Laser Sensors for Wind Turbines

A system that detects gusts before they arrive reduces wear, boosts output.

A new fiber-optic laser system can measure wind speed and direction up to 1000 meters in front of a wind turbine, giving the massive machines enough precious seconds to proactively adapt to gusts and sudden changes in wind direction. The device, developed by Catch the Wind, a startup based in Manassas, VA, could improve the efficiency of wind turbines and keep them from breaking down.

Wind spotting: A prototype of a new laser-based LIDAR system, shown here, can horizontally project three invisible laser beams up to 300 meters in front of a wind turbine. Small particles in the wind are detected as they cross the beams. Credit: Catch the Wind

The device could help lower the cost of renewable electricity from wind. Wind turbines lose roughly 1 percent of their operating efficiency for every degree their blades are out of alignment with the oncoming wind. Catch the Wind claims that its laser system can boost turbine power output by 10 percent by improving orientation accuracy. The pitch of the blades can also be adjusted in advance of the wind to reduce wear and tear on turbine gearbox components and blades, lowering repair and maintenance costs by up to 10 percent and extending the operating life of a wind farm, the company says.

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John Kourtoff, chief executive officer of offshore wind developer Trillium Power, calls Catch the Wind's approach "conceptually intriguing" if it can both reduce wind-farm costs and increase revenues. "On the face of it, it makes sense. It would be advantageous for us," he says. "But I'd have to see real field data."

Current wind-energy measurement systems--both mechanical anemometers and more advanced LIDAR (light detecting and ranging) devices--are used primarily to determine if a location is suitable for a wind farm. The systems are also kept as part of on-site weather stations used for longer-term wind forecasting. Real-time data can also be gathered by mounting a small anemometer on the back of a turbine's nacelle, Kourtoff says. The problem with this setup is that the air is so disturbed after passing by the turbine blades that measurements are often skewed and unreliable. Also, the turbine can only respond to wind changes after its blades have been hit, leaving them vulnerable for a few seconds to a range of punishing forces caused by wind shear, gusts, and turbulence.