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Changelog

Source: NEWS.md

aemo 0.4.2

Maintenance release fixing a network-dependent test that could fail the package check whenever the NEMweb archive was unreachable.

aemo_fcas_enablement() validated its service argument only after fetching dispatch data, so an unknown service name surfaced the underlying fetch error (for example “NEMweb returned HTTP 403”) rather than the intended “No matching FCAS service columns” message. On check machines that could not reach NEMweb this broke the bad-service-name test in test-dispatch.R, producing an intermittent R CMD check ERROR on the flavours where the archive happened to be unreachable.

The service argument is now validated before any network request, so a bad name fails fast and offline. No change for valid calls.

aemo 0.4.1

CRAN release: 2026-05-27

Maintenance release fixing a test-suite issue reported by CRAN on 2026-05-27. The aemo_units() integration test made a live MMSDM request without a skip_on_cran() guard, so it raised an error on CRAN check machines whenever the NEMweb archive was unreachable. The test is now guarded like the other network-dependent tests and split into a gated live check and an offline-abort check that verifies the no-fallback behaviour. No user-facing code changes.

aemo 0.4.0

CRAN release: 2026-04-28

First release under new maintainership. Reclaims the archived aemo package name (Imanuel Costigan, 2014-2020, v0.1.0 to v0.3.0, archived 2021-12-29). The prior package shipped three functions covering regional prices and demand only; this release is an independent rewrite covering the full NEMweb and MMSDM data surface and shares only the package name.

Version starts at 0.4.0 to sit strictly above the last archived version (0.3.0).

Data functions

Price and demand

  • aemo_price(): 5-min (DISPATCHPRICE) or 30-min (TRADINGPRICE) regional wholesale prices. Pre-5MS (before 2021-10-01) reads TRADINGIS; post-5MS 30-min prices are derived as the arithmetic mean of six 5-min dispatch prices within each trading interval, matching AEMO’s post-5MS TRADINGPRICE derivation.
  • aemo_demand(): regional operational, operational-less-SNSG, or native demand at 5-min resolution.
  • aemo_price_caps(): static reference table of Market Price Cap, Floor, CPT, and APC by financial year. Per-row source citations to the specific AEMC determination.

Dispatch and flow

  • aemo_dispatch_units(): per-DUID generator output at 5-min. measure = "scada_mw" (default) returns SCADA actual; "target_mw" returns DISPATCHLOAD TOTALCLEARED; "both" returns INITIALMW + TOTALCLEARED + SCADAVALUE paired, enabling ramp-trajectory research.
  • aemo_interconnector(): NEM interconnector flows.
  • aemo_rooftop_pv(): estimated rooftop PV actual or forecast.
  • aemo_fcas(), aemo_fcas_enablement(): FCAS prices and enablement across the ten services live since 9 Oct 2023.
  • aemo_constraints(): binding transmission and system constraints with shadow prices.
  • aemo_gencon(): GENCONDATA constraint equations.
  • aemo_spd_constraints(): SPD constraint coefficient tables (SPDREGIONCONSTRAINT, SPDINTERCONNECTORCONSTRAINT, SPDCONNECTIONPOINTCONSTRAINT). Required for nempy-style dispatch replication (Gorman et al. 2022 JOSS 7(70) 3596).
  • aemo_outages(): NETWORK_OUTAGEDETAIL.
  • aemo_market_notices(): MARKETNOTICEDATA feed (LOR, RERT, interventions, suspensions). Pairs with the above for market- event forensics (Rangarajan et al. 2025, Energy Economics 141).

Bids and forecasts

  • aemo_bids(): generator bid stack. resolution = "day" (BIDDAYOFFER_D), "period" (BIDPEROFFER_D), or "joined" (the two inner-joined on (duid, settlementdate, bidtype) so price bands and volumes are accessible together).
  • aemo_predispatch(): P5MIN or PREDISPATCH forecasts. Pass run_datetime to pin a specific forecast vintage (required for forecast-error research; mirrors NEMSEER’s workflow, Prakash 2023 JOSS 8(92) 5883).
  • aemo_pasa(): short-term or medium-term projected assessment of system adequacy. Default windows are horizon-aware.

Gas

Reference and settlement

  • aemo_units(): DUID registry. as_of argument performs an effective-date join on DUDETAILSUMMARY so historical queries see the registry as it was at any point in time (e.g. Liddell’s DUIDs pre-2023 retirement).
  • aemo_participants(): PARTICIPANT + DUDETAILSUMMARY.
  • aemo_regions(), aemo_interconnectors(): static metadata.
  • aemo_mlf(), aemo_dlf(): marginal and distribution loss factors from MMSDM.
  • aemo_settlement(): SETCFM (energy cashflow), SETFCASREGIONRECOVERY (FCAS recovery), and SETRESIDUECONTRACTPAYMENT (settlement residues) for gentailer reconciliation workflows.

Reproducibility

  • aemo_snapshot(): returns a provenance record (source URL, SHA-256 of the table body, row count, retrieved-at timestamp) suitable for Zenodo deposit or paper appendix.

Low-level access and configuration

Conventions

  • All timestamps are POSIXct in Australia/Brisbane (AEST, UTC+10, no DST). NER cl. 2.2.6. Using Australia/Sydney would silently shift every summer interval by one hour.
  • Period-ending timestamps throughout.
  • intervention = FALSE (default) filters DISPATCHPRICE to the market pricing run (INTERVENTION = 0) used in settlement. Pass intervention = TRUE for intervention runs (e.g. the June 2022 NEM suspension).
  • options("aemo.base_url") and options("aemo.mmsdm_base") override the NEMweb host endpoints, supporting the 30 April 2026 NEMweb URL migration without a reinstall.

Data source

Data is published by AEMO at http://nemweb.com.au under the AEMO Copyright Permissions Notice https://www.aemo.com.au/privacy-and-legal-notices/copyright-permissions. Downloads are cached to tools::R_user_dir("aemo", "cache") on first use, with SHA-256 content verification on reuse.