Faculty of Science and Engineering Department of Physics and Astronomy Wind Prediction Modelling and Validation Using Coherent Doppler LIDAR Data Muhammad Omer Mughal This Thesis is presented for the degree of Doctor of Philosophy of Curtin University July 2016 1 DECLARATION To the best of my knowledge and belief this thesis contains no material previously published by any other person except where due acknowledgement has been made. This thesis contains no material which has been accepted for the award of any other degree or diploma in any university. Muhammad Omer Mughal Signature……………… Date 30/11/2016 II Table of Contents Acronyms ....................................................................................................... VIII List of Figures ................................................................................................. XII List of Tables .............................................................................................. XVIII Abstract ......................................................................................................... XXI List of Publications ....................................................................................... XXV Chapter 1 Introduction .......................................................................................... 1 1.1 Status of Wind Energy Modelling and Management .......................... 5 1.2 The Research Opportunity ................................................................. 7 1.3 The Numerical Modelling Strategy for Wind Forecasting .................. 8 1.4 Field Measurements and Verification Program ................................ 10 1.5 Problem Definition .......................................................................... 11 1.6 Research Questions ......................................................................... 13 1.7 Summary ......................................................................................... 13 Chapter 2 Progress in Wind Energy Numerical Modelling and Validation ...... 14 2.1 Introduction ..................................................................................... 14 2.2 Predicting the Wind ......................................................................... 14 2.2.1 Diagnostic Modelling ...................................................................... 15 2.2.2 Prognostic Modelling ...................................................................... 15 2.2.3 Model Selection .............................................................................. 16 2.2.4 Data Assimilation ............................................................................ 17 2.2.5 Employing 4DVAR to Retrieved Wind from CDL .......................... 19 2.2.6 The Wind Profile Power Law .......................................................... 20 2.3 Evolution of Forecasting Methodologies ......................................... 20 2.3.1 Development and Current Trends .................................................... 20 2.3.2 Future Prospective ........................................................................... 22 2.4 Status of LIDAR Technology for Wind Field Assessment ............... 23 III 2.4.1 Development and Current Trends .................................................... 23 2.4.2 Future Prospective ........................................................................... 26 2.5 Summary ......................................................................................... 27 Chapter 3 Lake Turkana Wind Energy Farm .................................................... 28 3.1 Introduction ..................................................................................... 28 3.2 Topography and Climatology .......................................................... 29 3.3 Conventional Wind Resource Assessment ....................................... 31 3.4 Conventional Wind Assessment Uncertainty ................................... 32 3.5 Wind Resource Assessment using Active Remote Sensing .............. 34 3.5.1 Implementation of CDL in Wind Resource Assessment ................... 34 3.5.1.1 Wind Tracer CDL............................................................................ 35 3.5.1.1.1 Operating Principle ......................................................................... 35 3.5.1.1.2 Data Acquisition.............................................................................. 37 3.5.1.2 Elements Affecting Precision of CDL .............................................. 38 3.6 Meteorological Mast Measurements ................................................ 41 3.6.1 Data Quality Control ....................................................................... 43 3.6.2 Measured Wind Statistics ................................................................ 44 3.6.2.1 Kalkumpei Mast .............................................................................. 44 3.6.2.2 Nyiru Mast ...................................................................................... 44 3.6.2.3 Sirima Mast ..................................................................................... 45 3.7 LIDAR Wind Measurements ........................................................... 50 3.7.1 Scanning Strategy ............................................................................ 50 3.7.2 Filtering Poor Quality data .............................................................. 52 3.7.3 Wind Vector Retrieval ..................................................................... 52 3.7.4 Volume Velocity Processing Algorithm .......................................... 53 3.7.5 Generation of Wind Map ................................................................. 55 3.8 LIDAR Measured Wind Characteristics........................................... 56 IV 3.8.1 CDL and Mast Observed Wind Speed Comparison Uncertainties .... 59 3.8.2 Terrain-Following Wind Speed Plots ............................................... 60 3.9 Summary ......................................................................................... 62 Chapter 4 Wind Forecasting (WRF) Model ....................................................... 64 4.1 Introduction ..................................................................................... 64 4.2 WRF Model Description ................................................................. 66 4.3 WRF Software................................................................................. 66 4.3.1 WPS ................................................................................................ 67 4.3.1.1 Projections and Domain Resolution ................................................. 68 4.3.2 Nesting ............................................................................................ 69 4.3.2.1 One Way Nesting Its Restrictions and Applications ......................... 71 4.3.2.2 Two-Way Nesting its Restrictions and Applications ........................ 72 4.3.3 Terrestrial Data (Static Data) ........................................................... 74 4.3.4 Meteorological Initialization Fields (Dynamic Data) ....................... 74 4.3.5 GEOGRID ...................................................................................... 75 4.3.6 UNGRIB ......................................................................................... 75 4.3.7 METGRID ...................................................................................... 75 4.3.8 REAL .............................................................................................. 76 4.3.9 ARW Solver .................................................................................... 76 4.3.9.1 ARW Solver Control File ................................................................ 81 4.3.10 Domain Configuration ..................................................................... 83 4.3.11 Physical Options.............................................................................. 85 4.3.12 Influence of Different Initialization Fields ....................................... 88 4.3.13 Ingesting Satellite Data .................................................................... 90 4.3.14 Terrain complexity .......................................................................... 90 4.4 Model Validation ............................................................................ 91 4.5 WRF Post Processing Software ....................................................... 93 V 4.5.1 Plot_WRF ....................................................................................... 93 4.5.2 NCAR Command Language (NCL) ................................................. 93 4.5.3 Grid Analysis and Display System (GRADS) .................................. 94 4.5.4 Integrated Data Viewer (IDV) ......................................................... 95 4.6 Summary ......................................................................................... 95 Chapter 5 WRF Implementation and Sensitivity Analysis ................................ 97 5.1 Introduction ..................................................................................... 97 5.1.1 Design of Simulations ..................................................................... 97 5.1.2 Establishing WRF Performance in a Well-Defined Meteorological Environment .................................................................................... 97 5.2 Results and Discussion .................................................................... 98 5.2.1 Establishing the Performance WRF in a Well-Defined