WindTracer Uses Lasers to Predict Wind Direction
WindTracer systems have been used worldwide for over a decade to detect hazardous winds and aircraft wakes.
CREDIT: Lockheed Martin
One of the biggest problems with wind energy is that it's difficult to predict the behavior of the wind itself and, by extension, to plan for the amount of power wind turbines are able to generate in a given day.
But predicting the wind and, in turn, the amount of wind power that will be generated and eventually sold, is becoming easier and more reliable, thanks to devices like WindTracer, a scanner that uses a laser to “trace” microscopic dust particles in the wind.
WindTracer works by firing an infrared laser into the atmosphere at a rate of 750 times per second. The light travels between 15 and 30 kilometers, or until it comes into contact with an object, such as dust or other airborne particles, in which case it reflects off the object and bounces back toward the WindTracer. [See also: Jets and Drones Powered by a Mighty Wind]
The WindTracer uses the reflected signal to calculate the speed of the dust particles blowing in the wind.
This method is called lidar — the word comes from "light detection and ranging," the same way the word "radar" comes from "radio detection and ranging." The infrared light of the laser is strong enough to return a reading but still weak enough that it won't harm or burn any other objects it hits, or disrupt other equipment, such as airplane sensors.
Using this method, WindTracers can gather reliable data on the wind's direction and strength between two and six hours before it reaches the device.
The WindTracer was originally developed by Coherent Technologies to measure wind strength and direction at airports. In 2005, the company was purchased by defense contractor Lockheed Martin, which has since expanded WindTracer's applications.
The Pentagon, for example, uses two WindTracer devices to monitor wind direction and speed over Washington, D.C., so that if the city is ever attacked, the military will have immediate data on which direction the radiation or chemical fallout will blow.
The company is currently looking to expand WindTracer's usage for renewable energy. For instance, WindTracers are being used to identify ideal sites for future wind farms.
In addition, several wind farms in the United States now use the WindTracer to predict their energy output and make market forecasts, which makes it easier for wind farm developers to sell the output of the wind farms to power companies, explained Mike Margulis, director of WindTracer programs at Lockheed Martin.
In fact, the WindTracer is just one of several lidar-based devices currently on the commercial market. BlueScout Technologies, for example, developed a device called the Vindicator laser wind sensor, which has a shorter range than the WindTracer’s but is specifically designed to help wind turbines determine the best way to point and angle their blades for optimum energy output. [See also: U.S. Could Use 80 Percent Green Energy by 2050]