Dynamics in rainfall patterns are posing a threat to crop production in Uganda. Irrigation can be used to ensure constant production; however, the motorized powered irrigation methods are quite costly to run in addition to being environmentally unsustainable. There is thus need for alternative irrigation methods. Renewable energy sources which are readily available can be used to power irrigation systems. This study hence sought to design an appropriate wind-solar hybrid system for irrigating 1 acre of banana plantation in Kalangala district, Uganda. Using metrological data, mean wind speed and monthly solar irradiance of global radiation horizontal for the district were analysed. A wind-solar hybrid system was optimally designed for a standalone drip irrigation system of 450 banana plants on 1-acre land with water requirement of 33.73 m3 d−1. The wind turbine was simulated to analyse for static pressure, cut plane flow behaviour, turbulence intensity and stress distribution exposed at 20 m s−1 wind speed. A cost analysis was done to estimate the total project investment, maintenance and operational cost, annual project gross income, net income stream and the annual net real rate of returns. The simulation results showed that the system could effectively operate at speeds of 20 m s−1 without deformation. The net present value of income stream for the first 5 years at r = 5% was 12,935,468 UGX with a net real rate of return of 3.5% per year. The study will, therefore, be a useful guideline in making investment decisions in hybrids irrigation systems.

中文翻译：

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设计用于小型灌溉的太阳能和风能混合系统：以乌干达Kalangala地区为例

降雨模式的变化对乌干达的农作物生产构成威胁。灌溉可用于确保恒定产量；然而，除了环境不可持续之外，电动灌溉方法的运行成本也很高。因此，需要替代的灌溉方法。随时可用的可再生能源可用于灌溉系统。因此，本研究寻求设计一种合适的风光混合系统，以灌溉乌干达加兰加拉地区1英亩的香蕉种植园。使用计量数据，分析了该地区的平均风速和每月全球水平总辐射的太阳辐照度。风能混合系统是针对1英亩土地上450棵香蕉植物的独立滴灌系统而最佳设计的，其需水量为33.73 m3 d-1。对风力涡轮机进行了仿真，以分析在20 m s-1风速下暴露的静压，切面流特性，湍流强度和应力分布。进行了成本分析，以估算项目总投资，维护和运营成本，项目年度总收入，净收入流以及年度净实际回报率。仿真结果表明，该系统可以在20 m s-1的速度下有效运行而不会变形。r = 5％的前五年的收入流的净现值为12,935,468乌干达先令，每年的实际净收益率为3.5％。因此，该研究将成为制定混合灌溉系统投资决策的有用指南。在20 m s-1风速下暴露的湍流强度和应力分布。进行了成本分析，以估算项目总投资，维护和运营成本，项目年度总收入，净收入流以及年度净实际回报率。仿真结果表明，该系统可以在20 m s-1的速度下有效运行而不会变形。r = 5％的前五年的收入流的净现值为12,935,468乌干达先令，每年的实际净收益率为3.5％。因此，该研究将成为制定混合灌溉系统投资决策的有用指南。在20 m s-1风速下暴露的湍流强度和应力分布。进行了成本分析，以估算项目总投资，维护和运营成本，项目年度总收入，净收入流以及年度净实际回报率。仿真结果表明，该系统可以在20 m s-1的速度下有效运行而不会变形。r = 5％的前五年的收入流的净现值为12,935,468乌干达先令，每年的实际净收益率为3.5％。因此，该研究将成为制定混合灌溉系统投资决策的有用指南。仿真结果表明，该系统可以在20 m s-1的速度下有效运行而不会变形。r = 5％的前五年的收入流的净现值为12,935,468乌干达先令，每年的实际净收益率为3.5％。因此，该研究将成为制定混合灌溉系统投资决策的有用指南。仿真结果表明，该系统可以在20 m s-1的速度下有效运行而不会变形。r = 5％的前五年的收入流的净现值为12,935,468乌干达先令，每年的实际净收益率为3.5％。因此，该研究将成为制定混合灌溉系统投资决策的有用指南。