Configuration Guide for: Real Time Unaccounted for Energy Settlement / Date: 04/01/0906/1808/09
Settlements & Billing
BPM Configuration Guide: Real Time Unaccounted for Energy Settlement
CC 6474
Version 5.10
ÓCAISO, 2009 / Page 29 of 29Settlements & Billing / Version: 5.10
Configuration Guide for: Real Time Unaccounted for Energy Settlement / Date: 04/01/0906/1808/09
Table of Contents
1. Purpose of Document 3
2. Introduction 3
2.1 Background 3
2.2 Description 4
3. Charge Code Requirements 5
3.1 Business Rules 5
3.2 Predecessor Charge Codes 7
3.3 Successor Charge Codes 7
3.4 Inputs - External Systems 7
3.5 Inputs - Predecessor Charge Codes or Pre-calculations 12
3.6 CAISO Formula 17
3.7 Outputs 24
4. Charge Code Effective Date 29
1. Purpose of Document
The purpose of this document is to capture the requirements and design specification for a SaMC Charge Code in one document.
2. Introduction
2.1 Background
For each Settlement Interval, the CAISO determines Unaccounted-for-Energy (UFE) based on Meter Data and allocates the cost of the UFE to Scheduling Coordinators (SCs). The allocation is based on their metered CAISO Demand within each Utility Service Area of a Utility Distribution Company (UDC). UFE is the quantity of Energy that represents the difference between the net Energy delivered into a UDC Service Area and the total net-metered Demand (with respect to Generation) within the UDC Service Area, after accounting for the effects of Transmission Losses within the UDC Service Area. UDC losses are calculated through use of system network model and associated nodal pricing application that serve as the basis for the MRTU market software, as well as the reliable operation of the power grid within the CAISO Control Area.
Prior to MRTU the CAISO calculated Transmission Losses through the use of Generator Meter Multipliers (GMMs) and Transmission Meter Multipliers (TMMs). GMMs and TMMs were determined for and applied to each Generator or intertie schedule in the hour-ahead market, and were based on the physical point or location at which the Generator or intertie injected power into the CAISO Control Area. The calculated losses were then compiled on a UDC basis for allocation to Business Associates who scheduled load or export with the UDC. With the introduction of MRTU, the Full Network Model (FNM) of the CAISO Control Area in conjunction with market application software determines the transmission losses. The Transmission Losses are determined for each UDC and UFE-settled Metered Subsystem (MSS) in the CAISO Control Area.
The UFE calculation accounts for UDC Service Areas that encompass a MSS. A MSS is a geographically contiguous system or entity located within a single Service Area of a UDC. In general, a MSS entity has been operating as an electric utility for a number of years prior to the ISO Start-up Operations Date as a municipal utility, water district, irrigation district, State agency or Federal power administration that is subsumed with the CAISO Control Area. A MSS entity provides CAISO-certified revenue quality meters at each MSS interface point with the CAISO Controlled Grid. Additionally, in a MSS entity there are CAISO-certified revenue quality meters on all Generating Units or, in the case of resource aggregation, all resources and Participating Loads internal to the MSS. A MSS is allowed to have pre-designated individual units perform load following without incurring uninstructed Energy deviation charges and associated penalties due to the Load following, and has the option, once a year, to choose to settle Energy provided to the CAISO on either a gross Settlement or net Settlement basis.
If a MSS has selected the CAISO to perform UFE settlement for the MSS, a UFE Settlement Amount will be provided for the MSS entity. The UFE Settlement selection is available to the MSS, independent of the two MSS Energy Settlement options – net Settlement or gross Settlement. However, in the case where a MSS subsystem is embedded within another MSS subsystem, the CAISO will calculate a UFE amount only for the top-level MSS subsystem (MSS Aggregator) containing the MSS subsystem.
To settle UFE Energy the CAISO will determine the UFE price from various applicable nodal prices. For the Settlement of UFE Energy associated with a UDC Service Area, the UDC Service Area’s Load Aggregation Point (LAP) price will be employed in the UFE amount calculation. The UDC LAP price is a load-weighted average of the Locational Marginal Prices (LMPs) at all priced nodes within the UDC. The CAISO will provide a UFE Settlement Amount for both a MSS entity and the UDC Service Area that encompasses the MSS entity. Under MRTU market rules, net MSS Demand and net MSS Supply Energy of MSS entities that elect net Settlement will be settled at the MSS-specific Load Aggregation Point price (the “MSS-LAP” price) that will differ from the UDC Service Area LAP price. The MSS-LAP price is a load-weighted average of the Locational Marginal Prices (LMPs) at all price nodes within the MSS. For MSS entities settled under the gross Settlement option, UFE Energy will be settled at the LAP price of the UDC Service Area that encompasses the MSS.
