Water Current Turbines

CONTENTS Foreword iii Acknowledgements List of illustrations CHAPTER 1 INTRODUCTION 1.1 The Objective of this Book 1 1.2 Water Current Turbine (WCT) Technology 2 1.3 Alternative Water-lifting Methods 2 1.4 Background 5 1-5 The S..$;ructure of this Book 5 CHAPTER 2 TECHNICAL ASPECTS River Currents as an Energy Source 6 Site Selection 12 Measurement of River Current Speed 14 Water Pumping Turbine System Design 14 Turbine Rotor 17 2.5.1 Choice of Turbine Rotor 17 2.5.2 Rotor Construction Materials 25 2.5.3 Rotor Bearings 25 Transmission 2 6 Choice of Pump 30 2.7.1 Pump Types Available 30 2.7.2 Pump Selection for 'Mark I' Machine 35 2-7.3 Pump Selection for 'LOW Cost' Machine 38 Delivery System 38 2.8.1 Pump to River Bank Pipe 40 2.8.2 River Bank to Plants 40 Floats 42 Mooring System 45 Rotor Supporting Frame 45 Rotor Lifting Bechanism 46 Storage Tank Design 46 Installation 48 Operation 5 1 Maintenance 5 2 Conclusions 53 2.17.1 Key Design Features 5 3 2.17.2 Main Technical Features which will Affect Users 53 2.1 7.3 Further Work CHAPTER 3 SOCIO-ECONOMIC ANALYSIS (by Peter Burgess) 3.1 Introduction 5 5 3.2 Assessment of the Cost-Effectiveness of Water Pumping for Irrigation 55 3.2.1 Sensitivity Analysis 6 0 3.2.2 Conclusion GO 3-3 Social Factors 6 1 393.1 Introduction 6 1 3-3.2 Size of Pumping System Relative to 6 2 Size of Landholdings 303.3 Restrictions on Water Output 64 3 . 3 .'4 Social Implications of the Differing Cost Structures of the Alternative Pumping Systems 67 3-3.5 The Effects of Constraints on Pump Siting on Land Values 70 3.3-6 Potential for Local Manufacture 7 1 303.7 Evidence for Potential IJse 7 1 3.308 Comparison with Alternative Technologies 7 1 3 4 The Relative Cost-Effectiveness of Water Current Turbines for Irrigation Compared to Alternative Pumping Methods 72 704.1 Introduction 72 3.4.2 Evidence on Comparative Irrigation Costs 74 3.5 Conclusion 77 CHAPTER 4 CONCLUSION Checklist of Key Social, Economic and Technical 8 1 Factors APPENDICES APPENDIX 1 : More Detailed Technical Information 85 1.1 Rotor Performance Comparisons 85 1.2 Rotor Bearing Loadings 88 1.3 Calculation of Transmission Ratio 89 1.4 Estimation of System Efficiency 102 1.5 Maintenance Schedule 107 APPENDIX 2 : Case Study of the Economics of Using Water Current Turbines for Irrigating Vegetable Gardens in Juba 105