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Advanced solution for harnessing light winds
The low energy efficiency of small wind turbines has been one of the main barriers to wider utilization of this kind of turbines in distributed power production. Eagle Windpower Oy, a Finnish technology company, has addressed this challenge by developing an awarded solution that utilizes nanotechnology in its blades. Carbon nanotubes make the blades stronger and lighter and improve energy efficiency.
Distributed energy solutions are especially valuable in emerging economies due to the fact that power grids are unreliable and electricity can be cut off hours each day. Small turbines can also provide power for remote villages and help to supply water.
Today, more than 2 billion people around the world live without electricity, and 1.6. billion without reliable water supply. Several million households worldwide are able and willing to spend USD150 per year for reliable energy, according to the World Bank.
Since ancient times wind power has been used in farms to pump water and grind grain. Now Eagle Wind Power brings wind back as the personal energy source for anyone. In 2008 Eagle has awarded three separate major prizes for its technology and products.
Nanotechnology – the key for efficiency
Eagle uses in its windmill blades carbon nanotubes and epoxy that binds the nanotubes. The epoxy has been used successfully e.g. in yacht manufacture and in sports equipment manufacture.
As a result, the blades are approximately 50 percent lighter than competing glassfiber blades. The blades are also stronger, due to the fact that carbon nanotubes are 100 times stronger than steel. The light weight of blades allows to increase the blade size.
“The energy provided by a wind turbine is square of the length of the blade. Thus, our blades can produce more energy and start operating at low wind speeds of 2 - 2.5 meters per second,” says Juha Siitonen, Managing Director of Eagle Windpower Oy.
"The material enables the doubling of the station’s wing size and an increase in power production of 30 percent, when compared to traditional small wind power stations."
Traditionally, turbine blades have been manufactured and coated manually. Eagle owns proprietary manufacturing technology to automate the manufacture of the wind turbine blades.
"The manufacturing technology is proven in ski manufacture. This, for its part, brings cost-competitiveness to our wind turbines," Siitonen says.
Eagle small wind power stations range from a 2kW model to stations producing up to 20kW. The turbine is positioned on a tower which is from 20 to 60 feet tall depending on the location. In the smallest house model the wings are 7 feet long.
An integrated generator coming
Eagle is co-developing a integrated generator solution which can fully use the low weight of Eagle's wind turbine blades.
The axial flux generators will reduce the weight of the generator and minimize energy loss. These type of generators have already been proven in industrial use.
Electrical on-grid transformer feeds the wind electricity directly into the households electrical network. During low wind days the extra energy required is taken from the electricity company’s grid.
On high wind days the excess production is fed into to electricity company’s networks and it is even possible to earn money by selling electricity back to the grid.
If grid connection is not available the off-grid controller stores the energy in batteries that balance the load and offer backup for low wind days.
New boost for small wind
The global wind industry installed approximately. 20,000 MW of new wind capacity in 2007. This resulted in the worldwide total of 94,000 MW
The increase was 31 percent compared with 2006, and an overall increase in global installed capacity of about 27 percent. The top five wind power markets are Germany, US, Spain, India and China.
The small wind turbine market has grown from estimated USD3.8 million per year in total sales internationally between 1984-1989, to estimated USD24 million per year in 1997.
Since 1997 the annual market growth has been estimated to have been 40 percent, resulting in an estimated market size of USD150 million/year in 2002, according to Garrad Hassan consultancy, UK.
According to Miamari Siitonen, Marketing Director, Eagle Windpower Oy, the small wind segment of the market has since 2003 not grown as fast as the large turbine market, but the wind is turning.
"The demand for small wind power stations has witnessed a strong increase, as locally produced wind power is an interesting and financially sound alternative for use in detached houses and leisure homes as well as in industry, and agriculture," she says.
For example, a Finnish energy company St1 intends to utilize Eagle’s small wind power stations to provide the electricity for its service stations.
"We are also participating in global projects in several developing countries," Siitonen concludes.
Source: Energy and Enviro Finland (www.energy-enviro.fi); 27 February 2009
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