Data
Technical Data (Nuts and Bolts)
Power Production
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source: American Wind Energy Association: link
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The rated energy output of a
turbine is expressed in terms of kilowatt hours (kwh) at rated wind speed,
meaning the number of kilowatts a turbine can produce in an hour. A turbine
only produces its rated output under optimal wind conditions. Optimal wind
conditions are anywhere between the rated wind speed, where the turbine reaches
maximum power output, and the cut-out wind speed, where the turbine's central
computer stops blade rotation to prevent damage to the turbine's mechanisms.
Wind conditions at any given site vary, however, and are
not constantly within a turbine's maximum power output range. The actual
yearly power output of a turbine depends on the site's average annual wind
speed.
source: American Wind Energy Association:
link
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Wind Resource
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The Minnesota Department
of Commerce Energy Division has been collecting wind data for decades. The
data is made publically available in the Wind Resource Analysis Report (WRAP).
This is the best source for physical data on wind, and includes enough detail
to be used by communities seeking information on wind in their area. It is
a key technical element for any wind project.
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WRAP data on wind can be converted
to reflect the power generation potential of wind, expressed in watts/square
meter. For an overview of Minnesota (4KB): link
source: WRAP, data from 1984-1993.
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WRAP data is also used to create
graphic representations of average wind speed. For an image of the wind resource
in the Northfield area (187KB) : link
The circled areas are possible turbine sites.
The site ultimately chosen was the ridge directly east of town, circled in
red. The middle school site was considered first. The Nerstrand site provided
baseline wind data.
source: WRAP, data from 1995-2001.
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Economic Data
A mix of federal
and state regulations forms a legislative framework impacting the economics
of wind energy in Minnesota. At present, Northfield's wind project is directly
affected by two incentive programs, run by the federal and state governments.
The incentive programs allocate government funds to qualified renewable energy
projects. Northfield's project can benefit from the federal Renewable Energy
Production Incentive (REPI), as well as the state Wind, Hydro, Digester Energy
Incentive.
The state incentive program pays 1.5cents/kwh to wind facilities
with a capacity under 2 megawatts (MGW). Because both Carleton and NSD will
install 1.5 MGW turbines, both will qualify for the state incentive. Current
legislation, however, places a 100 MGW statewide cap on the amount of wind
energy qualified for the incentive payments. Fortunately, a bill currently
in the state legislature would increase the cap to 250 MGW.
source: Database of State Incentives for Renewable Energy
(DSIRE): link
To follow the progress of
the state bill to raise the MGW cap, use the
Minnesotans for an Energy-Efficient Economy
(ME3) Legislative
Watch, and click on "House bill
No. 1333/Senate bill No.1205": link
As a governmental sub-unit, NSD qualifies for federal REPI
payments of 1.8cents/kwh. The REPI is currently up for reauthorization beyond
2003.
source: U.S. Department of Energy, Office of Energy Efficiency
and Renewable Energy:
link
To follow the
progress of the federal bill, use the Library of Congress
legislative information web site, Thomas. Run a search
on the
"Renewable
Energy Production Incentive Reform Act." link
Although incentive payments are extremely important for wind
energy projects, the feasibility of a project ultimately depends on the quality
of the wind resource at the chosen site. For Northfield's project, calculations
show that any site with a better wind resource than the Nerstrand wind monitoring
station (see WRAP image for Northfield area) would be profitable for the investing
institutions. Below is a graph comparing wind speed at the chosen Northfield
site (upper line) to the Nerstrand baseline data (lower line) for the month
of February.
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courtesy of Jeff Eckhoff, Assistant Principal,
Northfield Senior High
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A third
element of the economic feasibility of the RENew/NSD/Carleton project is the
financial situation and goals of the investors. Much of this information is
private. However, the investors and St. Olaf College ran hypothetical feasibility
studies before deciding to invest or, in St. Olaf's case, not to invest.
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To see a hypothetical feasibility study for
a typical college wind project
(53 KB): link
courtesy of Bruce Anderson, President, RENew
Northfield.
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To see a feasibility study for St. Olaf College,
assuming qualification for state incentive payments - contingent upon increasing
statewide MGW cap. (11KB): link
courtesy of Peter Sandberg, Director of Facilities
and Special Assistant to President, St. Olaf College.
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To see a feasibility study for St. Olaf College,
assuming non-qualification for state incentive payments - 100MGW statewide
cap maintained. (11KB): link
courtesy of Peter Sandberg.
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Narrative Data
Narrative data was gathered through interviews with community members,
and from the results of an independent professional survey of Northfield
School District residents. The interview list, with links to summaries, preceeds
a presentation of the survey. Three sections of the "executive summary" are
quoted.
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Interviews
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RENew Northfield
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Northfield School District
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Carleton College
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St. Olaf College
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Elected Officials
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Bruce
Anderson - President
summary
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Jeff
Eckhoff - Assistant Principal, Northfield Senior High
summary
Kate Huber - Sophomore, Northfield Senior High
summary
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Richard
Strong - Director of Facilities
summary
Alyssa Thomas - Environment and Technology Studies (ENTS)
Intern
summary
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Peter
Sandberg - Director of Facilities and Special Assistant to the President
summary
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Molly
Woehrlin - Former County Commissioner
summary
Keith Covey - Mayor of Northfield
summary
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2003 Northfield Public
School District Pre-Referendum Study
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"Methodology:
Decision Resources, Ltd., contacted three hundred randomly selected residents
of the School District by telephone between February 26th and March 5th,
2002. The non-response rate was less than five percent. The typical respondent
took twenty-one minutes to complete the survey. Results of the study are
projectable to the entire adult population of the Northfield School District
within + or - 5.5% in 95 out of 100 cases."
"School District Wind Energy Turbine:
By an 80% - 6% super-majority, residents favored the construction of a wind
energy turbine by the School District. In fact, forty-five percent "strongly
favored" its construction. And, while nineteen percent supported its construction
whether energy savings took place or not, sixty-four percent would support
the project if it would save the School District a moderate amount of energy
expense over a reasonable amount of time."
"Conclusions:
5. Residents were overwhelmingly supportive
of the construction of a wind energy turbine, particularly if it will save
a moderate amount of energy expense over a reasonable amount of time."
source: Decision Resources, Ltd.
Northfield Public Schools
Study
March, 2003
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