Researchers from the Center for Sustainable Energy at Notre Dame (ND) in the US have designed a new wind turbine tower which could reduce costs and improve efficiencies.
The new ultra-tall wind turbine tower that can be extended to a height of up to 140m has been developed with support from Notre Dame Research center ND Energy.
When computationally tested, the turbine validated its optimized shape, which is designed to reduce wind impact on the tower while improving the dynamic stability of the structure.
ND Energy postdoctoral fellow Yanlin Guo said: "The taller the wind turbine tower, the stronger and more consistent the wind being captured is due to reduced ground friction.
"Additionally, a taller tower allows the necessary ground clearance for installing larger rotors, which can produce more energy, leading to a reduction in energy costs overall."
The Notre Dame researchers said that they selected pre-stressed concrete that has had initial compression introduced by steel cables to overcome tension weaknesses of concerts in order to create more efficient structural system.
Using a post-tensioning technique, the steel cables can be bent to meet shape requirement and can be stretched to keep the tower components together, they said.
Civil & Environmental Engineering & Earth Sciences (CEEES) Robert Moran professor Ahsan Kareem said: "You can think about the tower structure like a piece of bread: when you pick up bread, it tends to sag.
"But if you pick it up with one finger on each end and push it together, it creates resistance to tension so it is held together. By using pre-stressed concrete, we create a similar tension resistance so as the wind blows against the tower, it will more easily maintain its shape."
The project combines a pre-stressed concrete structural concept and optimized tower shape to increase resistance while reducing wind loads.
CEEES professor and associate chair Yahya Kurama said: "Each of these objectives are important to consider when attempting to design an efficient wind turbine tower that is intended to be nearly twice as tall as the industry standard."