Household energy management system

• US 20050171645A1
• Filed: 11/26/2004
• Published: 08/04/2005
• Est. Priority Date: 11/27/2003
• Status: Active Grant

• Current Assignee: Centrica Hive Limited (Centrica PLC)
• Original Assignee: Wattbox Ltd. (Centrica PLC)
• Inventors: Tamsett, Stephen John, Oswald, James Ian
• Granted Patent: US 7,778,734 B2
• Time in Patent Office: Days
• US Class Current: 700/276
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 2219/2642 Domotique, domestic, home control, automation, smart house

Abstract

A household energy management system uses measurements of the household electricity supply 4 to identify and to determine the energy consumption of individual household appliances. From these measurements, models can be built of the behaviour of the occupants of the house, the thermal properties of the house and the efficiency of the appliances. Using the models, the household appliances—in particular heating and cooling appliances—can be controlled to optimize energy efficiency; and maintenance programmes for the appliances and for the house itself can be recommended to the householder or arranged with a service company.

Claims

1. A household energy management system, comprising:

at least one sensor, which measures energy use by occupants of the house;

a modelling means, which uses the energy measurements from the sensor to build a model of the behaviour of the occupants; and

a controller, which controls the operation of at least one household appliance in the house on the basis of the model.

2. A household energy management system according to claim 1, wherein the modelling means builds a predictive model of the pattern of behaviour of the occupants over time.

3. A household energy management system according to claim 2, wherein the modelling means continually refines the model in response to new measurements by the sensor.

4. A household energy management system according to claim 2, wherein the predictive model predicts the times when the house will be occupied and the controller controls the operation of at least one household appliance on the basis of the predicted times when the house will be occupied.

5. A household energy management system according to claim 4, wherein said at least one household appliance includes at least one heating or cooling appliance;

and wherein the controller controls the operation of said at least one heating or cooling appliance to achieve a desired temperature when the model predicts that the house will be occupied.

6. A household energy management system according to claim 5, wherein the controller controls the operation of said at least one heating or cooling appliance in such a way as to minimize the amount of energy used to achieve the desired temperature.

7. A household energy management system according to claim 1, wherein the modelling means builds a temporary model of the current behaviour of the occupants.

8. A household energy management system according to claim 7, wherein said at least one household appliance includes at least one heating or cooling appliance;

and wherein the controller controls the operation of said at least one heating or cooling appliance to achieve a desired temperature according to a current level of activity of the occupants as modelled in the temporary model of the current behaviour of the occupants.

9. A household energy management system according to claim 1, wherein the model of the behaviour of the occupants includes a determination of whether the house is occupied.

10. A household energy management system according to claim 9, wherein the modelling means has an interface for receiving signals from an intruder alarm system in the house and wherein the modelling means uses signals received from the intruder alarm system in its determination of whether the house is occupied.

11. A household energy management system according to claim 9, wherein the system receives signals indicating a location of the occupants when they are not in the house and wherein the modelling means uses the location signals in its determination of whether the house is occupied.

12. A household energy management system according to claim 11, wherein the modelling means further uses the location signals to predict the time when the occupants will return to the house.

13. A household energy management system according to claim 11, wherein the locations of the occupants are determined by a mobile telephone network.

14. A household energy management system according to claim 11, wherein the locations of the occupants are determined by a global positioning system.

15. A household energy management system according to claim 1, wherein the sensor measures electrical activity within the house.

16. A household energy management system according to claim 15, wherein said sensor comprises at least one moveable sensing device for location between an electricity supply outlet and an individual electrical appliance to measure the energy use by that appliance.

17. A household energy management system according to claim 15, wherein said sensor comprises at least one fixed sensor on an electricity supply to the household, which measures the respective energy uses of a plurality of electrical appliances connected to the supply, the fixed sensor comprising means for measuring the instantaneous total power delivered by the electricity supply and means for identifying the appliances on the basis of their respective start-up characteristics when the appliances are switched on.

