May 11, 2009 Clean, renewable energy is freely available – in the form of wind, sun and water. However, harnessing it reliably and cost-effectively remains a barrierWind power is one of the fastest growing alternative energy markets and researchers at Purdue University
and Sandia National Laboratories in West Lafayette, Indiana, are
working to make wind turbines more efficient, reliable and resilient.
They are using sensors and computational
software that constantly monitor forces exerted on wind turbine blades
with the aim of developing a smarter wind turbine structure.
Improving reliability and resilience
“Our aim is to do two things: improve
reliability and prevent failure. The most direct way to enable those
two capabilities is by monitoring forces exerted on the blades by
winds,” says Douglas Adams, a professor of mechanical engineering and
director of Purdue’s Center for Systems Integrity.
According to doctoral student Jonathan White,
who is working on the project with Adams, “the ultimate goal is to feed
information from sensors into an active control system that precisely
adjusts components to optimize efficiency.”
One of the main problems with wind turbines is
that the wind can suddenly change direction and force, decreasing
efficiency and causing costly damage to blades. The team from Purdue
and Sandia believes its technique can help prevent this by providing
real-time information to the turbine’s control system and predicting
Sensors were embedded in the turbine blade as
it was being built. Testing on a research wind turbine in Texas has
shown that using a trio of sensors and “estimator model” software
accurately reveal how much force is being exerted on the blades.
In the future, turbine blades could be fitted
with flaps like those on an airplane’s wings. Sensors inside the blades
would enable blade pitch to be adjusted in real time to respond to
“Wind energy is playing an increasing role in
providing electrical power,” says Adams. “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?”
Alternative energy is big business
put the value of the renewables market at USD$246 million in 2007, and
there’s no shortage of companies trying to improve on existing
technologies and share the profits. Catch the Wind is a Virginia-based
company that has developed a fibre optic laser sensor, the Vindicator.
It sits atop turbines and measures wind data in real time, allowing
adjustments to be made to the turbine well before the wind comes. The
company’s research suggests it can provide an increase of up to a 10
percent in turbine output power.
claims to increase power output by between 15 percent and 30 percent,
when the turbine is spinning. It uses aerodynamic modeling to direct
the surrounding wind flow to the critical area of the blades, via a
passive structure located near each of the turbines.
believes its generator reduces costs and increases output by up to 50
percent because more than 90 percent of its energy can be converted
into electricity. Rather than use a traditional mechanical generator to
compensate for variations in the wind, they have developed a
self-adapting electrical system that can scale up and down with
available energy in a way that would take almost 70 traditional
generators to match.
This isn’t the only example that demonstrates biomimicry can provide answers. We recently covered the Tubercle Technology,
a breakthrough in aerodynamic design offering more power, less noise
and the ability to generate power at wind speeds that are much too slow
for traditionally shaped turbines.