GB2376125A

GB2376125A - A utility prepayment system

Info

Publication number: GB2376125A
Application number: GB0113328A
Authority: GB
Inventors: Francesco Ricci
Original assignee: Siemens Metering Ltd
Current assignee: Siemens Metering Ltd
Priority date: 2001-06-01
Filing date: 2001-06-01
Publication date: 2002-12-04
Anticipated expiration: 2021-06-01
Also published as: GB0113328D0; GB2376125B; WO2002099759A3; AU2002319197A1; WO2002099759A2

Abstract

A utility prepayment system comprises a central processing unit (CPU) 7 operatively associated with a plurality of suppliers A, B, C for one or commodities, one or more remote commodity management units (RCMU) 2 operatively connectable to one or more commodity meters 4, 5, 6 to receive an indication of a commodity flow of a respective commodity, means to enable a commodity flow of a respective commodity and storage means 11 to store an indication of an amount of commodity allowance units (CAU), wherein the CPU 7 is operable to provide commodity allowance units purchased in exchange for a monetary value, wherein the amount of said commodity allowance units provided is dependent upon one or more variable commodity ratios, each commodity ratio being related to a specified amount of commodity allowance units per unit of commodity, and wherein said means to enable commodity flow are operable to allow an amount of one or more variable commodities to flow relative to said stored indication of said amount of commodity allowance units. The CPU 7 may be part of a customer management unit (CMU) 1. In an alternative embodiment the invention comprises a method for enabling an amount of commodity units to flow. In another alternative embodiment the invention comprises a method for purchasing an amount of one or more utility commodities in exchange of an amount of monetary value.

Description

IMPROVEMENTS IN OR RELATING TO A UTILITY PRE PAYMENT SYSTEMS Field of the Invention The present invention relates to a utility prepayment system and a method for purchasing an amount of one or more utility commodities. More specifically the present invention discloses a prepayment system and method for purchasing of one or more commodities in which an amount of commodity allowance is paid for in advance.

Background to the Invention Certain methods of prepaying for utilities exist in which a consumer purchases a monetary amount of gas or electricity. This is usually specified in pounds sterling or some other suitable currency such as Euros. The monetary amount of credit is stored on a consumer's smart card. When the card is placed into an appropriate slot associated with a consumer's gas or electricity meter, gas or electricity is allowed to flow up to the monetary value stored on the card. The charge rate for each unit of gas or electricity is set by the supplier and programmed into the gas or electricity meter.

The rate can vary depending on the market conditions. If the rate changes the supplier has to adapt the charge rate for each unit of gas or electricity in the respective gas or electricity meter. This results in much effort being spent by the commodity supplier, especially if the charge rate changes on a day by day basis.

Further, if the consumer chooses a prepayment method to purchase a plurality of commodities he has to check on the different commodity meters to realise in a timely fashion, whether the respective commodity allowance units for any of the commodities are running low. Then he has to purchase

new commodity allowance units to recharge the respective commodity meter.

Object to the invention It is therefore an object of the present invention to provide a utility prepayment system, which allows the consumer to purchase one or more commodities according to an associated supplier tariff given by a supplier.

Statement of the Invention According to one aspect of the present invention there is provided a utility prepayment system comprising a central processing unit (CPU) in operable association with a plurality of suppliers for one or more commodities. A remote commodity management unit (RCMU) or consumer unit is in operable connection with one or more commodity meters to receive an indication of a commodity flow of a respective commodity. The RCMU includes means to enable a commodity flow of said one or more commodities and storage means to store an indication of an amount of commodity allowance units (CAU). The CPU is operable to provide commodity allowance units relating to an amount of commodity in exchange for a monetary value. The amount of said commodity allowance units provided depends on one or more variable commodity ratios associated with one commodity, wherein said one or more commodity ratios are determined by a specified amount of commodity allowance units consumed per unit of commodity. The means to enable commodity flow is operable to allow an amount of commodity to flow relative to said stored amount of commodity allowance units.

