Abstract: A method of identifying the operation of an electrical appliance comprising an induction motor is described. The method comprises identifying the operation of an electrical appliance including an induction motor when a path traced by real power values against corresponding reactive power values over a time period of interest comprises one or more substantially circular arcs. The real power values are related to the total real power supplied to one or more electrical appliances as a function of time, and the reactive power values are related to the total reactive power supplied to the one or more electrical appliances as a function of time. There is also described a related method of identifying the operation of a specified type of appliance, in which the operation of said specified type of appliance is dependent on a supply of at least one utility such as electricity, natural gas or water.

Abstract: A non-intrusive method of determining, in respect of a group of appliances that are arranged to consume a utility, an indication of a background level of consumption of the utility by the group of appliances, the method comprising: receiving a series of utility values representative of a total level of consumption of the utility by the group of appliances; determining, based on the received utility values, an indication of a background level of consumption of the utility; and outputting the determined indication of the background level of consumption of the utility.

Abstract: A method of identifying the operation of an electrical appliance comprising an induction motor is described. The method comprises identifying the operation of an electrical appliance comprising an induction motor when a path traced by real power values against corresponding reactive power values over a time period of interest comprises one or more substantially circular arcs. The real power values are related to the total real power supplied to one or more electrical appliances as a function of time, and the reactive power values are related to the total reactive power supplied to the one or more electrical appliances as a function of time. There is also described a related method of identifying the operation of a specified type of appliance, in which the operation of said specified type of appliance is dependent on a supply of at least one utility such as electricity, natural gas or water.

Abstract: A method of outputting to a user an indication of the usage of a utility, the method comprising: obtaining data indicating, for each of a plurality of appliances, a respective current level of usage of the utility by that appliance; for each of a plurality of appliance categories, using the obtained data to calculate a respective current total level of usage of the utility by appliances belonging to that appliance category; and outputting an indication of the calculated current total level of usage of the utility for at least one of the plurality of appliance categories.