Wind can be a tricky thing – especially when you are depending upon it to generate electricity. It can blow too hard or not at all. And yet when the wall switch is flicked we expect the lights to turn on.
It also became clear the poor understanding of wind shear and turbulence was wreaking havoc – reducing energy output by as much as 20 percent and wearing out turbines that were supposed to have a 20-year life in just five years.
When there is no wind a utility has to suddenly ramp-up either coal-fired or gas-fired units, a potentially expensive exercise, and when there is too much wind a turbines may have to be taken off line.
The problem led to a partnership in 2009 between the National Center for Atmospheric Research in Boulder and Xcel Energy to see if with better data wind farms could be more effectively managed.
To create a more sophisticated forecast NCAR combined data from satellites, aircraft, radar, ground-based weather stations, and sensors on turbines and created a custom computer model to view the shifting winds and a real-time system that continuously updates the simulations from the model.
All this is fed into a forecasting tool and a wind energy conversion system – giving utility operators a finely tuned and real-time vision of the resource.
“Wind is particularly elusive to predict, because small changes in atmospheric temperature or pressure can completely alter wind speed and direction,” says Sue Ellen Haupt, an NCAR program director who oversees the project. “We’re very pleased that this combination of cutting-edge computer models and real-time observations is helping produce more reliable wind energy for millions of Xcel Energy customers.”
The bottom line: In 2010 the NCAR tool saved Xcel $6 million.
There will be more on the project in The Denver Post on-line and in print tomorrow.