The Scale of Wind PowerPer US DOE (US Department of Energy)

According to the US Department of Energy, Wind & Hydropower Technologies Program, wind turbines fall in two categories:

Utility-scale turbines range in size from 100 kilowatts to as large as several megawatts. Larger turbines are grouped together into wind farms, which provide bulk power to the electrical grid.

Single small turbines, below 100 kilowatts, are used for homes, telecommunications dishes, or water pumping.

Source: http://www1.eere.energy.gov/windandhydro/wind_how.html

Current Wind TechnologiesSmall • Homes (Grid connected)• Farms• Remote Applications (e.g. battery charging,

water pumping, telecom sites)

Intermediate • Village / Farm

Power• Community Wind

Large• Wind Farms• Offshore Wind Generation

50kW EntegrityBlackwater USA

49.2’ diameter rotor100’ tower

Monopole version at Maple Honda

100kW Northwind 100 66’ diameter rotor

121’ tower

Small Wind Growth• “Small wind” defined as ≤ 100kW• 25 MW installed in U.S. in 2010,

making 179 total MW in U.S.• Significant shift away from micro

and off-grid systems to larger, grid-connected units

• 30% federal tax credit• 30 states with small wind

incentives• 1500 full-time jobs in small wind

On-grid vs. Off-grid trends

The U.S. market experienced a pronounced shift to larger,grid-connected systems.

Combining off-grid and on-grid sales, the average unit size has increased more than three-fold since 2007 (from 1.1 kW in 2007 to 3.3 kW in 2010).

2010 Small Wind Size Trends

Small Wind Manufacturers• The top three U. S. manufacturers in terms of

2010 capacity sales were Northern Power, Southwest Wind Power and Bergey Windpower.

• The average installed cost of small wind turbines sold in the U.S. in 2010 was $5,430/kW

• 9 of the top 10 models sold in the United States are grid connected.

• 9 of the top 10 are a three-blade design, 10 of 10 are horizontal axis turbines

Small Wind Workforce• 3 of top 5 small wind

companies are American

• Turbine manufacturing, tower manufacturing, transportation, installation, and education

• 30% of a turbine’s total cost is installation, most often involving local contractors

New for 2010-2011• 2010: Small Wind

Certification Council

• 2010: NABCEP Small Wind Installer Credential

• 2011: National Electric Code Article 694 for small wind generators

Small Wind Certification CouncilRated Annual Energy: assumes a universal, constant wind speed of 5m/s, a pure Rayleigh wind distribution (weibull k = 2) and gives a value for kWh/year.

Rated Sound Level: Value will not be exceeded 99% of the time, assumes a 5m/s wind, rayleigh distribution, and that the observer is 60m from the rotor. Gives a value in decibels.

Rated Power: Power output at 11m/s at standard sea-level conditions.