Design and development of a low-cost solar powered drip irrigation system using Systems Modeling Language

Abstract

High capital costs are the primary barrier that limits the wide spread deployment of solar-powered water pumping systems, which increase energy and water efficiency compared to conventional irrigation methods. To increase the effectiveness of investments in solar-powered water pumping systems, it is necessary to sustain the-long term performance of these systems, and solutions to decrease the overall costs should be developed. In this paper, a simple but efficient, low-cost solar-powered water pumping system, which provides the necessary pressurised water to a drip irrigation system, is developed. The results from theoretical and field studies of photovoltaic panels and other components, the modelling techniques of the overall system and its components using Systems Modeling Language, are presented. The project demonstration site covers an area that is one thousand square meters comprising more than 100 trees. The site is irrigated with an automatic timer 2 h a day in the morning from June to October, which makes it possible to utilise a direct-coupled solar-powered water pumping system with a battery buffer configuration (including a maximum power point tracker). The function of the solar panels is to charge the batteries throughout the day when sunlight is available, and the power for the pump is subsequently provided by the batteries, which furnish constant voltage and enable the pump to perform at the optimum operating point. Utilisation of a battery-buffered solar-powered water pumping system instead of a commonly used direct-coupled system without batteries provides better performance because its output flow rate is not dependent on atmospheric conditions. The result is a less costly system compared to the direct-coupled solar-powered drip irrigation system, reducing the total cost of the solar-powered system by 63% and performing better overall. The cost reduction and better performance of the proposed system in this study, can boost the use of solar-powered irrigation systems in the market. Furthermore, using Systems Modeling language to model. the stated solar-powered water pumping system helps to simplify the design and implementation process by considering all inner and outer interactions and standardising the representation of a system that is expected to contribute to further studies. (C) 2015 Elsevier Ltd. All rights reserved.