Effects of Solar Powered Aquaculture-Irrigation System to the Growth and Yield of Rice


Solar pumping for irrigation is gaining popularity in the Philippines. However, this system is expensive and water storage was unutilized for aquaculture. The study intended to develop and optimize a small scale solar-powered irrigation and aquaculture system for rain-fed rice fields by the establishment of appropriate motor size to drive the pump, determination of solar panel tilt and comparison with traditional irrigation pumping. The system was composed of a positive displacement type solar pump, photovoltaic panels, charge controller, battery and elevated lined water impounding for aquaculture. A calculated tilting angle, ±5 and ±10 degrees of the computed were tested by measuring the current drawn by the photovoltaic panels. Three motor sizes were used, their flow rate and volume of water pumped per 1 full-charged of a 100Ah battery were measured. Also, the effect of the water impounded and raised with tilapia to the growth of rice was determined. The economic feasibility of the system was calculated. Results revealed that the 200-watt motor can pump more water per 1 full-charged of a battery. The monthly computed panel tilt has the highest harvested energy. Furthermore, irrigated rice with water used in aquaculture of tilapia had a higher yield compared to water pumped by the diesel pump from a well. The system has a benefit-cost ratio of 1.26 and a payback period of 2.87 years.