Drawing on sensors and computers, US scientists have come with a hot new method of assessing the forces placed on the blades that form part of wind turbines.  Their work marks progress towards an aim of developing turbines that are sensitive to alterations in wind speed and direction and which, thus, are more energy efficient than the current generation.

Wind Turbine Research

The scientists’ wind turbine research is taking place in Texas and involves representatives from both Sandia National Laboratories and Purdue University, spearheaded by Purdue’s Professor Douglas Adams and Jonathan White.

“The ultimate goal is to feed information from sensors into an active control system that precisely adjusts components to optimize efficiency”, said White.

“Wind energy is playing an increasing role in providing electrical power”, Adams added. “The United States is now the largest harvester of wind energy in the world. The question is, what can be done to wind turbines to make them more efficient, more cost effective and more reliable?”

The scientists placed uniaxial and triaxial accelerometers – types of sensors – into a wind turbine blade at its construction stage.  These sensors in place, the blade is now being put through tests at the Texas-based Agriculture Research Service laboratory run by the US Department of Agriculture.

Wind Turbine Technology

Similar sensors could, in years to come, be incorporated into wind turbine technology where the blades feature moveable control surfaces - much like those found on an aircraft – through which their movement can be vectored in response to local climate variations.  The sensors’ role would involve transmitting climate data in real time, allowing modifications to the turbines to be made without delay.

“The aim is to operate the generator and the turbine in the most efficient way, but this is difficult because wind speeds fluctuate”, Adams explained. “You want to be able to control the generator or the pitch of the blades to optimize energy capture by reducing forces on the components in the wind turbine during excessively high winds and increase the loads during low winds. In addition to improving efficiency, this should help improve reliability. The wind turbine towers can be 200 feet tall or more, so it is very expensive to service and repair damaged components.”

The sensors are able to calculate two forms of wind speed acceleration, known as dynamic acceleration and static acceleration.  The first refers to general wind gust, while the second looks at steady wind speeds in relation to gravity.  In order to be able to establish force (on the wind turbines), it is necessary to look at both.