Image may be NSFW.
Clik here to view.
When the wind hits the fan, things may not be pretty in the back. The choppy wake produced behind a wind turbine can make it tough for the other turbines on a wind farm to work at peak efficiency.
Engineers from GE’s renewable energy business and Global Research Center have been looking for ways to smooth out the wind flow behind the turbines. Researchers collected and analyzed terabytes of wind farm data. They saw that when turbines let some of the wind energy pass by pitching and slowing their blades, the wake was less turbulent. Product Line Leader Charu Mehendale explains how these findings can be used to increase wind farm energy output.
“Right now, individual turbines are set up to get what they can from the wind,” he said. “But when we make them less selfish and pass some of the good wind on, the whole wind turbine power plant works better.”
Acting on their findings, the GE team developed a big data system, called Wind Plant Wake Management, that analyzes wind conditions and output and optimize the farm’s performance as a unit.
Meanwhile, other independent researchers are working to put more real-world data into the mix. In the Midwest, engineers have been using the region’s bone-chilling winters to their advantage. Looking to add information from operating turbines to the computer models and small wind tunnels traditionally used to study how wind turbines interact with the air around them, they turned to the weatherman.
Image may be NSFW.
Clik here to view.
Snowflakes behind a wind turbine show the swirling vortices in the wake of the spinning blades.
The team from the University of Minnesota and University of Illinois at Urbana-Champaign set up a powerful light behind a full-sized 2.5 megawatt, 260-foot-tall wind turbine and waited for snow. When a heavy storm eventually started blanketing the area, they recorded how the turbine’s spinning blades left turbulent airflow and swirling vortices behind it.
The snowflakes acted as flow tracers in the turbulent wind and provided the researchers with a new method to understand what happens when the machines operate. The results could be used to fine-tune machine-level and wind farm construction to make both more efficient at harvesting energy from the air.
"To improve power production and structural reliability of wind turbines, there is a pressing need to understand how turbines interact with the atmospheric boundary layer," the researchers wrote in their recently published paper in the journal Nature Communications.
The resolution of the data they got from watching the movement of snowflakes, they say, is high enough to monitor the specifics of changing turbulence and vortices, and to tie that back to how the machine is operating. “Our experiment provides an unprecedented in situ characterization of flow structures around utility-scale turbines,” they write.
GE’s Mehendale, meanwhile, estimates that his company’s technology could improve the efficiency of a wind farm by up to 2 percent, and boost its profits by up to 8 percent a year.
