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SETIRSURPLUS

SETIRSURPLUS records the interregional residue calculation for each interconnector and each side of the interconnector.

SETIRSURPLUS data is public, so is available to all participants.

Source

SETIRSURPLUS updates once a day at 8am.

Note

MWFLOW and LOSSFACTOR are now both calculated as MWh (energy) values for the half hour, and not MW (average demand) values. By way of clarification, the MWFLOW value is derived from half-hour revenue class metering, adjusted by a fixed fraction of the LOSSFACTOR value. The LOSSFACTOR value is taken to be exactly half of the MWLOSSES value in the TRADINGINTERCONNECT table.

The METEREDMWFLOW field in the TRADINGINTERCONNECT table contains averaged SCADA metering demand values available in “real time”, whereas the MWFLOW field in the SETIRSURPLUS table contains settlement energy metering values available only after a settlement run is posted.

Column Schema

INTERCONNECTORID

Interconnector

SQL Type: VARCHAR2(10) Polars Type: pl.Categorical

This column is mandatory, and a primary key.

Examples:

  • N-Q-MNSP1
  • NSW1-QLD1
  • T-V-MNSP1
  • V-S-MNSP1
  • V-SA
  • VIC1-NSW1

PERIODID

Settlements Trading Interval.

SQL Type: NUMBER(3,0) Polars Type: pl.Int16

This column is mandatory, and a primary key.

Examples: 1, 84

REGIONID

Side of 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

  • SNOWY1

This column is mandatory, and a primary key.

SETTLEMENTDATE

Settlement date

SQL Type: DATE Polars Type: pl.Date()

This column is mandatory, and a primary key.

Example: 2026/08/31 00:00:00

Note that AEMO represents dates as datetimes with a midnight time component.

SETTLEMENTRUNNO

Settlement run number

SQL Type: NUMBER(3,0) Polars Type: pl.UInt16

This column is mandatory, and a primary key.

Example: 1

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.

Example: 0

LASTCHANGED

Last date and time record changed

For more information, see the dedicated documentation page.

SQL Type: DATE Polars Type: pl.Datetime()

This column is not mandatory.

Example: 2026/09/01 01:12:12

LOSSFACTOR

MW losses along interconnector NOTE: This is not a loss factor, but a loss figure expressed in MWH

SQL Type: NUMBER(15,5) Polars Type: pl.Float64

This column is not mandatory.

Examples: -0.00083, 0.00167, 0, 11.11583

MWFLOW

Net flow at the regional node (MWh), including losses

SQL Type: NUMBER(15,6) Polars Type: pl.Float64

This column is not mandatory.

Examples: -0.43895, 0.357283, 0, -38

SURPLUSVALUE

Amount of surplus in $

SQL Type: NUMBER(15,5) Polars Type: pl.Float64

This column is not mandatory.

Examples: -0.81316, 0.90787, 0, 3115.15178

UNADJUSTED_IRSR

The SRA amount unadjusted by CSP

SQL Type: NUMBER(18,8) Polars Type: pl.Float64

This column is not mandatory.

Examples: -0.81315917, 0.90787332, 0, 3115.15177987

New Data Timing

Daily at 8 am

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"

# Dates are represented as datetimes at midnight

d_fmt = "%Y/%m/%d 00:00:00"

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),
        pl.col("SETTLEMENTDATE").str.strptime(pl.Date, d_fmt),
    )
    .cast(
        {
            "INTERCONNECTORID": pl.Categorical,
            "PERIODID": int,  # or pl.Int16
            "REGIONID": pl.Enum(["QLD1", "VIC1", "TAS1", "NSW1", "SA1", "SNOWY1"]),
            "SETTLEMENTDATE": pl.Date(),
            "SETTLEMENTRUNNO": int,  # or pl.UInt16
            "CSP_DEROGATION_AMOUNT": pl.Float64,
            "LOSSFACTOR": pl.Float64,
            "MWFLOW": pl.Float64,
            "SURPLUSVALUE": pl.Float64,
            "UNADJUSTED_IRSR": pl.Float64,
        }
    )
    # Deduplicate
    # We want one row per ['INTERCONNECTORID', 'PERIODID', 'REGIONID', 'SETTLEMENTDATE', 'SETTLEMENTRUNNO']
    # Tie-breaker: greatest value of ['LASTCHANGED']
    .sort(["LASTCHANGED"], descending=False)
    .unique(
        subset=[
            "INTERCONNECTORID",
            "PERIODID",
            "REGIONID",
            "SETTLEMENTDATE",
            "SETTLEMENTRUNNO",
        ],
        keep="last",
    )
)

Nemosis

This table is not yet available in Nemosis.

