility, decommissioning will occur. Decommissioning will be paid for out of a fund established by Deerfield Wind.
33. Decommissioning will include removing all buildings, structures, and other above ground equipment on federal and private land, with the exception of non-wind turbine components that landowners request remain in place (access roads, buildings, etc.). Turbine foundations, poles, and insulators will be removed to a minimum depth of 3 feet.
That is, the steel-reinforced concrete bases will remain.
III. SECTION 248 CRITERIA
B. 30 V.S.A. § 248(b)(2) – Need for the Project
43. The Project “is required to meet the present and future demand for service which could not otherwise be provided in a more cost effective manner through energy conservation programs and measures and energy efficiency and load management measures…” The Project meets a present and future demand need for cost effective electricity in Vermont and in the New England Power Pool.
As a part of the New England power grid, this project – at an average output of 30%, i.e., a total annual output of 120,000 MWh – would represent less than 0.1% of the system’s total production (135,000,000 MWh in 2006). At a more likely average output of 21%, the project would represent only 0.06% of ISO New England’s production. Obviously, conservation could easily and economically reduce the need for that small amount of additional energy.
48. It is in the public interest to increase fuel diversity. Over the past decade, the major trend in the mix of fuels used for electricity generation in New England has been the shift toward natural gas from nuclear and oil.
49. Demand for natural gas has grown from all sectors, and this demand growth has led to rising gas prices and to more volatile prices. Rising and more volatile gas prices will make wind energy more valuable, because higher average gas prices raise average wholesale electricity costs, increasing the value of energy produced by wind projects. In addition, because the costs of a wind project are not affected by fluctuating fuel prices, they are much more stable than the costs of generation with gas or oil.
Efficiently balancing of the intermittent and highly variable energy from wind requires more natural gas plants, not fewer, because they are the ones able to respond quickly enough.
C. 30 V.S.A. § 248(b)(3) – System Stability and Reliability
51. The Project “will not adversely affect system stability and reliability,” either locally or regionally.
That’s because on the New England grid, its contribution would be so very small (less than 0.1%).
D. 30 V.S.A. § 248(b)(4) – Economic Benefit to the State
58. The Project is a renewable energy project that will not produce air emissions from the generation of electricity, including NOx, SO2, and CO2. Energy production at this Project will likely displace higher cost power that is supplied by a fossil-fueled generation plant that does emit pollutants. An economic analysis calculated a projected annual benefit of between $0.6 million and $1.1 million in avoided external costs due to displaced conventional generation, depending both on project size and on the valuation model.
Missing from this analysis is the the actual behavior of other plants in balancing the fluctuating infeed from wind. Many plants will continue to burn fuel to stay warm on standby; others may require more fuel for more frequent restarts. The fuel thus burned may be burned less efficiently, i.e., with more emissions. Displacing electricity is not the same as reducing fuel use or emissions.
59. The cost of project construction is expected to be about $2 million dollars per installed megawatt.
And what would the cost be of mitigating the need for such a project? Much much less. 25,000 compact fluorescents could save the need for each installed megawatt of wind power – without sacrificing any forest habitat.
E. 30 V.S.A. § 248(b)(5) and (8) – Environmental and Other Considerations
2. No Undue Air Pollution
65. The Project is expected to result in sound levels at the nearest residences of 45 dBA or less. Noise levels from the turbines will be at or below average background noise levels that occur at permanent or seasonal residences. No local applicable, state, or federal noise standards or guidelines would be exceeded.
103. The Project is expected to result in sound levels at the nearest residences of 41 dBA or less. Noise levels from the turbines will be at or below existing average background noise levels that occur at permanent or seasonal residences. No local applicable, state, or federal noise standards or guidelines would be exceeded.
They are obviously just pulling numbers out of thin air. Both 45 and 41 dBA, as well as the contradictory claim that such a noise level would be at or below the background levels. At night, the sound levels at nearby residences are likely to be in the low 20s, and a noise in the low 40s would be perceived as four times as loud. Note that the “A” weighting ignores low-frequency and infrasonic noise.