Every Last Joule · Region record

New Zealand Hydro

Provenance, tier, and validation record for new-zealand-hydro. No live curtailment figures on this page — those are on the globe.

Region id
new-zealand-hydro
Country
NZL
Waste modality
Hydro
Coordinates
44.00° S, 170.10° E
Measured Data quality
Tier
live · T1a-live-tso

The transmission system operator publishes an hourly series, and the calibration rate comes from the same jurisdiction.

Live TSO feed, own-jurisdiction rate (±2σ from 5-yr backfill, fallback ±15%)

Uncertainty
±15% of peak GW

Regions with a five-year backfill archive use ±2σ of observed annual variance instead of this default fraction.

Published envelope for this tier. See the uncertainty model.

Source provenance
verified · Verified upstream link

The snapshot value comes from a verified upstream feed or anchor.

Source
EMI DispatchNodalPricesAndVolumes ≤$0/MWh nodal price signal (Waitaki corridor, Manapouri, Waikato) — ≤$0 events are rare in NZ, so this reads a genuine zero most of the time (floor, not a measure of total spill)

https://emidatasets.blob.core.windows.net/publicdata/Datasets/Wholesale/DispatchAndPricing/NodalPricesAndVolumes

Tier, provenance, and source are read at build time from src/lib/regions.ts — the same table the globe draws from. The validation record below is generated separately and gated against it by npm run ci:docs-drift.

Validation record

Last updated: 2026-08-20 · Sprint: S1 + HB integration · Paper section: Technical Validation §4.2

Source

Calibration

  • Rate source documented in: docs/methodology/ (see links below)
  • Uniform across backfill years: n/a — no backfill

Multi-year backfill annual totals

Year Backfill rows Backfill annual TWh Published TSO annual TWh Δ % Source
(no backfill or TSO anchors yet — will be populated after HB fan-out completes)

Published anchors

  • TSO annual curtailment (latest published): —
  • Ember annual: —
  • IRENA annual: —
  • Other: —

Discrepancy analysis

The ≤$0 threshold is conservative: it will miss curtailment that clears at small positive prices due to bilateral contracts or inter-island constraints not reflected in the spot price. This is the same conservatism that the AEMO loader exhibits for soft-SEMIDISPATCHCAP cases. The dataset documents this as a lower bound on actual curtailment.

Only nodes in the static POC fuel map contribute. Well-known but less common hydro nodes (e.g., Clyde CLY2201, Roxburgh ROX0111, Livingstone LIV0332) are not included in v1.4.0 to preserve correctness. Their contribution would increase the hydro total if added.

Known limitations

  1. Static POC map is conservative. Only 13 hydro POC codes are mapped. Nodes outside the map are silently skipped. This means the dataset captures the Waitaki corridor and Manapouri reliably but may miss smaller South Island or North Island hydro nodes.
  2. UTC+12 constant. NZ transitions between NZST (UTC+12) and NZDT (UTC+13). The loader uses UTC+12 constantly, consistent with the existing NZ codebase. This introduces a 1-hour timestamp shift for ~6 months per year. Curtailment totals are unaffected; the time-of-day profile is slightly misaligned during DST.
  3. Recent days unpublished. EMI typically publishes DispatchNodalPricesAndVolumes files 1–2 days after the trading day. The loader fetches 35 days back, stopping when 30 loaded days are accumulated. The data window is therefore usually 2–32 days ago, not 0–30.
  4. Solar coverage is minimal. NZ has few grid-scale solar POCs with known codes; new-zealand-solar will typically show near-zero curtailment from this loader. This is expected and correct — NZ's solar market is small and embedded generation (rooftop) does not appear in dispatch data.

Current GW, 24-hour peak, 30-day TWh, and feed freshness for this region are on the globe. Cite this page as everylastjoule.com/region/new-zealand-hydro. The dataset has a DOI; see About.