According to a study led by researchers at Sandia National Laboratory, a new carbon fiber material could bring cost and performance advantages to the wind energy industry if developed commercially.

The blades made of carbon fiber are 25 percent lighter than those made of traditional glass fiber. This means that carbon-fiber blades may be longer than glass-fiber blades, so they can capture more energy at lower wind speeds. Brandon Enix, Spain, a wind energy researcher at Sandia Laboratories and lead researcher on the project, said that because of the high fatigue resistance of carbon fibre, therefore, the use of carbon fiber can also extend the life of the blade.

The project is funded by the Office of energy efficiency and renewable energy and the wind energy technology office of the Department of Energy. Partners in the project include Oak Ridge National Laboratory and Montana State University in Bozeman.

Of all the companies that make wind turbines, only one uses carbon fibre extensively in its blade design. Wind turbine blades are the world's largest single-piece composite structure, and if a material that competes with fiberglass-reinforced composites can be obtained commercially, the wind industry is likely to be the biggest market for carbon fibre. Enix, Spain.

Cost is a major consideration in parts design for the wind energy industry, but turbine makers must also produce blades that can withstand compression and fatigue loads, rotating for up to 30 years.

Enix, Spain and his colleagues wanted to see if the new, low-cost carbon fibers developed by the Oak Ridge National Laboratory could meet performance requirements and be cost-effective for the wind energy industry. The material began as a precursor widely used in the textile industry, containing large bundles of acrylic fibers. The manufacturing process that heats the fibers to turn them into carbon is followed by the intermediate step of pulling the fibers into the wood. The carbon fiber produced by sheet manufacturing pultrusion process has high performance and reliability for blade manufacturing, and increases the production capacity.

When the team studied low-cost carbon fibers, they found that they outperformed current commercial materials in specific cost characteristics of greatest interest to the wind energy industry.

ORNL provided carbon fiber development samples from its carbon fiber technology facility to compare with composites made from this material and similar composites made from commercially available carbon fibers.

Bozman's colleagues at the Montana State University-bozeman measured the mechanical properties of the new carbon fibers, compared with commercially available carbon fibers and standard fiberglass composites. Ennis then combines these measurements with ORNL's cost modeling results. He used this data in his blade design analysis to assess the impact on the system of using new carbon fibers rather than standard carbon or glass fibers as the main structural support for the blades. The study was funded by the U. S. Department of Energy's Office of wind energy technology.

Enix, Spain and his colleagues found that the new carbon fibre material had a compressive strength of 56 per cent per dollar more than commercially available carbon fibre, the industry benchmark. In general, manufacturers increase costs by using more materials to adjust parts to lower compressive strength. Considering the higher unit cost of the new carbon fiber, Ennis calculated that the material cost of the new carbon fiber wing cap would be reduced by about 40 percent compared to the new carbon fiber. The carbon fiber wing-beam cap is the main structural component of the wind turbine blade. Carbon fibre for commercial use.