Solar Drinking Water Supply on the Pasture

Abstract

Agriculture opens up various possibilities for the use of photovoltaic sy- stems, especially for the supply of water to plants and animals at loca- tions which are far from the mains. Practical examinations lasting se- veral years show that photovoltaic pump systems on pastures remote from the mains can guarantee the supply of water to cattle reliably and even economically. However, this requires that the performance para- meters of the pump and the water consumption of the animals are known and well coordinated, i.e. that the system is optimally dimensioned. In the following contribution, the results of several years of pump tests and measurements of the water consumption of grazing cattle are pre- sented, and conclusions with regard to the dimensioning of photovoltaic pasture drinkers are drawn. Under the climatic conditions in Central Europe, an installed power of only 1 to 2 watts per head of non-lactating cattle and per metre of height difference is required during the summer months. Furthermore, operational experiences and costs of PV drinkers for cattle used in practice are reported on. Optimally dimensioned PV pasture drinkers can supply drinking water at less than a quarter of the expense caused by conventional drinking water systems.