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

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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

fatigue.

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

changing conditions.

“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

The Renewable Energy: Global Industry Guide

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.

The Leviathan Wind Energizer

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.

ExRo Technologies

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.

Announcement from our Chairman, David C BarclayThe World Renewable Energy Association are delighted to announce the launch of a brand-new initiative exclusively for its members. The Renewable Energy Finance Hub has been launched following the largest survey undertaken with UK businesses conducted by WoREA in conjunction with the UK Government and its partners. Reduce your businesses carbon footprint today and begin your journey towards net zero!