GB2258052A

GB2258052A - Electricity consumption cost metering

Info

Publication number: GB2258052A
Application number: GB9215362A
Authority: GB
Inventors: Andrew Forrest
Original assignee: General Electric Co PLC
Current assignee: General Electric Co PLC
Priority date: 1991-07-24
Filing date: 1992-07-20
Publication date: 1993-01-27
Also published as: GB9115977D0; GB9215362D0

Abstract

An electricity consumption cost meter comprises means (1) for measuring the consumption of electric energy; means (7) which stores for each of a plurality of successive time periods the price of energy to be supplied by the meter; means (9) for multiplying the consumption of energy in each period and the price of energy for that period; means (11) for totalling the cost of energy consumed during the time periods; and means (17) which periodically updates the price data stored in the storage means. <IMAGE>

Description

Electricity Consumption Metering Apparatus and Methods This invention relates to electricity consumption metering apparatus and methods.

Conventionally electricity consumption meters record the total quantity of electric energy used and a bill is prepared by multiplying the total consumption as recorded by the meter for the billing period by the price of energy during that period. Where more than one price is operative, e.g. one for night time use of electricity and one for day time use, a separate register is used for recording energy use at each price.

Since privatisation of the electricity generating industry, all electricity generated in England and Wales is sold to a pool at a price set separately for each half-hour period. The forty-eight half-hour prices for each twenty-four period not being finally decided until during the preceding twenty-four period.

Whilst most electricity is bought from the pool by regional electricity companies for resale to consumers at a tariff set by the regional companies, some large consumers purchase electricity from the pool directly. In order to bill such large consumers using conventional energy consumption meters the meters are required to record separately the energy consumed in each half-hour period through the billing period, e.g. to record about 1,500 readings for each month. These readings then have to be used by the supply Authority to compute a bill for the period. This makes the metering equipment complex, requiring a large memory, and furthermore it is difficult for consumers to monitor their charges.

It is an object of the present invention to provide electricity consumption metering apparatus and methods whereby this problem is overcome.

According to a first aspect of the present invention there is provided an electricity consumption metering apparatus comprising: measuring means for measuring the consumption of electric energy: storage means which stores in respect of each of a plurality of successive portions of a predetermined time period the price of electric energy to be supplied to a load; means for obtaining the cost of energy consumed during a said portion by multiplying the consumption of energy in that portion measured by the measuring means and the price of energy for that portion stored in said storage means; register means for totalling the cost of energy consumed during said portions; and updating means which periodically updates the prices stored in said storage means with prices relating to a calendar period immediately following the calendar period to which the stored prices related prior to being updated.

In a preferred embodiment of the invention, the updating means updates said prices on a daily basis with prices relating to a twenty-four hour calendar period and said portion is a half-hour portion, in which case said storage means suitably stores from forty-eight to ninety-six prices.

Preferably said means for updating comprises: means for transmitting signals containing new price data required for updating and means for receiving said signals and entering said new price data in said storage means in place of price data no longer required. The transmitted signals may, for example, be radio signals, signals transmitted via a signal transmission line, e.g. a telephone line, or signals transmitted via an electric power transmission line which supplies electric energy to the load.

An apparatus according to the present invention may suitably also include further register means for totalling the electric energy consumed during said portions as measured by said measuring means. The further register means may include means for storing in respect of each of a number of said portions the electric energy consumed in that portion, as measured by said measuring means, if no price for that portion is stored in said storage means, so that the cost of the energy consumed during that period can be calculated later when the price becomes available.

According to a second aspect of the present invention there is provided a method of metering the consumption of electricity comprising: measuring the consumption of electric energy; storing in respect of each of a plurality of successive portions of predetermined time period the price of electric energy to be supplied to a load; obtaining the cost of energy consumed during a said portion by multiplying the consumption of energy measured for that portion and the price of energy stored for that portion; totalling the cost of energy consumed during said portions; and periodically updating the prices stored with prices relating to a calender period immediately following the calendar period to which the stored prices related prior to being updated.

