Along a ridge south of Touchet near the Stateline Wind Project turbines, there's not a sound to be heard but a persistent beeping.
Every few seconds what sounds like the rising notes of a scale ending with the high-pitched tweet of a small bird is repeated.
The sound rises 1,600 feet into the air as part of a Pacific Northwest National Laboratory project to see if predictions of wind might be improved.
"We know that the wind will blow, but the real challenge is to know when and how much," said Larry Berg, a PNNL atmospheric scientist.
Sign Up and Save
Get six months of free digital access to the Tri-City Herald
That information would be useful for managing electrical grids which integrate wind power.
"One of the big challenges of wind power is it is intermittent," said Rob Newsom, a PNNL scientist. "We're at the mercy of Mother Nature. Wind doesn't always blow when we want it."
That can make adding wind power to the grid problematic, because the grid requires a steady power load.
In hopes of improving wind predictions, researchers are using sophisticated meteorological tools to gather data about the wind at the height of wind turbines -- about 350 feet -- and above. Now most available wind measurements are made about 30 feet off the ground.
They are using Doppler sodar, which emits sound at a known frequency. The sound bounces off small differences in temperature and humidity. When it returns to the ground -- much like an echo -- it has a changed frequency that can be related to how strong the wind is blowing.
The wind direction and speed are determined at regular intervals from 100 to 1,600 feet high, with a goal of determining wind speeds at the height of a wind turbine. The arms of a turbine rotate from a hub about 350 feet high.
A second piece of equipment that sends three microwave beams higher into the sky also is being used to provide additional data about wind higher in the sky. Its waves are bounced back when they hit variations in moisture and temperature.
Additional data is collected closer to the ground by anemometers mounted on a commercial communications tower already at the site that measure wind speed and direction.
Together the three tools are expected to give a more comprehensive understanding of how wind behaves, particularly at the height of a wind turbine.
That information can be used to predict wind. In addition it can be used to assess the accuracy of the way data is more traditionally gathered and used to predict wind using computer models.
Data will be compared with the National Weather Services' NEXRAD Doppler radar weather station 19 miles south of the research project in Pendleton. It's part of a national network of stations routinely used by television meteorologists to show clouds and precipitation in colorful digital maps.
But it also provides a one-dimensional look at how the wind varies around the radar. That data can be plugged into an algorithm that makes a number of assumptions that don't always hold true to predict wind behavior.
But the hope is the data comparison will show that the NEXRAD Doppler radar data produces a reasonably accurate snapshot of wind speed and direction.
When grid operators know wind power is coming, they might prepare for the influx of power by reducing other power sources. In the Northwest that can mean spilling river water over hydroelectric dams instead of sending the water through the dams' power-production turbines.
But in some instances gusts can come up quickly or stop unexpectedly.
"We worried about if speed shifts quickly," Berg said. "An hour off in a forecast can make a big difference."
Wind power companies also are interested in better predictions that will help them choose the best sites for wind farms. They study sites extensively before building, but forecasting winds at the height of turbines is an evolving field.
Because of that industry, 3TIER of Seattle and WindLogics of St. Paul, Minn., are collaborating with Newsom and Berg on their research. The companies, which help wind power developers identify and evaluate potential locations for wind farms, are serving as consulting and advising on what types of data would be most useful.
Data collection began this winter and will continue through mid-summer.
Annette Cary: 582-1533; acary@tricity herald.com.