AU4372201A - Method and apparatus for settling a monetarised value of consumable product or service with actual product or service consumption - Google Patents

Description

u'IA/u- vx rn'i 1i;ju rAA 01 0 0400 101i1~iL~LA(J~(~i'iBL 0 kr-ttHILLb tANIM bRITH 13 LO 004 .1 I d P/0010O1 1 Raguator 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Method and apparatus for settling a monetarised value of consumable product or service with actual product or service consumption The following statement Is a full description of this invention, including the best method of performing it known to us; FruIis Carter Srrdt 59WO1MEL0601124017.6 04/05 '01 FRI 17:36 FAX 61 3 9288 1567FRELJSCRRSMT B FREEHILLS CARTER SMITH B 121005 2 METHOD AND APPARATUS FOR SETTLING A MONETARISED VALUE OF CONSUMABLE PRODUCT OR SERVICE WJTH ACTUAL PRODUCT OR SERVICE CONSUMPTION The present invention relates generally to a method and apparatus for settling a monetarised value of a consumable product or service over a computation period with actual product or service consumption. The present invention is suitable for use in the settlement of traded services provided by public utilities, such as electricity, gas and water, and it will be convenient to hereinafter describe the invention in relation to that exemplary, non limiting application.

For the purpose of trading electricity in environments where more than one entity supplies electricity to a distribution system, and more than one entity *consuming electricity is connected to the samne distribution system, and furthermore, where unit prices of energy or use of the distribution system vary with time, it is necessary to identify the amount of energy supplied by each supplier and withdrawn by each consumer within the time periods between price changes. In existing market structures, the time interval for matching consumption and supply with prices has typically been selected as whole hours or half hours, and is commonly referred to as the market interval.

A settlement process is typically invoked which requires that supply, consumption, and energy unit prices for particular market intervals are determined and the financial commercial contracts to supply, transport and use energy may be "settled" for each market interval.

The determination of the amount of energy passing through a point in a transmission or distribution network is usually obtained by the use of a Kilowatt hour energy meter. At large installations such metering arrangements also incorporate logging processes which produce a record of energy passing the point during each market interval. It is common to link large installations of this kind by radio or other direct communication means to one or more centralised data acquisition and processing facilities, which in turn provide the energy consumption data for the prescribed market intervals to interested parties.

RNM:DL 40272025 cap 4My20 4 May 2001 04/05 '01 FRI 17:36 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B Z~006 3 For consumers of energy with low consumption, such as small industrial plants or domestic supply Customers, it is unusual for the local metering equipment to include facilities for segregating consumption in market intervals. Meters in common Use typically provide a measure of accumulated energy from a long past installation date. These meters are read periodically so that the total energy consumed between two calendar dates is determined. The interval between these calendar dates, known as the reading interval, covers a large number of market intervals, these meters are not typically connected directly to a data acquisition process, but are more usually read manually, and in a large population are not all read concurrently i.e. the reading interval may be approximately uniform, but the start and finish date of the reading interval is cyclic with roughly equal numbers being read per reading day throughout the reading interval.

To allow a form of settlement to be achieved for such customers, a number of possible estimating processes have been developed. The term "deemed profile" 15 has been applied to a process whereby a class of consumers is considered to follow the same time of day patterns of energy use, and furthermore, a pattern typifying this usage can be determined. Each consumer in the class is then deemed to use electricity during market intervals according to this class profile, and the consumption is then estimated on the basis of allocating the known total 20 consumption for a meter reading interval to each market interval within the meter reading interval, so that the sum of energy allocated to each market individual is equal to the total for the meter reading period, and the relative amount of energy allocated conforms to the deemed profile. Various means of determining no tional profiles, processes of allocating consumers to sub-groups, and means of adjusting profile allocation are well known.

