TECHNO ECONOMIC FEASIBILITY OF IMPROVEMENTS IN EXISTING PUMPING SETS

Abstract

Pumping of ground water accounts for a major part of the energy used in agriculture. The total electric energy utilised for irrigation pumping in India at present is around 17600 million kWh and diesel consumption is around 2300 million litres annually. It is estimated that at the end of 1993, the population of diosel and electric pumpset in India will be around 6.96 million and 9.20 million against the present popu-lation of 4.40 million and 4.6 million respectively. This obviously will increase the demand for diesel and electricity. Efficient utilisation of the limited energy resources calls for the selection of the most suitable pumpsets. Tests on various states have shown that the existing pumpsets are operating at less than optimum efficiencies and there is considerable scope for improvements. The study aims to demons-trate th economic feasibility of thy: modification leading to improvement in their efficiency. Causes of low system effi-ciency of pumpset are mentioned and the economics of various remedial measures are studied. Improvements have bean carried out in one diesel and one electric pumpset installation in Roorkee Tehsil of Saharanpur district, Uttar Pradesh; The capital cost of modifications in the pumpsets are Rs. 99.00 and Rs. 2213.50. It is seen that as a r esult of modifications in the electric and diesel pumpsets on the delivery sides, (iv) the annual saving works out to be Rs.115 and Rs.595 respectively. Net yearly saving is Rs.98.89 and Rs. 557.82 respectively after recovering the annual cost of the modifications with interest rats: of 10/. per annum and life of 10 yours period. Tests on laboratory pumping units have ben conducted to determine the head loss through different fittings and corresponding energy consumptions in kwh per hectare—cm have been discussed. It is found that for a given discharge, the rate of energy saved by the pumpset due to replacement of an elbow by a large radius bend is 0.20 kwh per hectare—cm. The annual saving in the pumpeut will bu Rs.50.Q0 which is more than the annual cost of the large radius bend for life of 15 years and interest rote of 10%.