An advantage of the present invention is that the prepayment system can be substantially independent of the value of the monetary and/or energy units in which the commodity consumption is measured. By providing commodity allowance units and commodity ratios the prepayment system can be easily adapted to changes in tariffs, measurement units of the respective commodity and number of commodities to be supplied by the prepayment system. For example, changes in supplier tariffs can be accommodated by adapting the commodity ratio or the amount of commodity allowance units. Supplier tariff changes in a prepayment system where the commodity allowance units are used for more than one commodity can be accommodated by a recalculation of the commodity ratios and the commodity allowance units.

The remote commodity management unit can be located close to the place where the commodity is used and is preferably associated with a specific consumer or household wherein the used commodities are commonly paid for.

The storage means can be operable to store at least one commodity ratio, so that the commodity ratios can be changed during operation of the prepayment system.

The system can be operable to enable the flow of two or more commodities wherein the respective commodity ratio is related to the respective commodity. Thus each of the selected commodities can have at least one commodity ratio associated therewith wherein the at least one commodity ratio determines the amount of commodity allowance units relative to each unit of the respective commodity, e. g. m3, kWh etc.

The system may also further comprise receiving means which can be operatively connected to said CPU to receive commodity allowance units

remaining. aid storage means. The receiving means allows the CPU to be connected to e. g. a remote commodity management unit to receive data indicating the remaining commodity allowance units for a calculation of new commodity ratios and new commodity allowance units.

Upon the purchase of further commodity allowance units, the newly purchased commodity allowance units may be added to the commodity allowance units already purchased provided that no item of the supplier tariff data has changed. If one or more items of supplier tariff data have changed, then the commodity allowance units have to be recalculated by taking into account the commodity ratios which have been used for the calculation of the commodity allowance units remaining in the system. The system then calculates new commodity ratios associated with a new total of commodity allowance units including the commodity allowance units remaining and the newly purchased commodity allowance units which were purchased at a different supplier tariff.

The RCMU may include means for indicating the amount of commodity allowance units remaining in said storage means, so that the consumer gets an indication of how long or of what amount he is able to be supplied with commodities without purchasing further commodity allowance units. Preferably, requesting means are included which are operable to request a transmission of commodity allowance units to the CPU after the consumer has purchased the commodity allowance units. This allows the consumer to have full control of the purchase of commodity allowance units, for example, this enables the consumer to determine at what time commodity allowance units are being transferred to the RCMUs.

It may be preferred that the requesting means are operable only if said storage means indicate that the amount of commodity allowance units is

below a given amount. This could prevent large pre-emptive purchases of commodity allowance units prior to a publicised increase in commodity unit prices. Such a limit may be applied for a limited term after the announcement of the publicised increase until the increase has been made.

According to another aspect of the present invention there is provided a method for enabling an amount of commodity units to flow. This method can conveniently be carried out at the place where the commodities are consumed. To give the consumer a commodity allowance an amount of commodity allowance units is received from a commodity meter and an indication thereof is stored. An indication of a commodity flow of a

ive commod i h * ch's related respective commodity is received from a commodity meter, which is related to the flow of a specific unit of a respective commodity and which may relate to a specific period of consumption. An amount of commodity is allowed to flow wherein the amount of commodity is determined by the amount of commodity allowance units stored which is reduced by an amount given by at least one commodity ratio each time the respective commodity flow is indicated, whereby the commodity is consumed until there are no commodity allowance units remaining.

The method relates to the use of the commodity allowance units, for example in the respective remote commodity management unit, wherein an amount of commodity is allowed to flow, which amount is determined by the commodity ratio for a specified commodity and the amount of commodity allowance units stored e. g. in the RCMU.

In the instance where a consumer is supplied with different commodities the commodity ratios can become important. Depending on e. g. country specific units of measurement for money and/or for commodities, as different commodities are usually measured in different quantities or units

respectively e. g. kWh, m3 etc., the respective c Tiodity ratio gives a clear indication how many of the commodity allowaie units the spending of one unit of the respective commodity costs.

