Bob Dylan was wrong: You do need a weatherman to know which way the wind blows.
At least, you do if you are Xcel Energy. With a growing portfoilo of wind energy — now 14 percent of all its Colorado power and 12 percent companywide — the utility is seeking a better forecast of how much power its turbines will produce on any given day.
That knowledge could help the utility — the nation’s largest wind power generator — save its customers $10 million to $12 million over the next two years, said company spokesman Tom Henley.
Boulder’s National Center for Atmospheric Research and the Golden-based National Renewable Energy Laboratory are collaborating on a forecasting model that will be able to figure out the likely wind pattern at Xcel’s 47 wind farms in Colorado, New Mexico, Minnesota, Texas and Wyoming.
The forecast model would estimate wind-farm power outputs every 15 minutes for the next day and hour-by-hour projections for a three-day period, said William Mahoney, who is overseeing the project for NCAR.
Forecasting wind is a complex exercise because it encompasses many elements: global conditions; regional topography, like the Rocky Mountains; and data such as the number of trees and the thickness of grass.
“Subtle changes can make a very big difference,” Mahoney said. “The wind can be blowing at 50 miles an hour on a mountaintop and it is calm in Denver.” But a forecast can still be developed by combining a wide variety of data points with even better data from Xcel’s wind farm, where turbines will be wired with sensors.
Xcel’s Henley said that the forecasting should enable the company to plan better and avoid buying power in the expensive spot energy market.
The utility is financing the 30-month project for an undisclosed sum, but Henley said Xcel expects to make its money back in the first year.
Mark Jaffe: 303-954-1912 or mjaffe@denverpost.com
