A. Marcus (Ed.): DUXU 2014, Part III, LNCS 8519, pp. 530–541, 2014. © Springer International Publishing Switzerland 2014 User-Centred Design of an Audio Feedback System for Power Demand Management Rebecca Ford 1 , Joe Penn 2 , Yu-Chieh Liu 2 , Ken Nixon 2 , Willie Cronje 2 , and Malcolm McCulloch 3 1 School of Engineering and Computer Science Victoria University of Wellington PO Box 600, Wellington, 6140, New Zealand rebecca.ford@ecs.vuw.ac.nz 2 School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg, Private Bag 3, WITS, 2050, South Africa joseph.penn@students.wits.ac.za, {yu-chieh.liu,ken.nixon,willie.cronje}@wits.ac.za 3 Department of Engineering Science, University of Oxford Parks Road, Oxford, OX1 3PJ, United Kingdom malcolm.mcculloch@eng.ox.ac.uk Abstract. Low-income houses in South Africa are supplied with a pre-payment meter and a circuit breaker that trips at a low power level (about 20A, 4.5kW), resulting in many nuisance trips. Four categories of audio cues, each being able to represent five levels of power consumption, are assessed. A survey of 62 people was conducted. The numerical analysis of the results and the perceptions of the respondents both indicate that the use of changing tempo and texture is the most effective at conveying feedback information on the power consumption in the home. Keywords: audio cues, demand management, low cost, energy feedback. 1 Introduction This paper addresses the issue of developing a design methodology for providing immediate and intuitive audio feedback about high power consumption to low-income residential users, particularly for periods when their demand is approaching the maximum capacity of the main circuit breaker in their home. On any electrical power system (national grid, microgrid or nanogrid) it is extremely important that the flow of power between generators and loads is balanced at any instant in time. This ensures stable operation of the system and avoids the disruption that will ensue if the grid is blacked out due to instability. Stability can be addressed from the generation side as well as the consumption side. An adequate reserve margin on the generation side (embodied in the kinetic energy of the spinning turbo-generators, or stored battery charge on microgrids) gives the grid operators the freedom to dispatch more energy from the generators to the load side at short notice. South Africa in particular is facing severe generation constraints at the present