A New Solar-Powered Rice-Fish Farming System for Yield Improvement

Abstract

Rice-fish farming is widely practiced all over the world, but since some areas lack irrigation, diesel pumps are often needed. Solar-powered irrigation systems (SPIS) are considered to be a more sustainable option than traditional pumps, but are more costly to set up, limiting their use to direct rice irrigation. This study intended to integrate solar-powered pumps in the irrigation system and investigate its viability through the following: establish an appropriate motor size, determine solar panel tilt, and compare with traditional irrigation pumping. The system was comprised of a positive displacement-type solar pump, photovoltaic panels, a charge controller, a battery, and an elevated, lined water impounding system for aquaculture. Tilt angles varying between 5 and 10 degrees were tested by measuring the current drawn from the photovoltaic panels. Three motor sizes were used and compared based on flow rate and volume of water pumped per full 100Ah battery, and the effect of the water impounding system along with raising tilapia on the growth of rice was determined. Results revealed that a 200-watt motor pumps the most water per full battery charge, and that the monthly computed panel tilt had the highest harvested energy. Furthermore, solar-powered rice-fish culture gave a higher yield compared to traditional diesel-pump irrigation, and calculations on the system’s economic feasibility show a benefitcost ratio of 1.26 and a payback period of 2.87 years.