A particular shortcoming of simple profile estimation processes is the degradation of the cost reflectivity of the resultant settlement prices, compared to settlement prices that would have been established from actual marked interval consumption and actual energy unit prices during each demand interval. This difference is referred to hereinafter as a "settlement pricing error". This can be of minor importance if the price volatility from market interval to market interval is RNM-.DL 40272025 cap 4My20 4 May 2001 04/05 '01 FRI 17:37 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B [Q007 4 low, or if patterns of energy consumption at the consumer level are consistently close to a reference profile over a reasonable time period. However, where price volatility is high, and errors in reference profiles are present a settlement pricing error is likely to occur. Price of biasing will occur if errors in reference profiles are systematic, in the sense that a customer consumption profile, if determined over a significant number of days or weeks, is miaterially different in a sustained repetitive fashion i.e. follows a different "normal t usage pattern and these differences occur at times of day when prices tend to be higher or lower than average. This condition occurs where part of a load is under time-based switched control such as is embodied in some off-pea retail tariffs. The demand on the switched load is intentionally zero during normal high usage periods of the day or week. The load is connected only during times when general energy consumption is expected to be :low. These periods of load enablement are deliberately chosen to correlate to periods when energy generation and distribution marginal costs are relatively low.

:15 Hence the conditions for the existence of a settlement price bias are satisfied if electricity supply points include switched loads.

There also exists types of loads which by their nature are more likely to increase during peak usage periods, i.e. period of the day associated with higher than average marginal generation and distribution costs, and also above average unit 20 prices. these loads are not switched at defined times, and may not be objectively ****identifiable as being present at particular consumption points. Air-conditioning loads are one example of such a load.

*****Energy consumption by these loads may be relatively high as a proportion of the total load of a particular consumer during the period of use, and tend to occur at predictable times of the day. The likelihood of the load being connected at a particular time at an average location is, however, relatively low. Therefore, whereas the settlement pricing error for a particular location where such load exists, for a particular market interval or group of market intervals, can be relatively large, a settlement price bias is difficult or impractical to determine on the basis of consumption measured with a meter reading interval being a large number of marker intervals, for example, one month or three month reading intervals. This RNM:DL 40272025 cap 4My20 4 May 2001 04/05 '01 FRI 17:37 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B [Z008 conclusion remains generally valid even in the case of time-of-day metering where the metering interval is differentiated into high and low price times of the day.

Time-of-day metering therefore is of limited effectiveness in reducing or determining settlement price bias for such loads.

Time-of-day metering does provide means of measuring systematic biases, however, such as occur with loads switched to fixed or reasonably regular schedules, where such schedules involve switching load on during periods normally associated with low marginal cost of generation and distribution, and switching loads off again during other periods.

Some electricity services are provided as prne-payment or t pay-as-you-go" services, which typically involve a meter constructed to perform connection and disconnection of the service according to a process incorporated in the meter or apparatus cooperating with it. The process normally accepts a token or instruction that electricity service has been arranged and authorised for a designated period of 15 time, designated amount of consumption, or a designated value of energy or combination of the foregoing. The meter or cooperating apparatus accepts the token and thereafter acts according to the process and the quantity of services designated in the token so that when the service has been provided to the extent designated, the service is terminated by the apparatus. In this context, the token may be a coin or banknote, or data bearing means, such as a card bearing electromagnetic information.

One of the benefits of pay-as-you-go services is the elimination of the need for frequent service visits to customer premises, and a reduction in the need for routine meter reading. This benefit is desired by many consumers as a means of overcoming property access and privacy concerns. It also allows intermittent use of a service, so that premises which are used seasonally, for example, are only charged a service charge for the time the service is actually supplied. Pay-as-you-go processes remove the need for a service supplier to visit a site to execute connections and disconnections and record the meter reading and date recording associated with these activities.

Token issue or other prepayment records can be used to provide an estimate RNM;DL 40272025 cap 4My20 4 May 2001 04/05 '01 FRI 17:37 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B J9 6 of periodic electricity consumption. When the price of a consumer .energy service comprises a connection fee, a service fee and an energy consumption price which can be determined solely from knowledge of the amount of energy consumed during an interval of time, it is possible to establish an exact correspondence between the value of credit and the amount of energy consumed in KWhrs.

However, this process requires knowledge of the duration of the period over which the issued credit is consumed or a reasonable estimate of it. The errors and long term consumption matching problems associated with meter reading are substituted with uncertainty arising from matching credit issues with energy consumption.

Moreover, should a pay-as-you-go process employ the concept of time of day or time of use pricing, where the energy and distribution charges are varied with time, :the process of using credit issue credit consumption as a proxy for energy consumption becomes more difficult, because it is no longer possible to exactly map a total credit usage to a specific number of kilowatt hours, even if the periods 15 of energy and credit consumption are known and well matched.

