The U.S. Department of Energy (DOE) has announced it is awarding $2 million to support two projects focused on manufacturing taller wind turbine towers. Although wind turbines installed in 2013 had an average height of 260 feet, the DOE says the projects will support new techniques to produce towers nearly 400 feet tall.
As the DOE explains, winds near the ground are often slower and more turbulent, reducing the amount of electricity installed turbines can generate. Taller wind turbines capture the stronger, more consistent winds available at elevated heights, increasing the number of potential locations where wind farms can supply cost-effective power.
The DOE says Boston-based Keystone Towers will implement an on-site spiral welding system that will enable turbine towers to be produced directly at or near the installation site, freeing projects of transportation constraints that often limit turbine height. Adapted from an in-field welding process used by the pipe manufacturing industry, Keystone's spiral welding technique can be scaled up to produce large-diameter steel towers that the company says will be 40% lighter than standard turbine towers, which could lower the cost of energy by 10%.
Iowa State University will develop a hexagonal-shaped tower that combines high-strength concrete with pre-stressed steel reinforcements to assemble individual tower modules and wall segments that can be easily transported and joined together on-site. The DOE says that due to the modular design, thicker towers capable of supporting turbines at increased heights can be produced at a reduced cost.
According to the DOE, improving the manufacturing process for taller wind turbine towers supports the department's broader Clean Energy Manufacturing Initiative, which aims to increase U.S. competitiveness in the production of clean energy products and boost domestic manufacturing competitiveness across the board by increasing energy productivity.