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It is now well established that rate of leakage of water is directly related to the distribution pressure in a network. In this context, pumps can consume up to 60% of the overall energy requirement in the case of pressure driven demand whereby they are solicited for direct supply. In this paper, we investigate the energy efficiency of distribution in an experimental network which is embedded with two levels of leakage (low and high) using three different methods. They are analysed and compared in terms of specific energy consumption and rate of leakage. A novel concept known as the Harmonic Oscillator Tank has been developed whereby the conventional hydropneumatic tank is pressure modulated so as to produce a constant output flowrate within the presence of leaks. Experimental results show that the throughput of the Harmonic Oscillator Tank for a heavy leaking network is highest (86.45%) with the lowest percentage leakage of 13.5% at a specific energy consumption of only 0.354 kWh/m3/day when compared to the other two schemes namely direct pumping and pumping through a variable speed drive in a loop. This Harmonic Oscillator Tank opens up new avenues for reducing energy and leakage in old damaged networks whereby a short or medium-term solution is often required since infrastructure renewal requires time and a massive investment.

A power distribution system includes sectionalizing switches and tie switches. Sectionalizing switches are normally closed switches while tie switches are normally open switches. By changing the status of the switches, an optimal configuration can be obtained such that the real power loss in the system is minimum. In this paper, a music based metaheuristic algorithm was applied to the Distribution Network Reconfiguration Problem to minimize real power losses. The Harmony Search Algorithm is presented in the paper and its application to the Distribution Network Reconfiguration problem is described. Simulation results are presented for 4 test systems: 16-bus, 33-bus, 70-bus system and a local Mauritian system. Optimal configurations were obtained in all cases. (6 pages)

Modelling real distribution networks can be particularly difficult if they are so leaky that the types of leak and their nature can hardly be determined from scarce field measurements. In this context, a new approach to model development of such WDNs is proposed. The method is based on leakage estimation from MNF and the burst frequency of AZPs. After applying it to a real DMA in Mauritius, the resulting calibrated model from EPANET is found to approach the actual status of the network very closely in terms of overall real losses, coefficients of discharge, nodal flow and pressure.