Wind Manufacturing and Supply Chain

The United States Department of Energy (DOE) works with suppliers to promote advanced manufacturing. Its goals are to increase reliability while lowering production costs, and to promote an industry that can meet all demands domestically while competing in the global market. It does this through industry partnerships and targeted R&D investments to integrate new designs, materials, and processes into manufacturing facilities, thus making wind turbines a more affordable source of renewable energy for communities around the country.

Manufacturing is the First Step in Affordable Wind

The U.S. wind market has grown substantially over the years into an increasingly complex supply chain. Numerous facilities specializing in blades, towers, generators, and turbine assembly exist across the country.

Illustration of the United States, showing the new wind facilities that opened or were announced in 2012, listing them by turbines, blades, towers, nacelle components, and 'others.'

Source: 2012 Wind Technologies Market Report.

Advancements in composite materials, automation, and more efficient manufacturing processes have helped domestic manufacturers to dramatically increase productivity throughout the past decade. The wind supply chain that has developed in the United States in recent years has nearly tripled the domestic content of wind turbines installed in the United States.

Two blue and green pie charts labelled 'Imported versus Domestic Content for U.S. Wind Projects*. The chart indicates that from 2006-2007 only 25 percent of content was domestic and 75 percent was foreign. But that in 2012 70 percent of the content was domestic and 30 percent was foreign. *Based on total equipment-related wind turbine costs for available trade categories from USITC.

Source: 2012 Wind Technologies Market Report.

As the manufacturing process progresses and grows, so too do the size, complexity, and transportation costs of wind turbines, increasing the necessity for local manufacturers who can overcome logistical barriers. Currently, the average utility-scale wind turbine contains roughly 8,000 parts and encompasses blades that can reach up to75 meters (roughly 250 feet) in length. With the goal of one day furnishing turbines with blades greater than 100 meter on towers surpassing 140 meters, advanced manufacturing techniques will be necessary to meet the demands for wind energy.

Breaking Down the Manufacturing Process

Blades

Due to the size and complexity of turbine blades, each blade must be crafted by hand in order to ensure the highest quality and reliability. The Advanced Manufacturing Initiative for blades—a partnership between DOE, Sandia National Laboratories, TPI Composites, and Iowa State University—helped establish advanced techniques which reduce the time it takes to produce a single turbine blade by approximately 37% (from 38 to 24 hours). Subjected to the elements without rest, turbine blades must be able to maintain their strength and aerodynamic structure without succumbing to the pressure of non-stop operation.

Advanced Drivetrains

The combination of components that come together so that the rotating blades of a wind turbine can produce electricity, typically including the gearbox and the generator, are referred to as the drivetrain. Advanced manufacturing techniques developed in conjunction with the DOE Wind Program's Next Generation Drivetrain projects are expected to produce more efficient, reliable, and affordable drivetrains for future wind turbines. These advancements include new single-stage gearboxes, permanent magnet generators, high efficiency power electronics, and superconducting generators. New and innovative approaches to drivetrain manufacturing will continue to be necessary as turbines continue to increase in size and energy output.

Infrastructure and Logistics

As the demand for renewable energy is increasing, American manufacturers are finding ways to overcome infrastructure and logistics constraints necessary to continue lowering the costs of wind energy. These constraints include highway underpass heights limiting the size of wind towers, finding cranes able to lift and install nacelles, and the trucking fleet's difficulty in transporting longer wind blades. In a new study released by the National Renewable Energy Laboratory, Analysis of Transportation and Logistics Challenges Affecting the Deployment of Large Wind Turbines, it was concluded that the technologies that enable larger wind turbines have led to reductions in the cost of wind energy. However, transportation and logistics challenges are limiting the size and height of towers that can be deployed throughout the country. Addressing these challenges head-on, in January, 2014 DOE announced a $2 million funding opportunity for projects to design taller towers while implementing innovative techniques and designs that avoid common logistical roadblocks.

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