Mass High Tech: The Journal of New England Technology - June 23, 2006
by Richard J. Costello

With energy prices spiraling out of control, many businesses are searching for ways to reduce and control energy costs. It's a trend that is also fostering a great deal of interest in renewable-energy options. Wind power is the fastest growing alternative energy segment, providing an attractive cost structure relative to other alternative energy and distributed generation solutions, such as cogeneration and solar power.
However, the wind power market is dominated by large horizontal wind turbines -- the traditional blade design that looks like a giant fan -- clustered mostly on 'wind farms' located in rural areas. These large systems seriously compromise the ability for many companies to take advantage of wind power right at their building or plant. This is due to the economics of horizontal wind turbines that favor large units, multiple-megawatt installations and current technology dynamics.
However, new technology has come on line that breaks this model -- the vertical-axis wind turbine. It addresses a number of the technology's known shortcomings, such as noise pollution, minimum blade speed threshold, bird endangerment and space limitation, while enhancing its advantages.

System design

The vertical-axis design is a compact turbine design that can be sited on location without being intrusive and has been designed to be integrated directly into existing buildings. This size advantage allows structures as small as an office building or hospital, for example, to locate the turbine onsite.
Economically, onsite installations dramatically improve the ROI of wind power. Power generated offsite -- such as at wind farms -- is still subject to transmission and distribution charges. Conversely, onsite solutions take a portion of the organization power requirements "off the grid."

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Blade speed

A traditional horizontal blade design turbine of similar size requires a greater level of wind speed to generate power. The vertical axis turbines provide omni-directional wind collection, allowing it to make power while turning at slower blade speeds. One benefit of this feature is obvious -- it can work at locations with lower average wind speeds. Therefore the geographic options for using wind generation is greatly expanded; a company may not need to be located on a hilltop or in coastal locations to reap the benefits. Plus, it reduces wind direction limitations, as it can collect wind power on a 360-degree basis. Horizontal blade technology must spend time turning into the wind when the wind changes direction.

Environmental impact

The slower blade tip speed has environmental improvements as well. First, it is virtually silent when operating. Unlike traditional wind turbines, the vertical axis turbine has the blades connected at both ends, and the blades do not swing by the pole and create noise. Also, with no high-speed wing tips exposed, the vertical axis turbine has relatively low impact on bird populations.

Economic benefits

Traditionally, most renewable-energy projects relied on financial assistance from a host of mechanisms, such as production tax credits, renewable portfolio standards, green credits and government rebates. While these subsidies are still required for most renewable-energy resources projects, such as solar power, large wind, and hydro facilities, in projects using vertical-axis wind turbines the need for subsidies is greatly diminished. U.S.-manufactured vertical axis turbines are less expensive to obtain and implement.

In addition to purchasing turbines, some manufacturers will own and operate the turbines, selling organizations the green power generated onsite, at a guaranteed long-term fixed power rate. This can be a favorable alternative, enabling the organization to reap the economic benefits of "off the grid" power, without the financial risk.

In addition to compelling cost saving, the onsite turbine is a powerful demonstration to an organization's commitment to green power. Constituents can see the commitment, not just reading about it the annual report or mission statement.

Richard J. Costello is president of Norwood-based Acela Energy Group, an energy management and energy procurement firm. He can be reached at richard.costello@acelaenergy.com

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