Research shows that carbon fiber turbine blades can improve the efficiency of wind power generation
A study led by researchers at Sandia National Laboratory shows that a new carbon fiber material, if developed commercially, will bring cost and performance benefits to the wind power industry.
The blades made of carbon fiber are 25% lighter than those made of traditional glass fiber. This means that carbon fiber blades may be longer than glass fiber blades, so more energy can be captured in lower wind areas. Sandia laboratory wind energy researcher, the project's lead researcher, said that switching to carbon fiber can also extend blade life, because carbon fiber materials have high fatigue resistance. The project is funded by the wind energy technology office of the energy efficiency and Renewable Energy Office of the Ministry of energy. Partners of the project include Oak Ridge National Laboratory and Montana State University.
Of all the companies that make wind turbines, only one widely uses carbon fiber in blade design. Wind turbine blades are the world's largest single piece composite structure, and if a material that competes with glass fiber reinforced composites on a cost value basis can be bought on the market, the wind industry can represent the largest market for carbon fiber materials, the researchers said.
However, wind and carbon fiber industries do not overlap at present. Carbon fiber manufacturers face barriers to innovation as the wind industry only uses commercial materials to design wind turbine blades, as the introduction of new production lines in the wind industry creates high capital costs.
New low cost carbon fiber has good wind power performance
Cost is a major consideration in the design of components in the wind power industry. However, turbine manufacturers also have to produce blades that can withstand the compression and fatigue loads of the blades when they rotate for up to 30 years.
Researchers want to know whether a new low-cost carbon fiber developed by Oak Ridge National Laboratory can meet the performance requirements and also bring cost-effectiveness to the wind power industry. This material begins with the precursor widely used in the textile industry, which contains thick acrylic fiber bundles. During the manufacturing process, the fiber is heated to convert it into carbon, and then an intermediate step is taken to pull the carbon fiber into wood. The carbon fiber produced by pultrusion process has the high performance and reliability required for blade manufacturing, and also has high production capacity.
When the team studied this low-cost carbon fiber, they found that it performed better than current commercial materials in terms of the most interesting cost characteristics of the wind energy industry.
ORNL provided samples of carbon fiber development for its carbon fiber technology facility, as well as composites made from this material and similar composites made from commercial carbon fiber for comparison. Colleagues at Montana State University measured the mechanical properties of new carbon fiber composites with commercially available carbon fiber and standard glass fiber. The researchers then combined these measurements with ORNL's cost modeling results. He used these data in the blade design analysis to assess the system impact of using new carbon fiber (rather than standard carbon fiber or glass fiber) as the main structural support for wind blades.
Increasing compressive strength can save cost
The researchers found that the compressive strength per dollar of the new carbon fiber material is 56% higher than that of commercial carbon fiber, which is the industry benchmark. Generally, manufacturers use more materials to make components to adapt to lower compressive strength, which will increase costs. Considering the higher unit cost compressive strength of the new carbon fiber, Ennis's calculation predicts that the material cost of the spar cap (the main structural component of the wind turbine blade) made of the new carbon fiber can be reduced by about 40% compared with the commercial carbon fiber.
Compared with glass fiber, the new carbon fiber even reduces the expected material cost of onshore turbine design due to its improved fatigue resistance. Other results of using the new carbon fiber in blade design, such as weight reduction and longer fatigue life, could affect the overall turbine design, resulting in additional cost and performance benefits, the researchers said.
"Although the best carbon fiber for the wind power industry does not yet exist on the market, the performance characteristics of this new type of textile carbon fiber have higher value for the specific load that the wind turbine bears," the researchers said The commercialization of this material can make the benefits of carbon fiber materials more widely realized by the wind energy industry and reduce the overall cost of wind energy. "
Original title: carbon fiber turbine blades can improve the efficiency of wind power generation