Design and operation of a remote photovoltaic deep well stock-water pump

A photovoltaic-powered reciprocating pump is currently supplying water for cattle at the New Mexico State University College Ranch 25 miles northeast of Las Cruces, New Mexico. The water is pumped from a 400-foot well into a 55,000-gallon storage tank that is the reservoir for five water tanks in separate pastures. Seasonal requirements are estimated to be from 600 gallons per day in winter to 3,000 gallons per day in summer. The photovoltaic system, installed in September 1981, replaced a 7-horsepower gasoline engine. The photovoltaic system is an economically competitive alternative to operating the gasoline engine or installing a utility line for an ac motor. The system also serves as a test bed for evaluating performance of various components and optimizing system configuration. This paper includes a description of the system and its performance to date. Operation and maintenance requirements for this remote, stand-alone photovoltaic system and the different configurations tested to date are discussed.