2.2 Description
In line with CAISO tariff, the CAISO shall calculate and account for Imbalance Energy and UFE for each (10-minute) Settlement Interval. For each Settlement Interval the CAISO shall settle Imbalance Energy in the Real-Time Market for each resource within the CAISO Control Area and all System Resources Dispatched in Real-Time. Imbalance Energy consists of Instructed Imbalance Energy (IIE), Uninstructed Imbalance Energy (UIE) and the pre-dispatched Energy associated with HASP-established Intertie Schedules (i.e., intertie Energy pre-dispatched with the Hour Ahead Scheduling Process). Additionally, the CAISO shall settle UFE as part of the Real-Time Market Settlements. To the extent that the sum of the Settlement Amounts for IIE (CC 6470), HASP-predispatched Energy (CC 6051), UIE (CC 6475), and UFE (CC 6474) do not equate to 0, the CAISO will assess Charges or make Payments for the resulting differences to all Scheduling Coordinators based on a pro-rata share of their Metered Demand for the relevant Settlement Interval. The latter cost reconciliation shall be performed in a downstream charge code process, CC 6477 - RT Imbalance Energy Offset
The CC 6474 configuration (as stipulated in this document) provides for the calculation of UFE and its cost allocation to SCs. As stated in the CAISO Tariff, for each Settlement Interval, the CAISO will calculate UFE in the CAISO Control Area, and for each Utility Service Area for which the IOU or Local Public-Owned Electric Utility has requested separate UFE calculation and has met the requirements applicable to a CAISO Metered Entity. The UFE will be settled as Imbalance Energy at the applicable Settlement Interval Locational Marginal Price calculated for each Utility Service Area for which UFE is calculated separately. UFE – attributable to meter measurement errors, Load profile errors, Energy theft, and distribution loss deviations – will be allocated to each Scheduling Coordinator (SC) based on the ratio of the SC’s metered CAISO Demand within the relevant Utility Service Area for which UFE is calculated separately to (divided by) the total metered CAISO Demand within the relevant Utility Service Area.
3. Charge Code Requirements
3.1 Business Rules
Bus Req ID / Business Rule /1.0 / The Real Time Unaccounted for Energy Settlement (CC 6474) configuration shall apply to each Scheduling Coordinator who has metered CAISO Demand and Real-Time Interchange export schedules in either a Utility Service Area or MSS area for which the associated utility has requested separate UFE calculation and has met the requirements applicable to a CAISO Metered Entity.
2.0 / This Charge Code shall be computed daily on a 10-minute Settlement Interval basis.
3.0 / The Real Time Unaccounted for Energy Settlement (CC 6474) configuration shall both calculate UFE for a Utility Service Area and allocate its cost to SCs who have metered CAISO Demand and Real-Time Interchange export schedules from the Utility Service Area.
3.1 / A flag shall be used in the design to identify input data that pertains to a UDC/MSS for which the UFE calculations shall be performed (because the UDC/MSS has requested the CAISO to perform a UFE calculation for the UDC/MSS).
3.2 / The Measured Demand over Control Area configuration is expected to provide Metered Demand outputs for the UFE calculation that exempt Business Associates or combinations of Business Associates and resources from the UFE allocation and its associated UFE charge in accordance with transmission-related contracts. (Reference)
3.3 / The CC 6474 configuration shall calculate UFE as the difference of all generation (from Generators and Imports) and Demand (from Loads and Exports) adjusted for transmission losses.
3.4 / Meter data shall be provided for all Generation sources and Demand sinks, except in the case of import Energy or Export Energy where a meter device is not provided or is inadequate for determining UFE.
3.4.1 / For each intertie that connects a UDC or MSS to a CAISO-external Control Area, the CC 6474 configuration shall either receive an indication of whether or not UFE-applicable meter data exists.
3.4.1.1 / When meter data is available for an intertie, the CC 6474 UFE calculation shall reflect the meter data in its UFE determination as Energy entering (import) or leaving (export) the UDC or MSS through the associated intertie.
3.4.1.2 / When meter data is unavailable for an intertie, the CC 6474 UFE calculation shall employ Hourly Real-Time Interchange SchedulesChecked Out Intertie values to calculate the total quantity of Energy flowing through the intertie and apply the calculated value in the CC 6474 UFE determination as Energy entering (import) or leaving (export) the UDC or MSS through the associated intertie.