An advantage of this method is that it is able to be adapted for different measuring systems and/or different measuring accuracy, e. g. cubic feet, cubic meters etc. The adaptation to the different measuring units and/or different measuring accuracies can be easily done by just changing the respective commodity ratio. The same applies for the use of this system in different countries with different monetary currencies.

According to another aspect of the present invention the purchasing of an amount of one or more commodities in exchange of a monetary value is provided. A customer chooses a monetary value for which commodity is to be purchased. He selects a supplier tariff which is associated to a specific commodity provider and/or a specific commodity. An amount of commodity allowance units is calculated taking into account the selected monetary value, the supplier tariff and said commodity ratio, wherein the purchased commodity allowance units and said commodity ratio define the amount of commodity to be consumed according to the price per unit of commodity given in the supplier tariff. When a new amount of commodity allowance units are purchased, revised commodity ratios are calculated, taking into account the amount of commodity allowance units remaining and one or more previous commodity ratios.

Whilst a consumer may not wish to be concerned with actual commodity allowance units, the capability of purchasing in a"one-stopshop", commodity allowance units for a given monetary amount useable for all commodities may be attractive. Further the ability to purchase the same commodity from a number of suppliers of such a commodity enables

competitive prices to be realised in the market. It may be that a particular multi-commodity supplier may provide preferential tariffs if multicommodity purchases are made with respect to that multi commodity supplier by a consumer.

Brief description of the figures The invention will now be described, by way of example only, with reference to the Figure as shown on the accompanying drawing sheet.

Detailed description of the invention There will now be described, by way of example, the best mode contemplated by the inventors for carrying out the invention. In the following description, numerous specific details are set out in order to provide a complete understanding of the present invention. It will be apparent, however, to those skilled in the art, that the present invention may be put into practice with variations of the specific.

The Figure shows a block diagram of commodity prepayment system, which allows a consumer to purchase a commodity allowance from different suppliers and with different tariffs. By means of the prepayment system according to the invention the consumer can purchase commodity allowance units which represent a determined amount of one or more commodities.

The commodity prepayment system comprises a customer management unit (CMU) 1, which is connected to a number of remote commodity management units (RCMU) 2 although only one is shown for clarity. Each RCMU 2 is assigned to a specified consumer and placed close to a location where the specified consumer uses/meters his commodity. The

CMU 1 includes a data interface 8 which envies a connection to one or more assigned RCMU's 2 via a data link 3, respectively. The data link 3 may be a dial-up telephone line; it can be wireless or even hardwired. It is also possible to provide the data link 3 by means of a internet connection.

The data interface 8 can be a modem for allowing a dial-up of the assigned RCMU 2, a network interface and the like, to establish a data connection.

The RCMU 2 is connected to a plurality of metering units 4, 5, 6, for example an electricity meter 4, a gas meter 5 and a water meter 6, via respective signal connections C4, C5, C6. The metering units 4,5, 6 are operable to measure the flow of the respective commodity, for example, by transferring an electrical pulse output from the respective metering unit 4,5, 6 to the RCMU 2 via the respective signal connection C4, C5, C6. For example, the gas meter 5 may be operable to send out an electrical pulse every time an amount of 1/100 mu gas has flowed through the gas meter 5, as are known. Similarly, the electricity meter 4 may be adapted to send out an electrical impulse every time an amount of 0.1 kWh electricity which has been supplied to the consumer, the water meter 6 may be adapted to send out an electrical pulse every time an amount of 1 litre of water has flowed through the water meter 6. As it may be convenient for a respective pulse to be generated for other amounts of commodities.

The CMU 1 further includes storage means 11, which are able to store user account data, including personal data, purchased commodity allowance unit data, supplier data, etc. The storage means may comprise integrated circuit memory means. The CMU 1 includes a central processing unit (CPU) 7 which is able to perform calculations, including calculations relating to the purchase of commodity allowance units for money or moneysworth.

