Photos placed in horizontal position with even amount of white space between photos and header Characterization of wind velocity distributions within a full-scale heliostat field Jeremy Sment, Graduate Intern, NSTTF Clifford K Ho Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a w holly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy s National Nuclear Security Administration under contract DE-AC04-94AL85000.
Presentation Overview Introduction (1 min): Commercial Scale Concentrating Solar Technologies Costs and Hurdles, i.e. Why are we doing this? Wind Profile Goals (3 min) Meteorological Wind Loading Model Validation Initial Results (5 min): STOW Configuration 45 Configuration Summary of Future Test Goals (1 min): 2
Concentrating Solar Technologies Point Focus: Solar Dish Stirling Energy Systems: 31.25% solar to grid efficiency Credit: Sandia National Laboratories/Randy Montoya Copyright: SNL 2008 Location: SNL 3
Concentrating Solar Technologies Line Focus: Parabolic Trough SkyFuel, Inc Credit and Copyright: Skyfuel Inc, 2009 Location: Albuquerque, NM 4
Concentrating Solar Technologies Point Focus: Central Receiver Tower with Heliostat Field Solar Two 10MW Plant (1996-1999) 1,818 heliostats Credit and Copyright: Sandia National Laboratories, 1996 Location: Barstow, CA 5
How a Solar Power Tower Works Direct Steam (esolar Lancaster, CA 5MW) Molten Salt Storage (SolarReserve Tonopah, NV 110MW) Power Plant Schematic Credit and Copyright: DOE/NREL 1996 6
Costs and Hurdles Heliostats typically contribute ~50% of total plant cost $164/m 2 installed given 5,000/yr R & D should be able to reduce the heliostat price by $17/m 2 Drives and pedestal account for 30% of total materials cost Understanding wind forces and torques can inform possible low cost redesign of Azimuth drives. Winsmith stated that the design of their azimuth drive may be too conservative and that a less-costly drive might be possible with better understanding of wind loads and torques on drive. Improvements in optical performance can result in same power production with a reduction in field size and heliostat area. Source: Gregory J. Kolb 2007, Sandia National Labs Heliostat Cost Reduction Study. SAND2007-3293 7
Presentation Overview Introduction (1 min): Commercial Scale Concentrating Solar Technologies Costs and Hurdles, i.e. Why are we doing this? Wind Profile Goals (3 min) Meteorological Wind Loading Model Validation Initial Results (5 min): STOW Configuration 45 Configuration Summary of Future Test Goals (1 min): 8
Wind Profile Goals: Meterological Meteorological Approaching Wind Velocity Speed Azimuth Elevation Power Law coefficient Site-Terrain Roughness coefficient Turbulence Intensity Gust Frequencies IU z U U z R U z z z r 9
Wind Profile Goals: Wind Loads Wind Load Coefficients C m M Q A L r r r, C f F Q A r r Q r 1 2 U 2 r Loading with Wind-Loading without Wind 10
Wind Profile Goals: Model Validation Model Validation Boundary Velocity Inputs Perimeter heliostat Response Inner Field and close range velocity inputs Inner field heliostat response 11
Presentation Overview Introduction (1 min): Commercial Scale Concentrating Solar Technologies Costs and Hurdles, i.e. Why are we doing this? Wind Profile Goals (3 min) Meteorological Wind Loading Model Validation Initial Results (5 min): STOW Configuration 45 Configuration Summary of Future Test Goals (1 min): 12
Experimental Set-Up National Solar Thermal Test Facility, Sandia National Labs 13
Experimental Set-up Field Mounted Anemometers F1-23 F2-17 F3-11 Heliostat-Mounted Anemometers H1-20 H2-18 H3-17 H4-15 Solar Two 10MW Plant 14
Experimental Set-up Solar Two 10MW Plant Cut plot of mesh used on 45 configuration with 1.8 million cells. Heliostat is rotated 20 in azimuth from plane of cut plot. 15
