Cost Effective Approach to Tall Composite Wind Turbine Towers by Allowing On-Site Fabrication

70462S02-II Nearly half of the expected 50% improvement in wind turbine production will come from towers that will be twice the height of those common in the late 1980s. Although much technology input has gone into blades, the technology for towers has been at a virtual standstill. This is especially true for large Megawatt-size turbines, because the cost of the steel and concrete towers constitutes 30% of their cost. This project will develop technology for manufacturing composite towers on-site, providing major savings in transport and labor. A telescoping composite tower design will be used to help with the lifting tasks for the nacelle and blades. Phase I demonstrated the feasibility of a new family of towers that can be completely manufactured in the field. The feasibility of tower erection without the need for a tall crane also was established. Lastly, the tower was designed to allow easier mounting of the nacelle and easier installation of the blades. Phase II will create and certify a 26-meter-tall proof-of-concept composite tower for mating with the nacelle. The tower will be instrumented, and dynamic tower response data will be captured during a three month time frame. Commercial Applications and Other Benefits as described by awardee: The composite tower should have broad application in both the replacement market for steel towers and in new installations. The same technology, currently being applied to composite highway sign bridges, also should be of interest to the electrical utility market for tall poles.