Furthermore, the CPU 7 can control several database management processes which are necessary to operate a user account.

Different commodity suppliers are associated to the CMU 1 for the same or different commodities herein referred to as supplier A, supplier B and supplier C. The suppliers A, B, C provide tariff data which include an indication about a price in monetary units per a determined unit of commodity. The tariff data can be dependent on daytime and/or amount of commodity spent or purchased, respectively, or other. For example, the tariff data can provide that the price for the commodity'electricity'in the morning or evening hours is higher than during the night-time. Alternatively it may be provided that the price for one commodity is reduced as a function of the amount of commodity already spent.

There is further provided a user data interface 9 which allows an authorised user, who can be a consumer of commodities, to log into the CMU 1 via a user terminal 10 which can be e. g. a personal computer. The authorised user at the user terminal 10 can then interact with the CMU 1.

Using the CMU 1 a purchase of one or more commodity allowance units can be performed by transferring e. g. a credit card number, authorisation codes, if appropriate, and the amount of money for which commodity allowance units are to be purchased. It is also possible to use other known ways of purchasing if the CMU 1 receives information about the amount of money for which commodity allowance units are to be purchased. If the consumer account does not provide information about the selected supplier for each commodity the consumer is requested to select a

s specific supplier via the assigned user terminal 10.

A purchase request for commodity allowance units by the consumer is processed by the CMU 1. Given appropriate input means, the customer is

requested to enter a monetary value for which he is willing to purchase commodity allowance units. If not already stored with reference to his personal data in the storage means 11 the consumer is requested to enter assigned suppliers or selected tariff data, respectively, for each of the commodities he wants to have supplied by the CMU 1. If preferred suppliers have already been selected, identified and stored in the storage means 11 the consumer can be asked if he wants to change one or more of the suppliers or tariff data, respectively, or not.

The purchase of commodity allowance units according to the invention is performed in the CMU 1. A consumer accesses the CMU 1 either directly via an terminal integrated in the CMU 1 or via the user terminal 1 0 connected via the user data interface 9, respectively. The consumer gains access to use the CMU 1 by identifying himself in respect of

the personal data stored in the storage means 11 of the CMU 1.

In the storage means 11 of the CMU 1, customer specific data is stored e. g. as a customer account. The customer account may include personal data, data indicating newly purchased customer allowance, previously selected supplier, etc.

Once logged in the CMU 1, the customer will be requested to enter a monetary value for which commodity is to be purchased. If the personal account assigned to the authorised consumer already includes selected tariff data for the wanted commodities, the consumer may be requested if he wants to select tariff data associated with a different supplier. If no tariff data has previously been selected then the customer will be requested to enter one or more suppliers for each of the commodities he wants to be supplied with. To every selected supplier, there is at least one set of tariff data wherein the

price for the respective commodity, i. e. the price per defined unit of commodity, is fixed.

The tariff data may contain different prices for the same commodity depending on e. g. the time of consumption or depending on the amount of the respective commodity which has been spent. An indication of the selected monetary value for commodity allowance units to be purchased and the tariff data for every selected supplier is stored in the respective storage means 11 of the CMU 1. It may also be possible to store data indicating commodity allowance units and respective commodity ratios for each selected commodity. The respective data is stored in the CMU 1 as newly purchased commodity allowance units which is stored to be transferred to the RCMU 2 assigned to the respective consumer.

In the event that, for example, a consumer notices that there is only a small amount ofCAU's remaining he can request a transfer of the newly purchased CAU's and/or commodity ratios from the CMU 1. Conveniently this can be done by pressing a push-button 13 included in the RCMU 2.

After the request has been sent via the data link 3 to the CMU 1, the CMU 1 requests the RCMU 2 to send the remaining commodity allowance units to the CMU 1. The remaining commodity allowance units will be stored in the storage means 11 of the CMU 1.

