NOAA-DOE Study Examined The Physics Of Wind In Complex
Terrain
New research on wind behavior in
complex terrain, led by NOAA and the U.S. Department of Energy, will improve
forecasts for wind energy firms by 15-25 percent, and improve wind
forecasts for the entire country, scientists said.
The Wind
Forecast Improvement Project 2,
or WFIP2, focused on improving NOAA’s short-term weather forecasts of wind
speeds in areas such as mountains, canyons, and coastlines, landforms often
associated with abundant wind energy potential.
The project was based in the windswept Columbia River Gorge in Washington and Oregon, where wind farms can generate as much power as five 800-megawatt nuclear power plants.
The project was based in the windswept Columbia River Gorge in Washington and Oregon, where wind farms can generate as much power as five 800-megawatt nuclear power plants.
Researchers collected 18 months of
data to better understand how terrain and weather physics affect forecasts of
wind speed and turbulence at the height of wind turbines, data that researchers
then used to improve the High Resolution Rapid Refresh (HRRR) short-term
weather model’s representation of low-level winds.
The scope of the project was unprecedented, with more than 200 instruments deployed across 50,000 square kilometers.
The scope of the project was unprecedented, with more than 200 instruments deployed across 50,000 square kilometers.
“This is a comprehensive
investigation of winds in complex terrain,” said Dave Turner, manager of the
NOAA Global
Systems Division’s Atmospheric Science for Renewable Energy Program.
“It gives us a unique opportunity to evaluate how well the HRRR represents weather in challenging conditions, and has already led to improvements in our ability to forecast low-level winds. And we’re just scratching the surface - additional work will certainly lead to further forecast improvements.”
“It gives us a unique opportunity to evaluate how well the HRRR represents weather in challenging conditions, and has already led to improvements in our ability to forecast low-level winds. And we’re just scratching the surface - additional work will certainly lead to further forecast improvements.”
The Columbia River Gorge is a deep
canyon carved by the Columbia River stretching for more than 80 miles from high
desert through the Cascade Range.
The dramatic topography of the gorge creates highly variable wind conditions - weather fronts, mountain waves, topographic wakes, thunderstorm outflows, cold pools and marine pushes - either triggered or amplified by the terrain, which impact how much electricity wind turbines can generate.
The dramatic topography of the gorge creates highly variable wind conditions - weather fronts, mountain waves, topographic wakes, thunderstorm outflows, cold pools and marine pushes - either triggered or amplified by the terrain, which impact how much electricity wind turbines can generate.
Once the field project ended in
2017, the researchers produced a comprehensive dataset of meteorological
processes that allowed NOAA modelers to solve a problem that had long vexed
grid operators: more accurate predictions of the transition between cold,
stable air to windy conditions, transitions that often result in a surge of
power generated by wind turbines.
Previously, weather models have been too aggressive in their predictions, resulting in over-estimates of power surges and false alarms for wind ramp-ups.
Previously, weather models have been too aggressive in their predictions, resulting in over-estimates of power surges and false alarms for wind ramp-ups.
Data collected during WFIP 2 allowed
a NOAA modeling team to improve wind forecasts by 15-25 percent depending on
weather conditions, with the best results in the winter when cold pools are
more common.
The models used for the project were
the 13 km grid Rapid Refresh (RAP) model, the 3 km grid High-Resolution Rapid
Refresh (HRRR) model, and a 0.75 km nest within the HRRR that provide
high-resolution forecasts.
“The improvements to NOAA’s HRRR model made by
WFIP2 are helping Vaisala to better forecast energy output for wind projects
both before and after they are built,” said Pascal Storck, director of
renewable energy for Vaisala, Inc. “The focus on a publicly available model
means that these benefits are reaching the entire industry.“
Researchers demonstrated that the
updated HRRR, which incorporated changes resulting from the WFIP2 analysis,
also improved wind forecasts in other regions across the United States.
This new version of HRRR became operational at NOAA’s National Center for
Environmental Prediction in July 2018.
“WFIP2 is an excellent example of a
successful end-to-end research program,” said Jim Wilczak, a senior scientist
on the NOAA Physical
Sciences Division Boundary Layer Observations and Processes Team. “We collected observations, used them to better understand
the meteorological processes affecting the local weather, and then used that to
improve our weather prediction models - and forecast skill.”
Led by NOAA and the Department
of Energy, WFIP2 brought together
researchers, instruments and other resources from the NOAA Earth System
Research Laboratory, CIRES, the NOAA Air Resources Laboratory
Field Research Division, multiple DOE laboratories, Vaisala Inc., and other
private companies, and universities.
For more information, contact
Theo Stein, NOAA Communications , at (303) 497-6288 or
theo.stein@noaa.gov.