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An Overview of Small Wind Energy Today
Shawn ShawThe Cadmus Group, Inc.www.cadmusgroup.com
Sierra Club Northeast Committee Fall Energy Conference10/12-10/14/2007
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The Cadmus Group
• Environmental Consulting firm specializing in energy, drinking water, and risk management
• Based in Watertown, MA• 150+ employees worldwide
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Clean Energy Practice
• Field inspections of renewable energy systems– >50 small wind inspections to date– >100 PV inspections to date
• Program support and production tracking for state renewables programs
• Renewable energy program evaluation• Energy efficiency in appliances and
buildings
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“Small” Wind?
• Mostly 10 kW or Less• Mostly 80-120 ft Tall
100 ft Tower
7 ft Blade Length
200-300 ft Tower
100 ft Blade Length
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Why Small Wind?
• Reduce energy costs• Help the environment• Make a statement• Backup power
– Need batteries
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A Typical Wind Energy System
Wind Turbine
Home Circuit breaker box
& Utility net meter
Controller, inverter
The “grid”
DC AC
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Factors Affecting Energy Output
• Available Wind Resource• Site Conditions/Terrain• Tower Height
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Assessing the Wind Resource for Small Systems
• Wind maps• Local clues
– Tree flagging– Nearby weather stations
• Airports• Schools
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Spotting a Potential Site
• “Flagging” vegetation
• Constant breeze• Bodies of water• Open terrain• Slope
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The Wind Resource in Southern New England
Good wind resource in coastal areas and mountainous regions
•Cape Cod
•Berkshires
•Martha’s Vineyard
Look for wind speeds > 5 m/s at 30m for good small wind potential
10% difference in wind speed ~ 33% more energy!
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The Importance of Wind SpeedSmall Wind Cost Effectiveness in a Typical Inland Site with
Moderate Obstructions
$0.00
$0.20
$0.40
$0.60
80 ft 100 ft 120 ft
10 kW
$/kW
h
Low (4.5m/s)
Med (5.25 m/s)
High (6 m/s)
PV Cost Effectiveness (10 kWDC): $0.38/kWh
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Obstacles Create Turbulence and Reduce Apparent Wind Speed
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Site Conditions Affect Energy Production
Impacts of Terrain on a Typical 10 kW Wind Energy System
0 5,000 10,000 15,000 20,000
Coastal/No Obstructions
Coastal/Some Forest
Inland/Moderate Forest
Inland/Heavy Forest
Open Farmland
Inland Suburban
Annual Energy Produced (kWh/year)
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Good Site Characteristics
• Open access to prevailing wind• >100 ft from neighbors• Downward sloping terrain• Bodies of water• Close to electrical interconnection
point
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The Importance of Tower Height for Non-Ideal Sites
0
2,000
4,000
6,000
8,000
10,000
12,000
80 100 120
Turbine Hub Height (ft)
An
nu
al
En
erg
y O
utp
ut
(kW
h)
MTC MinimumRequirement
Assumes: 6 m/s wind speed at 70m, rough terrain, 50 ft surrounding trees, 10 kW Bergey Excel-S turbine used for example calculations
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Basic Small Wind Economics
• 10 kW System, good site, 100 ft tower, utility interactive (no batteries)– 15,000 kWh/yr– $3,000/yr revenue– Installed Cost: $60,000– MTC rebate: $22,500 (example)– Simple Payback: 12.6 yrs– System Lifetime: 20+ yrs
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The Small Renewables Initiative
• Provides incentive for residential scale renewable energy projects (up to 10kW)
• Covers solar PV, wind, and small hydro projects
• Approximately $3.6M available annually
http://www.masstech.org/RenewableEnergy/small_renewables.htm#
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SRI Rebate Matrix
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SRI Small Wind Requirements
• Follow all applicable codes/standards• Hub height must be 30+ ft above all
surrounding obstacles• Estimated capacity factor 10%+• All new equipment• Wet stamped engineering plans• Inspected/approved by Code officials
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Other Incentives/Programs in the Northeast
• Incentives/Rebates in:– New York– Massachusetts– Vermont– Delaware– Maryland– New Jersey
• Tax Exemptions/Credits in:– Massachusetts– Maryland– Rhode Island– Vermont
• Proposed federal tax credit in House and Senate– HR 1772 and 2776– S. 673– $3,000 per kW tax credit for small wind systems
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Small Wind Applications
• Schools• Farms• Homes• Businesses• Public buildings• Remote areas
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Environmental Benefits of Small Wind
16,000 lbs CO2/Yr2 Acres of Forest
Planted1 SUV Taken Off the Road
10 Tons of Coal/Yr Not Burned
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Small Wind: An Ally Against
• Habitat loss• Groundwater pollution• Climate change• Power plant emissions
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Impacts of Small Wind Turbines
• Wildlife• Land area• Noise• View shed
Little impact from small wind systems
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Small Wind Walks on the Wild Side
Even a 100 fold increase in the use of wind power would produce less bird deaths than our current use of communication towers and similar structures.
Small wind turbines are no more likely to harm birds than any other ~100 ft structure.
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But Doesn’t Wind Take A Lot of Space?
• Typical footprint of a residential wind installation: <100 s.f.
0
2
4
6
8
10
12
14
Coal Natural Gas Nuclear Wind
Acr
es/B
illi
on
kW
h
Source: Pace University, Environmental Costs of Electricity, 1991
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Wind Turbine Noise
• Noise levels (dB) from wind turbines drop off rapidly with distance
• Typically, 100 ft from tower base, turbine cannot be heard over ambient noise
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Scenic Impacts
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Regulating Small Wind Turbines in Massachusetts Communities
MA Towns Having Draft or Complete Bylaws for Small Wind Turbines•Brewster•Carver•Fairhaven•Freetown•Harwich•Marion•Sandwich•Others under development (e.g. Westport, Dartmouth, Russell)
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Regulating Small Wind Turbines: Points to Consider
• Setback from property lines/structures
• Maximum height• Visibility/noise• Engineering requirements• Zoning restrictions
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For More Information on Small Wind
• Paul Gipe’s books www.chelseagreen.com • AWEA, small wind turbine section
– www.awea.org/smallwind/toolbox/default.asp • Home Power magazine www.homepower.com • Mick Sagrillo’s Videos and articles
– (writes for Home Power magazine, etc.)• Equipment Mfrs, e.g. Bergey, Southwest, Abundant (ARE)• Qualified models:
– www.consumerenergycenter.org/cgi-bin/eligible_smallwind.cgi – www.powernaturally.org/Programs/Wind/qualified_wind.asp?i=8
• http://www.windustry.com/resources/small-scale.htm • Interstate Renewable Energy Council & their Small Wind Web
Site irecusa.org/smallwindenergy/index.html • Canada has a useful site:
www.smallwindenergy.ca/en/SmallWind.html • Current Bills in Congress of Interest to Wind Energy
http://capwiz.com/windenergy/issues/bills/
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Small Wind as Part of a Climate Change Solution for the NE
• We can’t put up wind farms everywhere
• Solar PV is not always a good option
• Buying RECs provides no financial payback
• Significant environmental benefits
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What We Can Do to Bring More Small Wind to the Northeast
• Promote sensible bylaws and good installation practices
• Support tax credits to improve project economics
• Educate communities about the real benefits and impacts of small wind power
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