Eric Bland, Discovery News

 

May 26, 2009 -- Today's wind turbines are like race cars with one gear. Slow off the line and crippled at high speeds, the turbines are effective at generating electricity only within a sweet spot of moderate wind speeds.

Scientists from Purdue University want to change this by creating intelligent wind turbines that shape-shift with the wind. These smart wind turbines would help maximize the amount of electricity generated by wind power while ensuring longer life spans for wind turbines.

"We eventually want to put aerolons or actuators on the blades to quickly adapt how the blade flies through the air," said Jon White of Purdue University, an engineer working on the project.

"One second you will have one kind of blade, and then the next second it will change into another shape, depending on the wind speed," said White.

White and his colleagues recently installed accelerometers along three 30- foot-long blades of a research turbine near Amarillo, Tx.

Made of balsa wood and fiber glass, the blades are right on the border between personal and commercial-sized wind turbines, said White.

The accelerometers measure how the blades subtly twist and turn as they cut through the air. In the first stage of their research, the Purdue scientists are measuring for blade fatigue and efficiency in an effort to design future turbine blades that last beyond the usual 20 years.

Once they have gathered enough data, the team plans to link the data from the accelerometers to mechanical actuators or aerelons, the flat panels on airplanes that help direct airflow, on the ends of the blades and to a control panel.

Traditionally, wind turbine blades are fixed. They have one fixed shape optimized to perform during moderate wind speeds. During low wind speeds the blade is too narrow for the wind to push the blade around efficiently. High wind speeds, which could generate the most power, push the blades too quickly, threatening to break the blade and can force operators to limit the speed and energy production.

Linking the accelerometers to the actuators would enable the turbine blade to quickly change shape and adapt to whatever kind of wind conditions are present to optimize the amount of electricity they can produce and extend their life span as long as possible.

Wind turbines are already pretty efficient, says Jose Zayas of Sandia National Laboratories' Wind Energy Technology Department. Intelligent wind turbines could help generate single digit increases in electricity generation. Add to that the lower installation costs and a longer life span, however, and the savings will start to add up nicely.

"All of this will help reduce the cost of wind energy," said Zayas. Even if accelerometer-equipped blades don't physically change their shape, the increased data coming into turbine operators will help them to delicately fine tune their systems.

Smarter wind turbines could be available in as little at three years, although it will take longer for shape-shifting turbines blades to appear.