Solar Water Pumping — An Analytical Overview

Abstract

Two basic thermodynamic conversion techniques of solar water pumping are recognized. In the first technique, a high internal energy fluid heated in a solar collector is used to power a conventional heat engine which drives a conventional pump. The second technique involves specially designed solar pumps, for example the Boldt, Rao and Michaelis designs. The study reveals that an engine working on the organic Ranking cycle and having an output of a few kilowatts (maximum 20KW) would be most suitable for pumping purposes. It is also concluded that a pumping rate of 2-3 cubic meters per hour is obtainable for every square meter of the flat plate collector area in an engine employing Freon-11 as the working fluid.