1. 5/18/2015Air Resources Laboratory Boundary –Layer Dispersion NOAA/ATDD - Duke Energy Cooperative Research and Development Agreement Joint Wind Energy Program: Atmospheric Velocity Gradients Will Pendergrass NOAA/ARL/ATDD OAR Senior Research Council Meeting Oak Ridge, TN August 18-19, 2010

2. 5/18/2015Air Resources Laboratory (1) Can the forecast of wind turbine hub-height wind speeds be improved through inclusion of near- neutral and unstable flux-gradient wind modeling techniques? (2) What is the uncertainty associated with high resolution WRF mesoscale in both now-cast and forecast of winds at 10 m and hub-height? (3) Does assimilation of surface energy flux measurements (heat flux, shear stress, surface roughness, displacement height, and mixed layer height) improve mesoscale forecasts through mesoscale model land surface exchange methodologies? (4) What is the impact of spatial variability in surface energy-balance on forecasted gradient winds at 10 m and hub-height? Science Questions NOAA/DUKE CRADA Goal: Improved Forecasts of Hub Height Winds

3. 5/18/2015Air Resources Laboratory NOAA/DUKE CRADA Forecast Confidence Level

4. 5/18/2015Air Resources Laboratory field measurements mesoscale modeling Phase one (1) is an evaluation of the flux gradient velocity profile technique based on directly measured surface energy balances. Phase two (2) is an evaluation of results from Phase one as implemented in the WRF model through alternative land use model parameterizations. Boundary-Layer Velocity Gradient Program NOAA/DUKE CRADA Velocity Gradient Profile Monin-Obukov Stability

5. 5/18/2015Air Resources Laboratory Based on conversations between NOAA/ATDD and Duke Energy, the Ocottilo wind farm was selected as the initial focused study area. During a joint site survey, NOAA/ATDD and Duke Energy engineers evaluated the Ocotillo area for installation of a NOAA 10-meter energy balance system and 30- meter wind/temperature profiling system. Additional siting was evaluated for Doppler SODAR operation, additional surface based energy-balance system, and possible radiosonde operations. Site Selection Big Spring, Texas Duke Energy Ocotillo Wind Farm NOAA/DUKE CRADA Prevailing winds

6. 5/18/2015Air Resources Laboratory In cooperation with Duke Energy field engineers, NOAA/ATDD install a 30- meter tower monitoring winds and temperature within the surface roughness layer. Wind Flux Profiling Tower Acquired Observations 15, 30, 60 minute output u, v, w, ws, wd σ u, σ v,σ w, u’v’, u’w’, v’w’, T, T’ 2, w’T’, u’ 2, v’ 2, w’ 2, u run, v run, w run NOAA/DUKE CRADA

7. 5/18/2015Air Resources Laboratory In cooperation with Duke Energy field engineers, NOAA/ARL installed a 10-meter energy balance monitoring system NOAA/DUKE CRADA 15, 30, 60 minute output u, v, w, ws, wd σ u, σ v,σ w, u’v’, u’w’, v’w’, T, T’ 2, w’T’, u’ 2, v’ 2, w’ 2, u run, v run, w run, soil temperature (5 levels), soil moisture, solar energy components, surface temperature, CO 2 /H 2 O Surface Energy Balance system

8. 5/18/2015Air Resources Laboratory NOAA/ATDD established a web-based data management site to provide both NOAA/ATDD and Duke Energy with access to acquired measurements from both the Energy balance system 8 NOAA/DUKE CRADA

9. 5/18/2015Air Resources Laboratory9 WRF Model Output NOAA/DUKE CRADA

10. 5/18/2015Air Resources Laboratory NOAA/DUKE CRADA Gradient profile Requirements: U *, z 0, h, z/L Observed Duke Energy Ocotillo 80 m winds Evaluated Ocotillo gradient profile parameters

11. 5/18/2015Air Resources Laboratory NOAA/DUKE CRADA Intercomparison of forecast/measured winds and temperature RTMA – red ATDD - black Wind Speed Wind Direction Temperature

12. 5/18/2015Air Resources Laboratory Technical Interchange Meetings (TIMs) : Researchers from NOAA/ARL and Duke Energy have planned routine (TIMs) to review collaborative efforts (next meeting late September, 2010). Evaluation/comparison of measured Duke Ocotillo 80-meter winds using measured e-balance surface winds and boundary layer variables using basic velocity gradient profile methodologies. Evaluation/comparison of measured Duke Ocotillo 80-meter winds using RTMA and WRF forecast surface winds and boundary layer variables using evaluated basic velocity gradient profile methodologies. Late Summer-2010 study intensive – measurement of vertical profiles using Doppler Sodar, evaluation of CTW lidar, and high frequency spectral wind measurements. 12 Next Steps NOAA/DUKE CRADA