Example File

From PUBLIC_ARCHIVE_SETIRSURPLUS_FILE01_202609010000.zip

SETTLEMENTDATESETTLEMENTRUNNOPERIODIDINTERCONNECTORIDREGIONIDMWFLOWLOSSFACTORSURPLUSVALUELASTCHANGEDCSP_DEROGATION_AMOUNTUNADJUSTED_IRSR
2026/08/31 00:00:0011N-Q-MNSP1NSW13.813750.372502026/09/01 01:12:1200
2026/08/31 00:00:0011N-Q-MNSP1QLD1-4.186250.372531.92192026/09/01 01:12:12031.9219
2026/08/31 00:00:0011NSW1-QLD1NSW188.1971337.9383302026/09/01 01:12:1200
2026/08/31 00:00:0011NSW1-QLD1QLD1-96.1354677.93833791.460982026/09/01 01:12:120791.46097799
2026/08/31 00:00:0011T-V-MNSP1TAS1-35.9166672.21333134.798872026/09/01 01:12:120134.79886669
2026/08/31 00:00:0011T-V-MNSP1VIC133.7033332.2133302026/09/01 01:12:1200
2026/08/31 00:00:0011V-S-MNSP1SA10002026/09/01 01:12:1200
2026/08/31 00:00:0011V-S-MNSP1VIC10002026/09/01 01:12:1200
2026/08/31 00:00:0011V-SASA111.1186920.0891702026/09/01 01:12:1200
2026/08/31 00:00:0011V-SAVIC1-11.2078580.0891717.875932026/09/01 01:12:12017.87593017
2026/08/31 00:00:0011VIC1-NSW1NSW15.7926580.3441702026/09/01 01:12:1200
...

CSETP.WORLDDVD_SETIRSURPLUSAEMOPUBLIC2026/10/0916:33:01001791527581141MONTHLY_ARCHIVE001791527581141
ISETTLEMENTSIRSURPLUS6SETTLEMENTDATESETTLEMENTRUNNOPERIODIDINTERCONNECTORIDREGIONIDMWFLOWLOSSFACTORSURPLUSVALUELASTCHANGEDCSP_DEROGATION_AMOUNTUNADJUSTED_IRSR
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011N-Q-MNSP1NSW13.813750.372502026/09/01 01:12:1200
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011N-Q-MNSP1QLD1-4.186250.372531.92192026/09/01 01:12:12031.9219
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011NSW1-QLD1NSW188.1971337.9383302026/09/01 01:12:1200
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011NSW1-QLD1QLD1-96.1354677.93833791.460982026/09/01 01:12:120791.46097799
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011T-V-MNSP1TAS1-35.9166672.21333134.798872026/09/01 01:12:120134.79886669
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011T-V-MNSP1VIC133.7033332.2133302026/09/01 01:12:1200
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011V-S-MNSP1SA10002026/09/01 01:12:1200
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011V-S-MNSP1VIC10002026/09/01 01:12:1200
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011V-SASA111.1186920.0891702026/09/01 01:12:1200
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011V-SAVIC1-11.2078580.0891717.875932026/09/01 01:12:12017.87593017
DSETTLEMENTSIRSURPLUS62026/08/31 00:00:0011VIC1-NSW1NSW15.7926580.3441702026/09/01 01:12:1200
...
CEND OF REPORT1003

