Feasibility study for maximum demand control on the central division of Queensland Railways

Queensland Railway (QR) has electrified its Central Queensland Track servicing the mines west of Rockhampton and Mackay. The traffic task annually consumes 202×10⁶ kWh of electrical energy for the Goonyella system and 161×10⁶ kWh for the Blackwater system resulting in an annual electricity cost of A$29M. The existing tariff structures provided two usable tariffs; a time of use energy consumption tariff and a time of use two-part demand tariff. Considering the level of consumption and maximum demand, it became obvious to QR that minimising the upper limit of the maximum half-hour demand for the total system could save substantial annual electricity costs. This is by virtue of maintaining the load factor as high as possible and making best use of the two-part demand tariff. The authors discuss strategies to reduce and control the maximum half-hour demands