Photovoltaic-powered Water Pumping for Small Irrigation Systems

Abstract

A 374-peak wattp,SOC* photovoltaic (pv) array was connected through a 0.4 kW (0.5 hp) DC permanent magnet motor to a single-stage centrifugal pump to demonstrate the water pumping capacity of this system and to analyze the economic competitiveness of pv power for micro-irrigation in Florida. During the eight-month time period in which it operated, a datalogger monitored the systems efficiencies under a variety of climatic conditions. These data points were used to create an irradiance dependent, empirical mathematical model of the pv system. Ten years of solar irradiance data were applied to this model to generate a 12-month performance curve for the system. These daily values of water pumped were compared to the daily potential evapotranspiration (ETp) calculated from the same weather data using the Penman equation. Under assumed soil conditions, the land area on which the pv system could replace the ETp with a reliability of 0.84 was 1.06 ha (2.62 ac) for the Florida vegetable growing season (September-May).