SETTLEMENTDATE,SETTLEMENTRUNNO,PERIODID,INTERCONNECTORID,REGIONID,MWFLOW,LOSSFACTOR,SURPLUSVALUE,LASTCHANGED,CSP_DEROGATION_AMOUNT,UNADJUSTED_IRSR
"2026/08/31 00:00:00",1,1,N-Q-MNSP1,NSW1,3.81375,0.3725,0,"2026/09/01 01:12:12",0,0
"2026/08/31 00:00:00",1,1,N-Q-MNSP1,QLD1,-4.18625,0.3725,31.9219,"2026/09/01 01:12:12",0,31.9219
"2026/08/31 00:00:00",1,1,NSW1-QLD1,NSW1,88.197133,7.93833,0,"2026/09/01 01:12:12",0,0
"2026/08/31 00:00:00",1,1,NSW1-QLD1,QLD1,-96.135467,7.93833,791.46098,"2026/09/01 01:12:12",0,791.46097799
"2026/08/31 00:00:00",1,1,T-V-MNSP1,TAS1,-35.916667,2.21333,134.79887,"2026/09/01 01:12:12",0,134.79886669
"2026/08/31 00:00:00",1,1,T-V-MNSP1,VIC1,33.703333,2.21333,0,"2026/09/01 01:12:12",0,0
"2026/08/31 00:00:00",1,1,V-S-MNSP1,SA1,0,0,0,"2026/09/01 01:12:12",0,0
"2026/08/31 00:00:00",1,1,V-S-MNSP1,VIC1,0,0,0,"2026/09/01 01:12:12",0,0
"2026/08/31 00:00:00",1,1,V-SA,SA1,11.118692,0.08917,0,"2026/09/01 01:12:12",0,0
"2026/08/31 00:00:00",1,1,V-SA,VIC1,-11.207858,0.08917,17.87593,"2026/09/01 01:12:12",0,17.87593017
"2026/08/31 00:00:00",1,1,VIC1-NSW1,NSW1,5.792658,0.34417,0,"2026/09/01 01:12:12",0,0
...

C,SETP.WORLD,DVD_SETIRSURPLUS,AEMO,PUBLIC,2026/10/09,16:33:01,001791527581141,MONTHLY_ARCHIVE,001791527581141
I,SETTLEMENTS,IRSURPLUS,6,SETTLEMENTDATE,SETTLEMENTRUNNO,PERIODID,INTERCONNECTORID,REGIONID,MWFLOW,LOSSFACTOR,SURPLUSVALUE,LASTCHANGED,CSP_DEROGATION_AMOUNT,UNADJUSTED_IRSR
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,N-Q-MNSP1,NSW1,3.81375,0.3725,0,"2026/09/01 01:12:12",0,0
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,N-Q-MNSP1,QLD1,-4.18625,0.3725,31.9219,"2026/09/01 01:12:12",0,31.9219
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,NSW1-QLD1,NSW1,88.197133,7.93833,0,"2026/09/01 01:12:12",0,0
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,NSW1-QLD1,QLD1,-96.135467,7.93833,791.46098,"2026/09/01 01:12:12",0,791.46097799
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,T-V-MNSP1,TAS1,-35.916667,2.21333,134.79887,"2026/09/01 01:12:12",0,134.79886669
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,T-V-MNSP1,VIC1,33.703333,2.21333,0,"2026/09/01 01:12:12",0,0
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,V-S-MNSP1,SA1,0,0,0,"2026/09/01 01:12:12",0,0
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,V-S-MNSP1,VIC1,0,0,0,"2026/09/01 01:12:12",0,0
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,V-SA,SA1,11.118692,0.08917,0,"2026/09/01 01:12:12",0,0
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,V-SA,VIC1,-11.207858,0.08917,17.87593,"2026/09/01 01:12:12",0,17.87593017
D,SETTLEMENTS,IRSURPLUS,6,"2026/08/31 00:00:00",1,1,VIC1-NSW1,NSW1,5.792658,0.34417,0,"2026/09/01 01:12:12",0,0
...
C,"END OF REPORT",1003

Availability

Visibility: Public

This table is in the public monthly MMSDM archive.

I have collated the list of all those files into one place, in this CSV metadata file. (Columns year, month, url, compressed_size in bytes).

The earliest available data is month 1 of 2015. The most recent available data is month 9 of 2026.

Warning

There are some months with no files.

Data Size

Each year of data is approximately 124 MB when zipped, 1 GB as unzipped CSV.

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.

PDR Loader configuration is:

Report Name Report Subtype Version
SETTLEMENTS IRSURPLUS 6

This means that the CSV files start with metadata columns:

I,SETTLEMENTS,IRSURPLUS,6,...
D,SETTLEMENTS,IRSURPLUS,6,...

Indexes

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: SETTLEMENT_DATA