A nonintrusive appliance load monitor (NALM) is de- signed to monitor an electrical circuit that contains a number of devices (appliances) which switch on and off independently [1]-[20]. By a sophisticated analysis of the current and voltage waveforms of the total load, the NALM estimates the number and nature of the individual loads, their individual energy consumption, and other relevant statistics such as time-of-day variations. No access to the individual components is necessary for installing sensors or making measurements. This can provide a very convenient and effective method of gathering load data compared with traditional means of placing sensors on each of the individual components of the load. The resulting end-use load data is extremely valuable to consumers, utilities, public policy makers, and appliance manufacturers, for a broad range of purposes.