The CPU 7 then determines a new amount of CAU's which is to be stored into the RCMU 2 replacing the previous amounts ofCAU's. The determination takes into account the CAU's in the storage means 12 of the RCMU 2, the amount of money for which new commodity is to be purchased and the selected tariff data for each selected supplier. A result of this calculation is an amount ofCAU's and one or more (depending on the tariff structure) commodity allowance ratios for each of the selected

commodities which are transferred via the data link 3 to the RCMU 2 where it is stored in the storage means 12.

This calculation can be easily performed if the commodity ratio is unchanged since the last purchase ofCAU's, i. e. the consumer has not changed the supplier and the supplier has not changed tariff data. In this case CAU's are calculated by taking into account the commodity ratios of the commodities that are being consumed, the price of each commodity and the selected monetary value according to the following:

where MV is monetary value, CRI is the commodity ratio of the first commodity, and

PU1 is the price per specified unit of the first commodity.

The newly calculated commodity units CAUnew are simply added to the CAUOLD previously remaining in the RCMU 2 and the sum CAUTOTAL is transferred back to the RCMU 2.

If the tariff data of one or more commodities has changed between the last purchase ofCAU's and a subsequent purchase ofCAU's, then not only do new CAU's have to be calculated but it is also preferred to calculate new commodity ratios for each of the commodities. In this case the commodity allowance units CAUo1d remaining are recalculated according to the following equations which show as an example case where two different commodities are supplied to a consumer:

. CA UOLD Amount of commodity 1 to be used according to CAUoLD --D CRI OLD Amount of commodity 2 to be used according to CAUoLD CL WOLD CR 2 OLD

where CR1NEW is new commodity ratio for commodity 1, CR2NEW is new commodity ratio for commodity 2, CRIOLD is old commodity ratio for commodity 1, CR2OLD is old commodity ratio for commodity 2, PU I is price per unit of commodity 1, PU2 is price per unit of commodity 2, and CAUold are the commodity allowance units remaining.

As can be seen in the first equation, the total amount of commodity allowance units CAUTotal which is to be transferred to the RCMU 2 and the

commodity ratio CR1NEW depend on one another by a factor given by the equation. Accordingly, the CAUtotal or the commodity ratio CR1NEW can be selected. To keep the RCMU 2 simple in design it is useful at this point to

select the CAUtotal and the CR1new and the CR2new in whole numbers so that the RCMU 2 is operable with a processing unit which is sufficient to perform integer operations. This enables the RCMU 2 to be simplified and thus to reduce the costs of producing such a unit. A possible way to determine the commodity ratios for each commodity is to carry out a least common denominator calculation of the commodity ratios.

The transfer of the total amount of the commodity allowance units CAUnew to the RCMU 2 overwrites the CAUo1d remaining in the RCMU 2.

In the period between the transfer of the commodity allowance units remaining CAUo1d from the RCMU 2 to the CMU 1 and the retransfer of the newly calculated commodity allowance units CAUTotal from the CMU 1 to the RCMU 2 the commodity allowance units CAUold already stored in the RCMU 2 have to remain unchanged. Therefore it is necessary to perform the calculation in real-time so that no commodity allowance units are spent in the RCMU 2 while the calculation is carried out in the CMU 1. If one or more of the metering units 4,5, 6 indicate that another unit of a commodity has been spent the indication has therefore to be buffered until the retransfer of the newly calculated commodity allowance units CAUTotal has been finished.

Commodity allowance units CAU as well as the commodity ratios Cari, CR2 are stored in the storage means 12 of the RCMU 2. The storage means 12 are kept small to reduce the production costs of the RCMU 2.

Further it is provided that more than one commodity ratio for one of the commodities being supplied is provided. This is to provide a more sophisticated concept of a supplier tariff, which allows to have more dedicated cost model of the respective commodity depending on the time of the day or the amount of the respective commodity being spent.

