Appliance monitoring and control systems

1. A system to provide feedback to a user of an appliance for energy saving, the system comprising a processor and code disposed in memory for execution by the processor, the code configured, when executed, for:

monitoring an energy consumption of the appliance;

inferring a mode of use of the appliance from said power consumption wherein said inferred mode of use comprises one of: an inferred amount of water heated by said appliance, and a temperature to which water is heated by said appliance; and

providing feedback to said user responsive to said inferred mode of use to indicate how an amount of energy used by said appliance may be reduced.

2. A system as claimed in claim 1 , wherein said code for monitoring said power consumption is configured for identifying one or more periods of operation of said appliance from data representing aggregate power consumption of a plurality of devices including said appliance.

3. A system as claimed in claim 2 , comprising an energy sensor for monitoring mains electricity power consumption of said plurality of devices.

4. A system as claimed in claim 1 , comprising a plug-through power sensing device for monitoring said power consumption.

5. A system as claimed in claim 1 , wherein said feedback comprises one or both of an estimated energy saving and an estimated cost saving by reducing one or both of an amount of water use and a temperature to which water is heated by said appliance.

6. A method of providing feedback to a user of an appliance for energy saving, the method comprising:

monitoring an energy consumption of the appliance;

inferring a mode of use of the appliance from said power consumption, wherein said inferred mode of use comprises one of: an inferred amount of water heated by said appliance, and a temperature to which water is heated by said appliance; and

providing feedback to said user responsive to said inferred mode of use to indicate how an amount of energy used by said appliance may be reduced.

7. A method as claimed in claim 6 , wherein said feedback comprises one or both of an estimated energy saving and an estimated cost saving by reducing one or both of an amount of water use and a temperature to which water is heated by said appliance.

8. A method as claimed in claim 6 , wherein one or more elements of the method are performed by a microprocessor executing a computer program code.

9. A method of identifying the operation of a power consuming device from an aggregate power series, the method comprising:

receiving an aggregate power series, the aggregate power series comprising aggregate power consumption data for a plurality of power consuming devices;

filtering the aggregate power consumption data to separate the aggregate power consumption data into a fast component and a slow component;

measuring an average power of the fast component;

determining periods during which the measured average power is greater than a first threshold; and

comparing at least one of the determined periods with a model defining operational characteristics of a power consuming device to identify the operation of a power consuming device.

10. A method according to claim 9 , wherein filtering comprises using a wavelet filter.

11. A method according to claim 10 , wherein the wavelet filter is a Haar wavelet filter.

12. A method according to claim 9 , wherein measuring an average power comprises measuring a right-tail-10% trimmed root-mean-square of the fast component.

13. A method according to claim 9 , wherein the operational characteristics of the module comprise one or more of cycle duration, frequency of drum activity and power consumption.

14. A method according to claim 9 , wherein the method is further operable to calculate the power consumption of the power consuming device from the aggregate power series, the method further comprising:

calculating the power consumption using the determined periods during which the measured average power is greater than the threshold, and the measured average power during the determined periods.

15. A method according to claim 9 , wherein the method is further operable to detect a fault in the operation of the power consuming device from the aggregate power series, the method comprising:

comparing the measured average power and/or determined periods with a model of a known operation of the power consuming device to identify differences indicative of a fault in the operation of the power consuming device.

16. A method according to claim 9 , wherein the power consuming device comprises one or more of a washing machine, dishwasher, tumble drier, iron and electrical oven.

17. A system for identifying the operation of a power consuming device from an aggregate power series, the system comprising a processor and code in memory for execution by the processor, the code configured, when executed, to:

receive an aggregate power series, the aggregate power series comprising aggregate power consumption data for a plurality of power consuming devices;

filter the aggregate power consumption data to separate the aggregate power consumption data into a fast component and a slow component;

measure an average power of the fast component;

determine periods during which the measured average power is greater than a first threshold; and

compare at least one determined period with a model defining operational characteristics of a power consuming device to identify the operation of the power consuming device.