A forthcoming high-performance fabric by Owens Corning purports to remove nearly a metric ton of fabric and resin from 2.0 megawatt (MW) wind turbines.
The product, called Ultrablade, will be commercially available in January 2011. The company says Ultrablade fabrics in epoxy resin support the continuing market shift to longer, lighter, stiffer wind turbine blades.
"Ultrablade fabric solutions give designers much more freedom in developing longer blades for today's large turbines," said Dr. Chris Skinner, director of global technical marketing for OCV Technical Fabrics, one of three main units in Owens Corning’s Composite Solutions Business.
Reducing Weight, Thickness
Compared to standard fabrics, the manufacturer says, Ultrablade fabrics in epoxy resin can:
• Reduce spar weight by up to 18% while keeping length constant;
• Increase blade length by up to 6%;
• Improve blade stiffness by up to 20%;
• Decrease blade thickness by up to 6%; and
• Reduce total blade weight by up to 5%.
"As the market continues to move to larger-capacity wind turbines needing longer blades, designers can use a combination of several improved properties in different areas of a blade," said Skinner. "They can choose to increase blade length for any given weight while keeping the thrust constant and assuring sufficient tower clearance.
“At lower wind speeds, weight-saving Ultrablade fabric solutions can help increase a blade's aerodynamic lift, torque and energy output,” Skinner said. “The end result will be higher annual energy production from optimized blade designs using high-performance fabrics."
World Market Trends
New generation wind turbine designs are continuing to increase the turbines’ power generating capacity. Longer blades have become a common feature of larger-capacity designs. Covering a larger area effectively increases the tip-speed of a turbine at a given wind velocity, thus increasing the system’s energy extraction capability, according to Owens Corning.
According to a report published by China Daily in February, market demand has shifted in recent years to 40.3-meter (132-foot) blades, from 37.5-meter (123-foot) blades.
Wind power in China accounted for 25.1 gigawatts (GW) of electrical generating capacity at the end of 2009, and the country has identified wind power as a key growth component of its economy. China is now the world’s largest producer of wind turbines and second-largest producer of wind power, after the United States.
According to the Global Wind Energy Council, the industry’s worldwide association, China is expected to remain one of the main drivers of global growth in the coming years, with annual additions of more than 20 GW by 2014. This push will be supported by very aggressive government policies and the growth of the domestic industry, the association says. The Chinese government has an unofficial target of 150 GW of wind capacity by 2020.
Global Power Demand
GWEC recently released a report saying that wind could meet 12% of global power demand by 2020, and up to 22% by 2030. Currently, a new wind turbine is erected every 30 minutes, with one in three turbines located in China, said the study, co-authored by Greenpeace International.
The 1,000 GW of wind power capacity projected to be installed by 2020 would save as much as 1.5 billion tons of CO2 every year, according to Global Wind Energy Outlook 2010.
“These reductions would represent 50-75% of the cumulative emissions reductions that industrialized countries committed to in their 2020 ‘Copenhagen pledges,’” the report said. “By 2030, a total of 34 billion tons of CO2; would be saved by 2,300 GW of wind power capacity.”
Ultrablade will be produced in a number of facilities globally. In China, the products will be manufactured at plants in Changzhou and Doudian.