BILLINGIRAUCSURPLUSSUM
BILLINGIRAUCSURPLUSSUM contains Auction fees and Settlements Residue Auction distribution that may arise from unpurchased auction units that accrue to Transmission Network Service Providers.
BILLINGIRAUCSURPLUSSUM is confidential to the relevant participant.
Source
BILLINGIRAUCSURPLUSSUM is populated by the posting of a billing run where there are unpurchased auction units.
Volume
An indicative maximum is eight records inserted per billing run, or 88 records inserted per week.
Column Schema
BILLRUNNO
The sequential number of a billing run
SQL Type: NUMBER(3,0)
Polars Type: pl.UInt16
This column is mandatory, and a primary key.
CONTRACTYEAR
Contracted Year (calendar year)
SQL Type: NUMBER(4,0)
Polars Type: pl.UInt16
This column is mandatory, and a primary key.
FROMREGIONID
Nominated source region for Interconnector
For more information, see the dedicated documentation page.
The SQL type is VARCHAR2(10).
This is actually a factor/enum, with values:
-
QLD1 -
VIC1 -
TAS1 -
NSW1 -
SA1
This column is mandatory, and a primary key.
INTERCONNECTORID
Contracted Interconnector
SQL Type: VARCHAR2(10)
Polars Type: pl.Categorical
This column is mandatory, and a primary key.
PARTICIPANTID
Unique participant identifier
For more information, see the dedicated documentation page.
SQL Type: VARCHAR2(10)
Polars Type: pl.Categorical
This column is mandatory, and a primary key.
QUARTER
Residue Contract Quarter
SQL Type: NUMBER(2,0)
Polars Type: pl.Int8
This column is mandatory, and a primary key.
RESIDUEYEAR
Year of the Residue Contract; may differ from the calendar year at week 1.
SQL Type: NUMBER(4,0)
Polars Type: pl.Int16
This column is mandatory, and a primary key.
WEEKNO
Week no within the contract year. Week no 1 is the week containing 1st January
Warning
There may be 53 weeks in a year, depending on how weeks align to the year start/end.
SQL Type: NUMBER(3,0)
Polars Type: pl.UInt16
This column is mandatory, and a primary key.
ACTUALPAYMENT
Net payment to participant, including auction fees
SQL Type: NUMBER(15,5)
Polars Type: pl.Float64
This column is not mandatory.
AUCTIONFEES
Total auction fees payable in this week (negative amount). If AUCTIONFEES + AUCTIONFEES_GST >= TOTALSURPLUS then ACTUALPAYMENT is zero
SQL Type: NUMBER(15,5)
Polars Type: pl.Float64
This column is not mandatory.
AUCTIONFEES_GST
The GST amount on the auction fees, always being zero.
SQL Type: NUMBER(15,5)
Polars Type: pl.Float64
This column is not mandatory.
CSP_DEROGATION_AMOUNT
The CSP derogation amount applied as an adjustment to SRA.
SQL Type: NUMBER(18,8)
Polars Type: pl.Float64
This column is not mandatory.
LASTCHANGED
Date and time this record was last modified
For more information, see the dedicated documentation page.
SQL Type: DATE
Polars Type: pl.Datetime()
This column is not mandatory.
Example: 2026/01/20 00:05:00
NEGATIVE_RESIDUES
Negative residues in the billing week for this participant in the SRA Year/Quarter
SQL Type: NUMBER(18,8)
Polars Type: pl.Float64
This column is not mandatory.
TOTALSURPLUS
Total residue amount allocated to participant
SQL Type: NUMBER(15,5)
Polars Type: pl.Float64
This column is not mandatory.
UNADJUSTED_IRSR
The SRA amount unadjusted by CSP.
SQL Type: NUMBER(18,8)
Polars Type: pl.Float64
This column is not mandatory.
New Data Timing
After posting of a billing run where there are unpurchased auction units
Code Examples
Polars
Casting is enums, categoricals etc is not essential, but may speed up parsing.
Swapping int for pl.UInt16, pl.Int32 would also speed up parsing. However some of the datatypes are inferred, so they may be wrong.
This code deduplicates for you. Deduplication is normally only required across multiple months.
This code assumes that all columns are present, which may not be true for older files.
import polars as pl
import polars.selectors as cs
# e.g. "2029/03/15 00:05:00"
dt_s_fmt = "%Y/%m/%d %H:%M:%S"
csv_paths = ["SOMEFILE.CSV", "OTHERFILE.CSV"]
lf = (
pl.concat(
[
pl.scan_csv(
csv_path, # must be unzipped beforehand
skip_rows=1, # skip the header
infer_schema=False, # much faster
)
.filter(cs.by_index(0) == "D") # drop the footer
.select(~cs.by_index(range(4))) # drop metadata columns
for csv_path in csv_paths
],
how="diagonal_relaxed",
)
.with_columns(
pl.col("LASTCHANGED").str.strptime(pl.Datetime, dt_s_fmt),
)
.cast(
{
"BILLRUNNO": int, # or pl.UInt16
"CONTRACTYEAR": int, # or pl.UInt16
"FROMREGIONID": pl.Enum(["QLD1", "VIC1", "TAS1", "NSW1", "SA1"]),
"INTERCONNECTORID": pl.Categorical,
"PARTICIPANTID": pl.Categorical,
"QUARTER": int, # or pl.Int8
"RESIDUEYEAR": int, # or pl.Int16
"WEEKNO": int, # or pl.UInt16
"ACTUALPAYMENT": pl.Float64,
"AUCTIONFEES": pl.Float64,
"AUCTIONFEES_GST": pl.Float64,
"CSP_DEROGATION_AMOUNT": pl.Float64,
"NEGATIVE_RESIDUES": pl.Float64,
"TOTALSURPLUS": pl.Float64,
"UNADJUSTED_IRSR": pl.Float64,
}
)
# Deduplicate
# We want one row per ['BILLRUNNO', 'CONTRACTYEAR', 'FROMREGIONID', 'INTERCONNECTORID', 'PARTICIPANTID', 'QUARTER', 'RESIDUEYEAR', 'WEEKNO']
# Tie-breaker: greatest value of ['LASTCHANGED']
.sort(["LASTCHANGED"], descending=False)
.unique(
subset=[
"BILLRUNNO",
"CONTRACTYEAR",
"FROMREGIONID",
"INTERCONNECTORID",
"PARTICIPANTID",
"QUARTER",
"RESIDUEYEAR",
"WEEKNO",
],
keep="last",
)
)
Nemosis
This table is not yet available in Nemosis.
Availability
Visibility: Private
This table is not available in the public monthly MMSDM archive. Is is only available to registered market participants over FTP inside a VPN.
Deduplication and PDR Loader Configuration
The primary keys are:
The transaction type is "insert", which means that you will usually not see duplicate data. If you do, you can deduplicate based on the primary keys, without sorting first. Rows from different files with the same primary keys should have the same values.
| Report Name | Report Subtype | Version |
|---|---|---|
| BILLING | IRAUCSURPLUSSUM | 7 |
This means that the CSV files start with metadata columns:
Indexes
Links
This page as JSON (schema documented here, but may change)
Download a JSON Schema specification for this table.
Official AEMO schema documentation
Other Information
Package: BILLING_RUN