The RCMU 2 is connected to metering units 4,5, 6 responsible for measuring each of the commodities being supplied to the consumer. The metering units 4,5, 6 are operable to indicate every specified unit of commodity which has been metered through the respective meter, respectively. According to the respective commodity ratio associated with the respective commodity the amount of commodity allowance units CAU stored in the storage means 12 of the RCMU 2 is reduced by the value of the respective commodity ratio each time the metering unit indicates that an specific amount of units of commodity is being spent. The commodities are supplied as long as there are still enough commodity allowance units remaining in the storage means 12 of the RCMU 2. If there are no more commodity allowance units CAU remaining the supply of one or more of the commodities may be disabled.

One option that may be implemented in a system is the provision of a feature that will prevent the supply being cut off if there are no more commodity allowance units remaining. It is also possible to give the consumer an emergency commodity allowance which allows the consumer to use a credit amount of commodity allowance units in the RCMU 2. The emergency commodity allowance can be regarded on the one hand as a credit of commodity allowance units CAU or on the other hand as an allowance to consume a maximum amount of commodity allowance units per time unit to allow the consumer to be supplied with commodity for emergency purposes, such as supplying the fridge with electrical energy etc.

There may also be provided the option for guaranteed supply periods to maintain a minimum supply to the consumer.

In another preferred embodiment of the present invention the consumer could assign an account number (with direct debit capability) for

his RCMU 2. So when a request is made for a new commodity allowance, e. g. if the commodity allowance is below a certain predefined level, a predefined amount is deducted from the consumer's account and the commodity allowance is automatically updated by transferring newly purchased CAU's to the RCMU 2. For example, a consumer could set the direct debit amount to 10 Pounds which is transferred as if his allowance has fallen below 3 Pounds-worth of units.

The remote commodity management unit 2 can also include indicators indicating a commodity allowance level for reminding the consumer if there are sufficient commodity allowance units left. There may be also provided indicating means for to indicate if the supply of commodities is switched on or off. For example, these indicators can be LED's or other means for indicating. The RCMU could also be configured to automatically enable a certain amount ofCAU's to be purchased if the level ofCAU's stored in the RCMU (or CPU if the system is so configured) falls below a predetermined level. Direct debiting or similar methods of pre-authorised payment would be appropriate. The predetermined minimum level may vary as a function of reason.

The invention can also allow the provision of different rates for the same commodity, for example for different time periods of the day/different days of the week etc. This could be implemented by treating the different rates of the same commodity as different commodities, which would extend the calculations described above. This could assist in a consumer changing his usage habits.

As will be appreciated by those skilled in the art various modifications may be made to the embodiment herein before described without departing from the scope of the present invention.

Claims

Claims 1. A utility prepayment system comprising: a central processing unit (CPU) operatively associated with a plurality of suppliers for one or more commodities, one or more remote commodity management units (RCMU) operatively connectable to one or more commodity meters to receive an indication of a commodity flow of a respective commodity, means to enable a commodity flow of a respective commodity and storage means to store an indication of an amount of commodity allowance units (CAU), wherein the CPU is operable to provide commodity allowance units purchased in exchange for a monetary value, wherein the amount of said commodity allowance units provided is dependent upon one or more variable commodity ratios, each commodity ratio being related to a specified amount of commodity allowance units per unit of commodity, and wherein said means to enable commodity flow are operable to allow an amount of one or more variable commodities to flow relative to said stored indication of said amount of commodity allowance units.

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2. A system according to claim 1, wherein said storage means are operable to store at least one commodity ratio.

3. A system according to claim 2, wherein said commodity allowance units stored in said storage means are reduced by an amount dependant upon said respective commodity ratio and commodity usage.

4. A system according to one of the claims 1 to 3, wherein the system is operable to allow the flow of two or more commodities, wherein each of said respective commodity ratios is related to one of said two or more commodities.

5. A system according to one of the claims 1 to 4, wherein the system further comprises receiving means connected to said CPU to receive commodity allowance units stored in said storage means.

