Has small wind’s time come?

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The U.S. market is prospering, and certification of small wind turbines is beginning

Should you install a small wind system for a building or development? In some cases, this alternative energy system is starting to make sense.

The U.S. market for small wind energy systems is prospering. According to an American Wind Energy Association (AWEA) report, it expanded 15% in 2009 and accounted for about half of the units sold in the entire world. Small wind systems are defined as those with rated capacities of 100 kilowatts (kW) or less, and are used primarily to power individual homes, farms, and small businesses.

See video of Ron Stimmel.

“Federal and state incentives now make it much more affordable to invest in a small wind turbine, and the market expanded in 2009 thanks largely to those incentives, optimistic investors, and popular demand,” said AWEA Manager of Small Wind Systems and Legislative Affairs Ron Stimmel, author of the report. “We’ve also seen domestic manufacturing investment grow, with nine small wind turbine production facilities opened or expanded in the U.S in 2009. The U.S. small wind turbine market is by far the world’s largest, both in terms of installations and of manufacturing.”

According to the AWEA, there were approximately 250 companies worldwide that manufacture, or plan to manufacture, small wind turbines in 2009. Ninety-five of them are based in the U.S., up from 66 in 2008, and at least 12 of the U.S. companies have begun to sell their turbines commercially. The vast majority of the world’s wind turbine companies are in start-up phases, and roughly half the world market share is held by fewer than 10 U.S. manufacturers.

It’s generally accepted that a small wind system makes sense in rural and off-grid applications where the wind is free from interference from a city’s structures. Even on top of very high buildings, the wind flow is turbulent, and today’s turbines need a strong laminar flow to work well.

The World Trade Center in Bahrain was the first skyscraper to integrate wind turbines in its design. Three 1,200-megawatt units are suspended between its 787-foot office towers.

Architects have taken on this challenge and have begun to design buildings that enhance wind turbine performance and adding wind scoops to their designs. And turbine manufacturers are taking advantage of buildings’ designs, manufacturing turbines that work with the increased wind velocities at a building’s parapets where the wind rises up to the façade and curls over the edge.

According to AWEA’s Small Wind Turbine Global Market Study, 187 units were reported sold for used in urban/rooftop settings in the U.S. in 2009, representing 400 kW of installed capacity and less than 2% of the U.S. market. Most of the building-mounted models manufactured today are a vertical-axis configuration.

Generally, the report concludes, “building-mounted installations face challenging performance obstacles due mainly to the turbulent and unpredictable nature of winds around buildings and other structures. Any turbine installed in a location or manner that limits its access to the wind resource will render its performance (i.e., output, measured in kilowatt-hours) below that of a turbine installed in an area where there is a robust, consistent wind resource. A small number of companies are working to address the difficulty of siting building-mounted turbines by using software and other computer models to predict wind resources more accurately in these environments. To date, however, siting and performance challenges have severely limited the size and potential of the market for building-mounted turbines.”

In spite of the challenges for building-integrated small wind energy systems, interest is high. A wind turbine can be a beautiful feature on a building, although unlike many other decorative elements, a wind turbine can be productive. For some, it’s a way of advertising a building’s greenness, although if the blades aren’t spinning, the message can be lost.

Hybrid wind and solar or wind and diesel systems are proving popular in remote locations.

Many small wind energy systems are hybrid installations with photovoltaics or diesel. “Hybrid systems using both wind and diesel generators, usually for remote applications, continue to be an important part of the commercial / light industrial market,” the AWEA report says. “In 2009 approximately 20% of turbines 50-100 kW were sold for wind-diesel hybrid systems, nearly all of which were in Alaska.”

Currently available tax credits and rebates are strong motivators to install a small wind energy system. The AWEA report estimates price ranges for a well-sited small wind turbine to gravitate between $3 and $6 per watt, and $0.15 to $0.20 per kilowatt-hour.

Costs and cost-recoupment periods can vary due to the following factors, ranked in approximate order of importance in the report:

  • Availability and quality of state incentives and state/utility net metering policies
  • Average annual wind speed
  • Prevailing costs of traditional electricity. Installations tend to be most cost-effective in regions where the cost of utility-provided electricity exceeds $0.10 per kWh.
  • Cost of equipment, installation, and maintenance.
  • Estimated operations and maintenance (O&M) costs average $0.01 – $0.05 per kWh. Other calculation methods place O&M costs at roughly 1% of the retail cost of an installation, accrued annually
  • Sales and property tax rates (and incentives)
  • Raw manufacturing materials
  • Insurance
  • Method of financing
  • Permitting costs, which can range from $0 to $1,000+ depending on the zoning jurisdiction
  • Application type. Installations for businesses may benefit from special tax incentives.

Certifying turbines

Performance data on this new technology is sparse. Enter the Small Wind Certification Council (SWCC), a brand-new, independent certification body, that certifies that small wind turbines meet or exceed the requirements of the AWEA Small Wind Turbine Performance and Safety Standard.
In December 2009, AWEA finalized a technical standard that can now be used voluntarily to test small wind systems to performance and safety criteria which meant that third-party organizations like the SWCC can now certify systems tested to this standard.

This certification provides a common North American standard for reporting turbine energy and sound performance, and helps small wind technology gain mainstream acceptance. Thirteen companies have applied for certification with SWCC, which SWCC says will take at least six months. It expects the first companies to be certified sometime in late 2010. The DOE and EPA indicate they will rely heavily on SWCC certification when granting selective Energy Star labels to qualified equipment. See related story, “Small Wind, Big Breakthrough.”

Certifying installers

The North American Board of Certified Energy Practitioners (NABCEP) plans to begin the process of certifying small wind turbine installation professionals in the fall of 2010. This voluntary program aims to offer experienced installers an opportunity to identify and market themselves as experts in their field. Installation is an important factor in a turbine’s performance, cost, and public acceptance.

Consumer demand continues to be fueled by a combination of the following factors listed by the AWEA, although economics and environment remain primary concerns:

  • Economics
  • Length of payback period, or IRR*
  • Financial hedge against rising prices of conventional electricity
  • Financial stability compared to volatile prices of conventional electricity
  • Practicality
  • Reliability of electricity supply
  • Natural synergism with solar PV technology
  • Diversity of applications, including those remote and off-grid
  • Values
  • Environment
  • Independence
  • Image enhancement
  • Consumer choice
  • Self-reliance
  • Do-It-Yourself
  • High visibility, particularly for commercial consumers
  • Drivers Specifically For Real Estate Developers
  • Marketability of a “Zero-Energy Home”
  • Practicality of integrating small wind and solar hybrid systems
  • Possible availability of rebates for both developers and consumers
  • Whether installation cost can be built into the price of a property
  • Role in defining the progressive character of neighborhood
  • Appeal of “renting vs. owning” electricity

Case studies:

Cincinnati Zoo

Pearl River

Boston Science Museum

St. Olaf Wind Turbine Case Study

McKee Park

Southwest Windpower case studies

Kansas Small Wind Projects

Wisconsin village installs two wind turbines at wastewater plant

Related stories:

Small Wind, Big Breakthrough


AWEA Small Wind Turbine Global Market Study 2010

How to install a small wind system

DOE’s Small Wind Guide

How wind turbines work


An introductory webinar on how a small-scale wind energy system works, what is the most suitable solution in your case and, if it makes sense, how to start planning and building your installation, with a case study using the RETScreen analysis software.

Posted by on Thursday, September 2nd, 2010. Filed under Technology. You can follow any responses to this entry through the RSS 2.0. Both comments and pings are currently closed.

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