In a preferred method according to the invention the updating is carried out on a daily basis with prices relating to a twenty-four hour calendar period and said portion is a half-hour portion, in which case from forty-eight to ninety-six prices are suitably stored at any one time.

The updating is suitably effected by transmitting signals containing new price data required for updating to a receiver which stores said new price data in place of price data no longer required. The transmitted signals may, for example, be radio signals, signal transmitted via a signal transmission line, e.g. a telephone line, or signals transmitted via an electric power transmission line which supplies electric energy to the load.

One electricity consumption metering apparatus and method in accordance with the invention will now be described, by way of example, with reference to the accompanying drawing which is a block schematic diagram of the apparatus.

Referring to the drawing the apparatus includes a meter located at a consumer's premises including measuring means 1 of known form for measuring in kilowatt-hours the amount of electric energy consumed in a load 3 connected to a supply of electric energy (not shown) via an electric power supply line 5.

The meter further includes a storage means 7 wherein data is stored in electronic form defining the price per kilowatt-hour of electric energy supplied to the load 3 for each of a plurality of successive future half-hour time periods.

The meter further includes multiplying means 9 wherein, at the end of each half-hour period for which a price is stored in the storage means 7, the price for that period is multiplied by the kilowatt-hours consumed in the load 3 during that period. The resulting cost figure obtained is passed to a summing 11 register which thus keeps a running total of the cost of energy consumed in the load 3. The total cost stored in the register 11 is displayed by a display means 13.

The half-hour period energy consumption measurements made by the measuring means 1 are also passed to an energy register means 15 arranged to keep a running total of the energy consumed. The energy register means 15 may be arranged also to store the total energy consumed in each twenty-four hour period. This enables an estimate of the cost of electricity consumed to be made for periods for which, for any reason, no price is stored in the storage means 7.

Alternatively, the energy register means 15 may be arranged to store, for each of a number of half-hour periods, e.g.

forty-eight half-hour periods, the energy consumed in the load 3 if no price for that half-hour period is stored in the storage means 7.

The cost for that period can then be calculated later when the price becomes available.

The prices stored in the storage means 7 are periodically automatically updated. To this end the apparatus further includes a transmitter (not shown) which periodically transmits signals containing price data. These transmitted signals are received by a price data receiver 17 in the consumer's meter and the new price data they contain is written into locations in the storage means 7 where price data no longer required is stored. Typically the receiver 17 receives price data from the transmitter on a regular basis for calendar periods of a predetermined duration, e.g. for each twenty-four hour calendar period on a daily basis.In such a case the storage means 7 must be capable of storing at least forty-eight prices and, if the price data is to be received before the end of the last half-hour period of the preceding twenty-four hour calendar period, must be capable of storing more than forty-eight prices, typically ninety-six prices so that the storage means contains prices for a forty-eight hour period at a time.

The price data received in respect of an immediately following twenty-four hour calendar period may be only a forecast of prices. Confirmed price data may be transmitted to the meter and used to correct cost data only subsequently, e.g. twenty-eight days later. The confirmed price data may be in the form of a correction factor for a twenty-four hour calendar period.

The signal transmitted by the transmitter is suitably a radio signal received by an antenna 19 connected to the receiver 17.

The price data is suitably in the form of phase modulations of the carrier wave of an amplitude modulation radio broadcast signal.

Such a system is already used in the electricity supply industry under the name the National Radio Teleswitch network for transmitting time information to keep clocks in multi-tariff electricity consumption meters in synchronism with a master clock, and transmitting tariff data. It will be appreciated that such a system of clock synchronisation may also usefully be employed in apparatus according to the present invention to ensure accurate apparatus according to the present invention to ensure accurate timing of cost calculations. The radio signals may alternatively be radio telephone signals, or coded signals transmitted as modulation of the carrier wave of a television broadcast signal between fields of the television signal i.e. a teletext signal.

Instead of transmitting price data to the receiver 17 as radio signals, it may be transmitted via a conventional transmission line e.g. a telephone line. Alternatively price data signals may be transmitted via the power supply line 5 using a so-called mains signalling system.

