WIND RESOURCE POTENTIAL FOR ELECTRICITY GENERATION USING MICRO - HYBRID SYSTEMS IN NORTHERN KENYA By DAVID MURITHI NJIRU N50/CTY/PT/20701/2012 A Thesis Submitted in Partial Fulfilment of the Requirement for the award of the Degree of Master of Environmental Science in the School of Environmental Studies of Kenyatta University May 2017 DECLARATION This thesis is my original work and has not been presented for a degree in any other university or any other award. DAVID MURITHI NJIRU (Bsc. Meteorology) N50/CTY/PT/20701/2012 SIGNITURE………………………………….. DATE ……………………………. Declaration by Supervisors I/we confirm that the work reported in this thesis was carried out by the student under my/our supervision. NAME: Dr. GATHU KIRUBI Department of Environmental Sciences Kenyatta University SIGNITURE: ……………………………. DATE: ………………………….. NAME: Dr. EZEKIEL NDUNDA Department of Environmental Sciences Kenyatta University SIGNITURE: ……………………………. DATE: ………………………….. ii DEDICATION I dedicate this Research report to my late Mum (Wanjira Njiru) who inspired me to work hard in school for the fruits of education are always sweet and their taste lingers longer than short time pleasures. iii ACKNOWLEDGEMENT I am a very grateful to my lecturers at Kenyatta University (KU) who modelled me to this level. Special thanks to my two supervisors Dr. G. Kirubi and Dr. E. Ndunda for standing on their very important and busy schedules to advice and guide this research to the final end. I recognise the kind words of encouragements from by peers and work mates at the Institute for Meteorological Training and Research (IMTR) Nairobi, who always took time to enquire about the progress in my studies. Thank you very much. iv TABLE OF CONTENTS DECLARATION ..................................................................................................................... ii DEDICATION ........................................................................................................................ iii ACKNOWLEDGEMENT ..................................................................................................... iv LIST OF TABLES ................................................................................................................ viii TABLE OF FIGURES ........................................................................................................... ix ABBREVIATIONS & ACRONYMS .................................................................................... xi ABSTRACT ........................................................................................................................... xii CHAPTER ONE: INTRODUCTION ................................................................................... 1 1.1 Background to the study ................................................................................................... 1 1.2 Statement of the Problem ................................................................................................. 5 1.3 Research questions ........................................................................................................... 6 1.4 Research Objectives ......................................................................................................... 7 1.4.1 Specific objectives......................................................................................................... 7 1.5 Research hypotheses ........................................................................................................ 7 1.6 Conceptual Framework .................................................................................................... 8 1.7 Justification of the study .................................................................................................. 9 1.8 Significance of the study ................................................................................................ 11 CHAPTER TWO: LITERATURE REVIEW .................................................................... 12 2.1 Introduction .................................................................................................................... 12 2.2 Assessment of wind resource characteristics using GCM outputs and baseline data. ... 12 2.3 Global Circulation Model (GCM) .................................................................................. 14 2.4 Equitable electricity energy access and distribution of renewable energy resources .... 16 2.5 Renewable energy technologies and adoption of off-grid hybrid energy systems ........ 18 2.6 Hybrid power systems .................................................................................................... 19 v 2.7 Research Gaps ................................................................................................................ 19 CHAPTER THREE: RESEARCH METHODOLOGY .................................................... 21 3.1 Introduction .................................................................................................................... 21 3.2 The area of study ............................................................................................................ 21 3.3 Research Design ............................................................................................................. 23 3.4 Data acquisition .............................................................................................................. 23 3.5 Estimation of the wind power resource potential and the turbine height ....................... 27 3.6 Data Analysis ................................................................................................................. 28 3.6.1 Trend and significance tests ........................................................................................ 29 3.6.2 Coefficient of Variability Test and the standard error of mean (SEM) ...................... 31 3.7 Wind power density and the energy consumption per capita in northern Kenya .......... 32 CHAPTER FOUR: RESULTS AND DISCUSSIONS ...................................................... 34 4.1 Introduction .................................................................................................................... 34 4.2 Stationary test using Mann-Kendall and Spearman’s Rank Test ................................... 34 4.2.1 Test for trend and significance for winds in northern Kenya ...................................... 40 4.2.2 Seasonal trends and variability for baseline at surface and 850mb level .................... 42 4.3 Determination of spatial and temporal wind resource distribution ................................ 49 4.3.1 Long term mean wind speed distribution in at the surface and 850mb Level ............ 49 4.3.2 Seasonal wind speeds distribution at the surface in northern Kenya .......................... 53 4.3.3 Seasonal wind resource variability at 850mb level in northern Kenya ....................... 62 4.3.4 Graphical presentation for wind variability in Baseline and Projected periods .......... 65 4.3.5 Projected (2016 to 2050) wind resource distribution in northern eastern Kenya........ 68 4.3.6 Relationship between Baseline and Model outputs at Surface and 850mb ................. 77 4.3.7 Assessment of wind resource variability using Box plots........................................... 80 4.3.8 Variation of the Wind Resource Potential using Geographical Information Systems 84 vi 4.3.9 Comparison for Historical and Projected wind variability in northern Kenya ........... 88 4.4 Variation of wind speed with height using the power-law relation ............................... 90 4.4.1 Electricity energy consumption per capita in north eastern Kenya. ............................ 91 4.5 Contributions of renewable energy resources to Hybrid systems in northern Kenya. ... 96 CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS ................................ 99 5.1 Introduction .................................................................................................................... 99 5.2 Summary ........................................................................................................................ 99 5.3 Conclusions .................................................................................................................. 101 5.4 Recommendations ........................................................................................................ 103 REFERENCES .................................................................................................................... 104 vii LIST OF TABLES Table 1: Names and locations of the seven meteorological stations in Northern Kenya ......... 26 Table 2: Mann-Kendall test for mean monthly winds for Garissa station................................ 35 Table 3: Stationary tests for wind data at surface and 1500m (850mb) level .......................... 37 Table 4: Stationary test for simulated seasonal wind totals in northern Kenya ....................... 38 Table 5: Summary of winds for baseline at the surface in northern Kenya ............................. 40 Table 6: Mann-Kendall and Spearman's Rank Test for trend and significance ....................... 42 Table 7: Mann Kendall trend Test for seasonal means at the surface & 850mb level ............. 44 Table 8: Relationships between LTM and Seasonal winds for northern Kenya ...................... 45 Table 9: Lagged correlation (r) for season to seasonal winds in northern Kenya .................... 46 Table 10: Baseline and model outputs at surface and the 850mb for northern