By Ben Gruber
The measurements taken inside a Vanderbilt University wind tunnel could hold the key to making wind power a viable, cost effective energy source in the future, according to Professor Doug Adams and his team of engineers.
Inside a massive 20,000 square foot (1860 square meter) laboratory, Adams and his team fitted inertial sensors on two turbines as a 30mph (48km) wind blasts inside a tunnel. His goal is to "listen in as the turbines talk to each other".
"They are like the sensors in your steering wheel but they are just a lot more sensitive than that. We use that sensor to track the motion, to do motion tracking of the blade but monitor also what we call the dynamic response," said Adams, a professor of Civil and Environmental Engineering.
"Every time a blade moves we are monitoring it and that tells us something about that conversation that is happening from one turbine to the next," he added.
That conversation could offer clues on how the wake effect of one turbine influences the performance of another. The changes in a single turbine's efficiency due to wake effect is incredibly small, but in a wind farm that has 100 turbines, those tiny changes could add up significantly, Adams explains.
"We think we can lower the cost of maintenance by two to three cents per kilowatt hour. That is a game changer from standpoint of the viability of wind energy. It becomes absolutely competitive with the fossil fuels that we rely on today, without subsidies it starts to become cost competitive," he said.
Using computer algorithms, Adams and his team process the data and use it to generate models and adjust the rotors of a turbine to compensate for the wake effect and increase its efficiency. Even more promising, he says, is that these tiny real-time adjustments can significantly decrease the fatigue load on a turbine and extends its lifespan.
"So if we eliminate or reduce those fatigue loads we can make them last for much longer. So instead of 15 years it is lasting 25 years," Adams said.
According to the data, the sensors could significantly increase the productivity of established wind farms while helping design future farms that produce more electricity with fewer turbines, another piece of the puzzle that will ultimately drive down the cost of wind energy while utilizing less land for its production.