It will be appreciated that the cost total in the register 11 will be periodically recorded, i.e. for billing purposes and/or verification of stored data by a customer and/or the supply authority, and the register may, if desired, be at the same time resets To this end the register 11 is suitably provided with a data port 21 to which may be connected portable data read-out equipment, a printer or a line connecting the register 11 to a computer operated by the supply authority.

Claims

1. An electricity consumption metering apparatus comprising: measuring means for measuring the consumption of electric energy: storage means which stores in respect of each of a plurality of successive portions of a predetermined time period the price of electric energy to be supplied to a load; means for obtaining the cost of energy consumed during a said portion by multiplying the consumption of energy in that portion measured by the measuring means and the price of energy for that portion stored in said storage means; register means for totalling the cost of energy consumed during said portions; and updating means which periodically updates the prices stored in said storage means with prices relating to a calendar period immediately following the calendar period to which the stored prices related prior to being updated.

2. An apparatus according to Claim 1 wherein said updating means updates said stored prices on a regular basis with prices relating to a calendar period of a predetermined duration.

3. An apparatus according to Claim 2 wherein said updating means updates said prices on a daily basis with prices relating to twenty-four hour calendar period.

4. An apparatus according to any preceding claim wherein said portions are half-hour portions.

5. An apparatus according to Claim 4 when dependent on Claim wherein said storage means stores from forty-eight to ninety-six prices.

6. An apparatus according to any one of the preceding claims wherein said updating means comprises: means for transmitting signals containing new price data required for updating and means for receiving said signals and entering said new price data in said storage means in place of price data no longer required.

7. An apparatus according to Claim 6 wherein the transmitted signals are radio signals.

8. An apparatus according to Claim 6 wherein the transmitted signals are signals transmitted via a signal transmission line.

9. An apparatus according to Claim 6 wherein the transmitted signals are signals transmitted via an electric power transmission line which supplies electric energy to the load.

10. A meter according to any one of the preceding claims wherein said updating means transmits confirmed price data and utilises said confirmed price data to correct the cost totalled in said register means.

11. An apparatus according to any one of the preceding claims including further register means for totalling the electric energy consumed during said portions as measured by said measuring means.

12. An apparatus according to Claim 11 wherein said further register means includes means for storing in respect of each of a number of said portions the electric energy consumed in that portion, as measured by said measuring means, if no price for that portion is stored in said storage means, so that the cost of the energy consumed during that period can be calculated later when the price becomes available.

13. An electricity consumption metering apparatus substantially as hereinbefore described with reference to the accompanying drawing.

14. A method of metering the consumption of electricity comprising: measuring the consumption of electric energy; storing in respect of each of a plurality of successive portions of predetermined time period the price of electric energy to be supplied to a load; obtaining the cost of energy consumed during a said portion by multiplying the consumption of energy measured for that portion and the price of energy stored for that portion; totalling the cost of energy consumed during said portions; and periodically updating the prices stored with prices relating to a calendar period immediately following the calendar period to which the stored prices related prior to being updated.

15. A method according to Claim 14 wherein the updating is carried out on a regular basis with prices relating to a calendar period of a predetermined duration.

16. A method according to Claim 15 wherein the updating is carried out on a daily basis with prices relating to a twenty-four hour calendar period.

17. A method according to any one of Claims 14 to 16 wherein said portions are half-hour portions.

18. A method according to Claim 17 when dependent on Claim 16 wherein from forty-eight to ninety-six prices are stored at any one time.

19. A method according to any one of Claims 14 to 18 wherein said updating is effected by transmitting signals containing new price data required for updating to a receiver which stores said new price data in place of price data no longer required.

20. A method according to Claim 19 wherein the transmitted signals are radio signals.

21. A method according to Claim 19 wherein the transmitted signals are transmitted via a signal transmission line.

22. A method according to Claim 19 wherein the transmitted signals are signals transmitted via an electric power transmission line which supplies electric energy to the load.

23. A method according to any one of Claims 14 to 22 further including transmitting confirmed price data and utilising said confirmed price data to correct the totalled cost of energy consumed.

24. A method of metering the consumption of electricity substantially as hereinbefore described with reference to the accompanying drawing.