3.4.2 / For an intertie containing TG resources, the Metering subsystem shall provide a meter reading. Deleted
3.4.2.1 / The intertie meter reading shall include Energy for all System Resources (that are either importing or exporting Energy). Deleted
3.4.2.2 / The intertie meter reading shall exclude include Energy attributable to TG resources.
3.4.3 / For an intertie containing TG resources, the Metering subsystem shall provide the value of the deemed-delivered Energy quantity for each TG resource. Deleted
3.4.4 / The UFE calculation shall add the intertie meter reading that excludes TG resources to the deemed-delivered Energy quantity values of the intertie’s TG resources in order to determine the overall intertie meter reading that is required for the UFE calculation. Deleted
3.4.5 / The CC 6474 calculation shall receive transmission loss data that is considered to reflect “actual” transmission losses, as the loss data is determined from real-time market software based on actual power grid network conditions.
4.0 / UFE for a Utility Service Area shall be allocated to each SC based on the ratio of the SC’s metered CAISO Demand within the relevant Utility Service Area for which UFE is calculated separately to (divided by) the total metered CAISO Demand within the relevant Utility Service Area.
4.1 / Deleted.
4.2 / The allocated UFE settlement amount per SC per Utility Service Area is derived as the product of 3 components – the total Service Area UFE, the ratio of the SC’s share of the Service Area UFE to the total Service Area UFE, and the Service Area’s Locational Marginal Price (LMP).
5.0 / Actual SCs are referenced by Business Associate ID, and CAISO shall settle with Business Associates (BA) through these IDs.
6.0 / The formulas herein adopt the convention that payments made by CAISO to BAs will be negative, while payments received by the CAISO from BAs (charges to BAs) will be positive. (In other words, the signs reflect the flow of money from the point of view of the CAISO.)
3.2 Predecessor Charge Codes
Charge Code/ Pre-calc Name /Pre-calc - Real Time Price
Pre-calc – Measured Demand Over Control Area
Pre-calc – MSS Netting
3.3 Successor Charge Codes
Charge Code/ Pre-calc Name /CC 6477 – Real Time Imbalance Energy Offset
CC 6774 – Real Time Congestion Offset
3.4 Inputs - External Systems
Row # / Variable Name / Description /1. / RTED_Transmission_Loss uT’I’M’W’VL’mdhif / Real-time Transmission Loss quantity (in MW) (typically represented as a negative value) for UDC/MSS u of Entity Type T’ with MSS “Bubble” M’, MSS Gross/Net Energy Settlement Type I’, MSS Emissions Pay Flag W’, RUC Participation Flag V and Load Following Selection Flag L’, where the quantity applies to Dispatch Interval f of Settlement Interval i and Trading Hour h. The input value either equates to a value that the Market Quality Subsystem (MQS) provides as Real-Time Economic Dispatch (RTED) market data or equates to 0 (as provided by the Data Mapping process that overrides the MQS-provided value by forcing it to 0).
The data mapping process shall set the RTED_Transmission_LossuT’I’M’W’VL’hif input for Transmission Losses to 0 and override its associated MQS-provided loss value, for all u not in the set of UDC/MSS values that SaMC Standing Data explicitly stipulates for loss inclusion in the Real-Time UFE calculation. Currently Standing Data is expected to stipulate the inclusion of Transmission Losses for the UDC set {‘PGAE’, ‘SCE’, ‘SDGE’}. When u is in the set of UDC/MSS values (for instance, ‘PGAE’, ‘SCE’ and ‘SDGE’) for which Transmission Losses are expected to be included in the UFE calculation, the data mapping process shall not override the RTED_Transmission_LossuT’I’M’W’VL’hif input value received from MQS, passing the input unchanged to the UFE calculation.
The reason for setting the RTED_Transmission_LossuT’I’M’W’VL’hif input to 0 and overriding its associated MQS-provided value (to effectively exclude it from the UFE calculation), as described above, is that the UDC/MSS meter inputs for the associated Generation and Energy Imports (for which Transmission Losses normally apply) already include the overridden value.
1.1 / Mapped UDC/MSS Domain for
Input RTED_Transmission_Loss uT’I’M’W’VL’mdhif / If UDC/MSS Values are in {‘PGAE’, ‘SCE’, ‘SDGE’}:
1. For all values of u above, input RTED_Transmission_Lossuhif shall be mapped to the associated MQS-provided loss input
2. For all values of u not above, input RTED_Transmission_Lossuhif shall be forced to 0, regardless of the value of the associated MQS-provided loss input.