There therefore exists a need to achieve accurate financial settlement between an energy producer and an energy user under circumstances where the energy price is variable under a time-of-day or time-of-use tariff, where the information available is restricted to a billing or credit issue history, tariff details and a deemed consumption reference profile.

There also exists a need to provide a method of more accurately achieving a financial settlement between an energy producer and an energy user where the energy price is variable under a time-of-day or time-of-use tariff, which overcomes or ameliorates one or more disadvantages of known financial settlement methods.

With this in mind, one aspect of the present invention provides a method for settling a prepaid monetarised value of consumable product or service over a computation period with actual product or service consumption, the price of the consumable product or service varying over time according to a retail time-of-use tariff profile, the method comprising the steps of: a) calculating from prepayment records a nett customer credit consumption for said computation period, RNM;DL 40272025 cap 4My20 4 May 2001 04/05 '01 FRI 17:38 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B [Q010 7 b) deriving a monetarised customer reference profile from a deemed customer consumption profile priced at said retail time-or-use tariff, c) allocating said net customer credit consumption to market intervals within said computation period in monetarised units according to said monetarised customer reference profile, d) transformning said monetarised units into actual product or service consumption in said market intervals by applying known retail prices for each said market interval.

In one embodiment of the invention, step includes: determining from said prepayment records a smoothed credit purchase profile, determining from said prepayment records an average credit purchase period, offsetting said smooth credit purchase profile by said average said credit 15 purchase period, and summing all credit purchases from said offset smooth credit purchase profile during said computation period.

The method may further include the step of: deducting any supplier service charges from said smooth credit purchase profile.

E. 0 20 The consumable product may consist of one or more commodities. The consumable service may consist of services provided by public utilities, such as electricity, gas or water supply.

Another aspect of the present invention provides an apparatus for settling a prepaid monetarised value of consumable product or service over a computation period with actual product or service consumption, the profile of the consumable product or service varying over time according to a retail time-of-use tariff profile, the apparatus comprising: credit issuing means for enabhing the prepayment of said consumable product or service over said computation period, data storage means for storing prepayment records, and processing means for calculating from prepayment records a net customer RNM:DL 40772025 cap 4My20 4 May 2001 04/05 '01 FRI 17:38 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B Qo]01 8 credit consumption for said computation period, deriving a monetarised customer reference profile from a customer consumption profile priced at said retail time-ofuse tariff allocating net customer credit consumption to market intervals within said computation period in monetarised units according to said monetarised reference profile, and transforming said monetarised units into actual product or service consumption in said market intervals by applying known retail prices for each said market interval.

The following description refers in more detail to the various features of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the method and apparatus are illustrated in a preferred embodiment. It is to be understood that the method and apparatus of the present invention is not limited to the preferred embodiment as illustrated in the drawings: V....Figure 1 is a schematic diagram illustrating an electrical energy distribution network and apparatus for settling a prepaid monetarised value of electrical energy over a computation period with actual electrical energy consumption according to one embodiment of the present invention; and Figures 2 and 3 are flow charts illustrating the method of operation of the apparatus shown in Figure 1.

Referring now to Figure 1, there is shown schematically an electrical energy distribution system 1 comprising an electrical energy supplier 2 to supplying electrical energy via a distribution network 3 to customers 4 and 5. Electricity meters 6 and 7 respectively interconnect consumers 4 and 5 to the electrical energy distribution network 3. The electricity meters 6 and 7 are of the type which require processing and acceptance of information borne on an electromagnetic infornation bearing card 8 or other "token". Such a meter enables the selective connection of a consumer to the electrical energy distribution network 3. The information borne by the card 8 normally contains an authorisation for electricity to be supplied for a designated period of time, a designated amount of consumption or a designated value of energy or combination of tw o or more of these. Once the quantity of service designated has been provided, the meter disconnects the consumer from the RNM:DL 40272025 cap 4My20 4 May 2001 04/05 '01 FRI 17:38 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B [a 012 9 electrical energy distribution network 3.

Depending upon the meter in question, the "token" may be a coin, flexible item of legal tender, or specially manufactured object incorporating its value or units of service, or a non-physical token in the form of a coded message. Coded messages may be transferred to the apparatus by telecommunications means, magnetically impressed messages, such as on cards, or as entries in memories on electronic devices and by direct keypad entry.

