Photovoltaic Water Pumping System For Irrigation Research Articles

Dynamic mathematical model design of photovoltaic water pumping systems for horticultural crops irrigation: A guide to electrical energy potential assessment for increase access to electrical energy

Abstract In developing countries where most population does not have access to the conventional electricity network and depends on agriculture for their subsistence, the agricultural sector has been negatively affected by the low coverage of the national energy network in areas with potential for irrigation. The low index of the population with access to electricity leads to the development of affordable and clean energy for agricultural and domestic uses. Photovoltaic water pumping systems for irrigation (PVWPSI) have been widely used to increase access to energy for irrigation in many countries and several models' design are being developed to improve their performance and deployment. However, during the PVWPSI design, many of the existing models’ somehow fail by considering the water demand as constant throughout crops productive cycle. In this paper, a new dynamic mathematical model design of PVWPSI is presented as a guide tool to electrical energy potential assessment for irrigation and supply other energy demands through the horticultural crops water demand characteristic in its different development phases. In this context, a PVWPSI design is made, using as a case study a typical 0.5ha for tomato production in Boane district, Mozambique. The results show that, generally horticultural crops have four development phases. Yet, PVWPSI should be sized according to the crop development phase, whose water demand is maximum. The tomato sizing phase is the flowering, and the daily averages surplus electrical energy in the system in the four tomato development phases, after irrigation, are 5.02 kWh, 2.87 kWh, 1.02 kWh, and 2.55 kWh, that can be saved and redirected to cover other electrical energy needs.

Design and Performance of Photovoltaic Water Pumping Systems: Comprehensive Review towards a Renewable Strategy for Mozambique

The use of solar photovoltaic (PV) technology for water pumping systems (WPS) has been one of the most popular forms of solar energy application in recent decades in remote and desert areas, as well as in some urban areas. In this article, an advanced literature review on the design and performance of solar technology for water pumping is presented, exploring also the best perspective of transition for the developing countries energy needs. Additionally, this paper intends to analyze the Mozambique’s perspective on renewable energy technologies setting the Mozambican scenario regarding photovoltaic water pumping systems (PVWPS) technology with the aim to identifying the main knowledge of PVWPS design and research gap. The results show that the most commonly used configuration of PVWPS technology is direct coupling systems without battery storage. These systems are simple and reliable, mainly used in small-scale pumping for small irrigations and domestic use. The mainly variables that influence the performance of PVWPS are: total dynamic head, quantity of fluid extracted, variation of solar radiation level, PV and motor pump technology. Yet, the efficiency of the PV and overall system does not exceed 10% and 5%, respectively. Looking at the designing, mathematical models, software-assisted is being predominant. Yet, as research gap, it is possible to understand from different authors that the dynamic nature of the end-use of PVWPS is not explored on methodology design of PVWPS, and the techno-economic optimum system configuration is not always the one that gives the highest annual system efficiency. For the Mozambican’s context, PVWPS for irrigation has been expanding slowly but has gained expression since 2013. In turn, static models based on software of pump manufacturers for PVWPS design are the most widely used in Mozam-bique. In Mozambique, PVWPS match the perspective of different researchers regarding the availability of solar resource, boreholes and amount of water required for irrigation. The adoption of PVWPS is a means of increasing the sustainability of the rural communities.