18. A household energy management system, comprising:

at least one power sensor on the household electricity supply, which measures the instantaneous total power delivered by the electricity supply;

identification means for identifying electrical appliances connected to the supply on the basis of stan-up characteristics of the respective appliances sensed by the power sensor when the appliances are switched on;

comparison means for comparing the sensed start-up characteristics with reference start-up characteristics; and

warning means for warning a user of the system when the sensed start-up characteristics differ from the reference characteristics by more than a predetermined limit.

19. A household energy management system according to claim 18, wherein the comparison means further compares sensed operating characteristics of the appliances with corresponding reference operating characteristics.

20. A household energy management system according to claim 18, wherein the comparison means further compares sensed shut-down characteristics of the appliances with corresponding reference shut-down characteristics.

21. A household energy management system according to claim 18, further comprising means for recording the total time of operation of operation of each appliance.

22. A household energy management system according to claim 18, flier comprising means for recording the total number of cycles of operation of each appliance.

23. A household energy management system according to claim 21 or claim 22, including an interface for accessing a database of lifetime expectancy and reliability for different appliances, against which the logged data can be compared.

24. A household energy management system according to claim 23, wherein the interface for accessing the database provides access to a database on an external network;

and wherein the interface for accessing the database is also used to update the database with measured lifetime and reliability data for appliances connected to the system.

25. A household energy management system according to claim 23, further comprising modelling means, which receives signals from the comparison means and from the database in order to recommend to the user of the system a program of maintenance or replacement of the appliances connected to the system.

26. A household energy management system according to claim 18, further comprising means for recording the quality of the electricity supply measured by the sensor.

27. A household energy management system according to claim 18, further comprising:

at least one temperature sensor for measuring the temperature inside the house;

a source of information about the temperature outside the house;

a modelling means, which uses the inside temperature measurements received from the at least one temperature sensor and outside temperature measurements received from the source of information to derive a transient thermal model of the house, which model predicts changes in the inside temperature of the house on the basis of information about the current inside temperature, the current outside temperature and the operation of any heating or cooling electrical appliances that the identification means identifies as connected to the supply;

means for comparing the derived transient thermal model with a reference transient thermal model; and

warning means for generating a warning of poor thermal properties of the house or of poor efficiency of the connected heating or cooling electrical appliances when the derived model differs from the reference model by more than a predetermined limit.

28. A household energy management system according to claim 27, wherein the derived transient thermal model is periodically updated;

and wherein the reference transient thermal model is a derived transient thermal model from an earlier period, whereby the warnings are of deteriorating thermal properties of the house or of deteriorating efficiency of the connected heating or cooling electrical appliances.

29. An energy management network, comprising:

storage means storing a database of lifetime expectancy and reliability for different household appliances;

a plurality of household energy management systems, each comprising;

at least one power sensor on the electricity supply of a household, which measures the instantaneous total power delivered by the electricity supply;

identification means for identifying electrical appliances connected to the supply on the basis of start-up characteristics of the respective appliances sensed by the power sensor when the appliances are switched on;

comparison means for comparing the sensed start-up characteristics with reference start-up characteristics;

warning means for waning a user of the system when the sensed start-up characteristics differ from the reference characteristics by more than a predetermined limit; and

a network interface; and

a network to which the storage means and the plurality of household energy management systems are connected, the network enabling communication of data between the database and the household energy management systems.

30. A method of operating a household energy management system, comprising the steps of:

measuring energy use by occupants of a house;

using the energy measurements to build a model of the behaviour of the occupants; and

controlling the operation of at least one household appliance in the house on the basis of the model.

31. A method of operating a household energy management system, comprising the steps of:

measuring the instantaneous total power delivered by a household electricity supply;

identifying electrical appliances connected to the supply on the basis of start-up power characteristics of the respective appliances when the appliances are switched on;

comparing the sensed start-up characteristics with reference start-up characteristics; and

generating a warning when the sensed start-up characteristics differ from the reference start-up characteristics by more than a predetermined limit.