Wind Profile: STOW, 21 mph Empirical Wind Speed Modeled Wind Speed 18 mph 17 mph 16 mph 15 mph 20 mph 20 mph 20 mph 20 mph STOW Position with Boundary Wind Speed 20 mph Height Measured Modeled Relative Turbulence (in) (mph) (mph) Error % Intensity % 80 18 ± 5 20 ± 1 0-62 28 60 17 ± 5 20 ± 1 0-45 29 40 16 ± 6 20 ± 1 0-55 31 20 15 ± 5 20 ± 1 0-55 33 16
Wind Profile: 45 Position Empirical Wind Speed Modeled Wind Speed 18 mph 17 mph 17 mph 15 mph 19 mph 18 mph 18 mph 17 mph 45 Position with Boundary Wind Speed 20 mph Height Measured Modeled Relative Turbulence (in) (mph) (mph) Error % Intensity % 80 18 ± 3.5 19 ± 1 0-27 19 60 17 ± 3.5 18 ± 1 0-29 21 40 17 ± 3.5 18 ± 1 0-29 21 20 15 ± 3.5 17 ± 1 0-39 23 17
Wind Profiles Sample Wind Velocity Measurements 18
speed (mph) Speed Profile: FACE-UP Position Wind speed distributions by anemometer location: STOW Overall Statistics Min 3.46713 Mean 17.89215 Max 36.60821 Pooled Std Dev 5.086162 Spread by Anemometer Min 6.688937 5.459309 7.361076 8.830017 7.586691 5.530745 3.46713 Mean 20.90128 Max 36.60821 18.81197 33.7443 18.18218 32.51908 18.47038 35.42621 17.2312 33.45851 16.45911 34.45718 15.18891 29.85555 Std Dev 5.485127 4.898864 4.790864 5.098775 4.875733 5.716192 4.647613 40 30 20 10 0 F1 F2 F3 H1 H2 H3 H4 anem. location 19
wind heading (deg) Direction Profile: FACE-UP Position Wind heading distributions by anemometer location: STOW Overall Statistics Min 135.7482 Mean 196.555 Max 248.837 Pooled Std Dev 12.68931 Spread by Anemometer Min 153.1756 138.3745 135.7482 160.7641 157.4727 152.3154 149.571 Mean 196.5374 Max 228.9087 187.778 225.5666 192.6431 228.4576 198.1136 238.824 199.245 244.1302 202.5686 248.837 198.9995 244.8459 Std Dev 10.74818 11.57884 12.97564 12.18747 13.5688 13.62521 13.81583 250 225 200 175 150 125 F1 F2 F3 H1 H2 H3 H4 anem. location 20
wind elevation (deg) Elevation Profile: FACE-UP Position Wind elevation distributions by anemometer location: STOW Overall Statistics Min -25.6342 Mean -0.83141 Max 45.80261 Pooled Std Dev 6.060944 Spread by Anemometer Min -17.573-18.2739-19.9922-21.2767-25.6342-18.8664-20.7207 Mean -0.23591 Max 34.629-1.53254 29.13803-1.17643 22.01511-0.73816 24.0178-3.03232 23.96555 2.309696 45.78886-1.41418 45.80261 Std Dev 5.596209 5.325706 5.1374 6.356434 5.90569 6.052771 7.691181 60 40 20 0-20 -40 F1 F2 F3 H1 H2 H3 H4 anem. location 21
speed (mph) Wind Profile: 45 Position Box plot of Speed distributions by anemometer location (45deg) Overall Statistics Min 5.990991 Mean 18.56332 Max 33.4794 Pooled Std Dev 3.510077 Spread by Anemometer Min 13.31466 9.857152 9.545729 6.951105 6.490492 5.990991 6.911933 Mean 23.48744 Max 33.4794 19.95667 29.62636 19.31882 29.40307 18.42811 29.09159 16.67049 27.99668 16.58596 31.02835 15.49578 28.25207 35 30 25 20 15 10 5 F1 F2 F3 H1 H2 H3 H4 anem. location 22
wind elevation (deg) Wind Profile: 45 Position Box plot of wind elevation distributions by anemometer location (45deg) Overall Statistics Min -23.7744 Mean 6.897162 Max 56.72939 Pooled Std Dev 5.818574 Spread by Anemometer Min -12.3623-16.4228-19.7085-7.10828-14.0309-7.86416-23.7744 Mean 0.036673 Max 20.62538-3.45746 24.26767-4.51279 16.99808 14.36101 39.49445 12.23795 36.21848 19.45079 56.72939 10.16396 45.80261 60 40 20 0-20 -40 F1 F2 F3 H1 H2 H3 H4 anem. location 23
Presentation Overview Introduction (1 min): Commercial Scale Concentrating Solar Technologies Costs and Hurdles, i.e. Why are we doing this? Wind Profile Goals (3 min) Meteorological Wind Loading Model Validation Initial Results (5 min): STOW Configuration 45 Configuration Summary of Future Test Goals (1 min): 24
Future Test Goals Wind Loads on Perimeter Heliostats Wind Velocity Profiles Across Full Field Wind Loads on Inner Heliostats Gust Frequency Correlations to Heliostat Modal Vibrations 25
Questions? 26