The creation and transfer of these "tokens" to consumers is traceable by means of a settlement apparatus 10 associated with the electricity supplier 2. The settlement apparatus 10 includes a processing means comprising a central processing unit 11I and associated program storage memory device 12, together with a data storage device 13 for the storage of temporary and permanent data required for the operation of the settlement apparatus 10. In addition, the settlement apparatus 10 includes a credit issuing device 14 for enabling the prepayment of 15 electrical energy supplied by the electricity supplier 2. In this example, such prepayment results in the production of the electromagnetic information bearing card 8.

The operation of the settlement apparatus 10 will now be explained with reference to Figures 2 and 3. In general, prepaymnents or customer credit transactions are recorded in the data storage device 13 in terms of their value, date of issue, meter identity and retail time-of-use profile. This credit issue data is subsequently used by the settlement apparatus 10 to perform the settlement of the prepaid monetarised value of electrical energy over a given computation period with the actual electrical energy consumed by a consumer.

Provided that the frequency at which credit purchase transactions occur is greater than the seasonal or averaging period characterised by seasonal factors affecting electricity usage, the total credit issue during a computational period which is required to be settled will be a forecast of total energy service usage charges for that computational period.

Accordingly, in step 20 of Figure 2, the net customer credit consumption for a given computation interval is calculated from prepaying records. One manner in RNM: DL 40272025 cap 4My20 4 May 2001 04/05 '01 FRI 17:39 FAX 61 3 9288 1587 FREEHILLS CARTER SMITH B IZ0c13 which this may be achieved is illustrated in Figure 3. Initially, at step 30, all customer credit consumption over a sample period is summed.

In step 31, the average credit consumption per day or other appropriate time period is then determined. At step 32, the average amount of electrical energy purchased by the consumer per transaction is determined.

At step 33, an estimate is computed from the results of steps 31 and 32 of the average number of days of electrical energy consumption purchased by the consumer at each transaction. At step 34, the prepayment records are recomputed as a smoothed function based on each purchase made and the number of days from the previous purchase, to produce a cur-rent "purchase value per day" profile.

Conventional smoothing processes may be applied to these values to produce a n..:smoothed, seasonal electrical energy purchase forecast.

:The smoothed forecast profile is then moved date-wise forward at step 35 by V-0 the number of days corresponding to the average pre-payment period, resulting in 00 @0 0 15 an estimated credit consumption for each consumer for specified periods where energy usage and credits consumption are more closely chronologically matched.

.*00.:At step 36, the consumer credit consumption profile is recalculated from the smoothed offset billing curve produced in step All fixed service charges are deducted at step 37, leaving only those portions the billing which are directly dependent upon the KWbxs purchased by the consumer. The result of step 37 is to produce a consumption or billing record per computation period directly attributable to the purchase of kilowatt hours of electrical energy.

Returning now to Figure 2, because the credits purchased by each consumer are monetarised or represented as standard kilowatt hours with a time-of-use weighting factor, a first approximation of the customer energy consumption profile is required. This is the standard deemed profile 40 stored in the data storage device 13. In addition, the stored retail time-of-usc tariff profile 41 is stored in the data storage device 13. At step 21 in Figure 2, the stored customer energy consumption profile is priced using the stored retail time-of-use tariff profile and re-standardised.

At step 22, the customer credit consumption as determined in step 20 is then RNM:DL 40272025 Cap 4My20 4 May 2001 04/05 '01 FRI 17:39 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B []014 11 allocated to market intervals in monetarised units for the relevant computation interval, in accordance with the monetarised reference profile determined in step 21.

The monetarised units are then transformed at step 23 into KWhrs 24 for the market intervals within the computation interval. In this step, known retail prices for each market interval are applied to produce a derived KWhI profile.

The above described computations can be compressed, however, maintaining the same logic, as follows: A retail-price-weighted demand conversion factor defined as follows is calculated.

Retail-Price-Weighted Demand Conversion Factor (CF) CF [1 0 Rt dt I() where t signifies a market (time) interval R R is the actual retail price (KWhr) rate, in currency effective at market interval t d is the reference profile ordinate for market interval t the factor which is applied to the total consumption for a metering interval (computation interval) to derive an estimate of the consumption occurring during t.

n is the number of market intervals occurring in the metering 20 interval.