6. A system according to one of the claims 1 to 5, wherein said remote commodity management unit includes means for indicating the amount of commodity allowance units stored in said storage means.

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7. A system according to one of the claims 1 to 6, further including requesting means operable to request transmission of said commodity allowance units provided by said CPU.

8. A system according to one of the claims 1 to 7, wherein said requesting means are operable dependent upon whether said stored amount of commodity allowance units is below a given amount.

9. A remote commodity management unit operable in a utility prepayment system according to one of the claims 1 to 8.

10. A CPU operable in a utility prepayment system according to one of the claims 1 to 8.

11. A method for enabling an amount of commodity units to flow, with the steps of : receiving an amount of commodity allowance units; storing an indication of said amount of commodity allowance units, receiving an indication of a commodity flow of a respective commodity, reducing said stored indication of said commodity allowance units with an amount indicated by one or more commodity ratios associated with said respective commodity upon receipt of an indication that commodity flow has occurred,

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allowing a unit of commodity to'ow re is an indication of said commodity allowance units stored.

12. A method according to claim 11 wherein said commodity ratio is associated to a specific commodity tariff provided by a commodity supplier.

13. A method according to claim 11 or 12, comprising the further step of indicating the amount of said stored commodity allowance units so that it is indicated that the amount of commodity is running low.

14. A method according to claim 11 to 13, wherein the step of storing an indication of commodity allowance unit includes the adding of the amount of said commodity allowance units received to an amount of commodity allowance units presently stored.

15. A method according to one of the claims 11 to 14, including the further steps of : receiving said one or more commodity ratios; and storing an indication of said one or more commodity ratios.

16. A method according to claim 15, wherein said one or more commodity ratios are received with said commodity allowance units received.

17. A method according to one of the claims 11 to 16, wherein said one or more commodity ratios are each determining an amount of commodity

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allowance units by which the indication of said stored commodity allowance units are to be reduced by any indication of said commodity flow of said respective commodity. is. A method according to one of the claims 11 to 17, wherein said one or more commodity ratios are each associated to a specific commodity type.

19. A method according to one of the claims 11 to 18, with the further step of transmitting said amount of commodity allowance units presently stored to a central processing unit.

20. A method for purchasing an amount of one or more utility commodities in exchange of an amount of monetary value, said method including the steps of : selecting said monetary value for which commodity is to be purchased, selecting a supplier tariff associated to a specific commodity provider and/or a specific commodity, providing one or more commodity ratios, using the selected monetary value, said supplier tariff and said one or more commodity ratios, calculating an amount of commodity allowance units wherein said amount of commodity allowance units and said commodity ratio determine the amount of commodity to be consumed.

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21. A method according to claim 20, comprising the further steps of : transferring said amount of commodity allowance units.

22. A method according to claim 20 or 21, wherein the step of providing said one or more commodity ratios includes a least common denominator determination.

23. A method according to one of the claims 20 to 22 with the further step of receiving an amount of commodity allowance units remaining, wherein said step of calculating said amount of commodity allowance units includes that said commodity allowance units remaining are taken into account.

24. A method according to claim 23 wherein a plurality of supplier tariffs are provided each associated to a specific commodity type, wherein said one or more commodity ratios are calculated and each associated to said

if specific commodity type, wherein said amount of commodity allowance units and said one or more revised commodity ratios are calculated by using said amount of commodity allowance units remaining and said one or more previous commodity ratios.

25. A method according to claim 20 to 24 wherein said one or more commodity ratios are transferred to a RCMU.

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26. A method according to claim 20 to 25 wherein said one or more commodity ratios and said amount of commodity allowance units are transferred to said RCMU following a request signal transmitted by said RCMU.

27. A method according to one of the claims 20 to 26, wherein said supplier tariffs include condition data determined upon a time basis or consumption basis and ratio data, wherein the ratio data indicates an amount of commodity allowance units by which a total of commodity allowance units is to be reduced related to a consumed amount of one of said commodities or the time when said commodities are consumed.