~0 (CF is the reciprocal of the retail-priced reference profile. CF will be near constant or changing slowly according to irregular TOU days and systematic reference profile changes.) c $.CF.d (2) where c is the consumption in kilowatt hours allocated to this metering point at a market interval.

is the billing value (total of kilowatt hours dependent billing) during the metering (computation) interval for the consumer.

CF, d defined above.

The settlement data for the metering interval is therefore I $.CF I x [d 1 d 0 (3) RNM;DL 40272025 cap 4 May 2001 04/05 '01 FRI 17:39 FAX 61 3 9288 1567 FRELSCATRMIHB40i FREEHILLS CARTER SMITH B 0015 12 The term j effectively replaces the meter reading (consumption during the metering interval) in the interval consumption computation process.

The sum of c over the metering interval will not be identical to the true KWhr consumption total during the period, unless the true distribution of consumption between the retail price levels is identical to that which would occur when the consumer profile is identical to the reference profile (which implicity requires I $.CF Ito be equal to Xc.

I$.CF ]1 can be considered to be a TOU "distortion" factor.

The effect of distortion is a to re-scale the profile, to the degree that the actual user profile leads to a higher or lower financial settlement at wholesale, which in turn is the result of the actual usage being biased towards higher or lower pricing periods.

The net result is to increase or reduce the settlement cost to the retailer attributable to the customer.

The cost reflectivity linkage is qualitatively direct using energy at a higher cost period will increase the retail billing directly, and the wholesale settlement costs), through this mechanism.

It will be apparent from the foregoing that the present invention enables a settlement based on kilowatt hours consumption per market interval which requires no knowledge of actual market prices. A demand side management side process such as load switching, can be reflected in a consumer tariff in the absence of interval metering without introducing additional settlement process.

Moreover, cost reflectivity at settlement is provided in that consumers with repeating patterns of demand systematically varying from a reference profile are 25 able to be settled at prices higher or lower than the reference profile would indicate, and therefore may be billed at retail at correspondingly higher or lower retail prices without creating an inequitable disadvantage to an independent retailer.

Prepayment or energy retailing process incorporating time-of-use tariffs can be utilised to provide cost reflective settlements data, without the need for supplementary meter reading or the transfer of additional data from the meter to the credit issuing function.

RNM:DL 40272025 cap 4My20 4 May 2001 04/05 '01 FRI 17:40 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B QI016 13 Finally, it is to be understood that various modifications and/or additions may be made to the previously described mnethod or apparatus without departing from the spirit or amnbit of the present invention.

9* 9 9* 9- 9.

9 9 9 9. 9 999 9 9 999* RNM:DL 40272025 cap 4My20 4 May 2001

Claims (5)

1. 2. A method according to claims 2, wherein; step includes: determining from said prepayment records a smoothed credit purchase profile, determining from said prepayment records an average credit purchase period, offsetting said smooth credit purchase profile by said average said credit purchase period, and summring all credit purchases from said offset smooth credit purchase profile during said computation period.
2. 3. A method according to either one of claims 1 or 2, and further including the step of: deducting any supplier service charges from said smooth credit purchase profile. RNM:Dt. 40272025 cap4My21 4 May 2001 04/05 '01 FRI 17:40 FAX 61 3 9288 1567 FREEHILLS CARTER SMITH B [018
3. 4. A method according to any one of the preceding claims, wherein the consumable product consists of one or more comnmodities.
4. 5. A method according to any one of the preceding claims, wherein the consumable service consists of services provided by public utilities, such as electricity, gas or water supply.
5. 6. An apparatus for settling a prepaid monetarised value of consumable product or service over a computation period with actual product or service consumption, the profile of the consumable product or service varying over time according to a retail time-of-use tariff profile, the apparatus comprising: or edit issuing means for enabling the prepayment of said consumable product or ervceover said computation period, 15 data storage means for storing prepayment records, and processing means for calculating from prepayment records a net customer credit consumption for said computation period, deriving a monetarised customer reference profile from a customer consumption profile priced at said retail time-of- use tariff allocating net customer credit consumption to market intervals within said 20 computation period in monetarised units according to said monetarised reference profile, and transforming said inonetarised units into actual product or service consumption in said market intervals by applying known retail prices for each said market interval. DATED: 4 May 2001 FREEHJLLS CARTER SMITH BEADLE Patent Attorneys5 for the Applicant: NILSEN ]INDUSTRIAL ELECTRONICS PTY LTD RNM:DL 40272025 cap 4My20 4 May 2001