data(nordic): per-zone carbon intensity for Norwegian bidding zones NO1–NO5

[avalyset]

data(nordic): per-zone carbon intensity for Norwegian bidding zones NO1–NO5

Hi! This proposes replacing the uniform 18.0 gCO2eq/kWh placeholder currently shared by all five Norwegian bidding zones in codecarbon/data/private_infra/nordic_emissions.json with per-zone, derived values. Data-only change — happy to adjust anything based on your review.

What

Zone	before	after (gCO2eq/kWh)
NO1 (Oslo)	18.0	23.3
NO2 (Southern)	18.0	23.9
NO3 (Central)	18.0	21.5
NO4 (Northern)	18.0	39.6
NO5 (Western)	18.0	24.5

SE1–SE4 and FI are unchanged (byte-for-byte; only NO blocks + file metadata touched).

Why the placeholder is worth improving

The current 18.0 is identical across NO1–NO5 (so it can't distinguish the zones) and reads low for every zone — and ~2.2× low for NO4 (39.6), which carries persistent fossil-gas generation. A single value can't represent the five zones; NO4 in particular is structurally different.

Source & method (aligned with CodeCarbon's own fallback)

• Source: ENTSO-E Transparency Actual Generation per Production Type (A75), per bidding zone, full year 2025.
• Method: production-based generation-mix — weighted average of each generation source × its lifecycle factor. This matches the approach CodeCarbon's own static fallback already documents ("weighted average of the emissions from the different energy sources used to generate electricity").
• These values replace the production fallback; they do not touch the Electricity Maps API path, which remains the consumption-based (import-adjusted) source when a token is configured.

A point we'd like your steer on: the factor basis

We derived these with IPCC AR5 Annex III (Table A.III.2) lifecycle medians (coal 820, gas 490, hydro 24, wind 11, …) rather than CodeCarbon's carbon_intensity_per_source.json (coal 995 / gas 743 direct-combustion + WNA-lifecycle for low-carbon). Our reasoning:

• IPCC AR5 is a single, peer-reviewed, consistent-lifecycle basis, and it keeps these numbers identical to the upstream derivation's DOI-frozen record (so there's one citable value per zone, not two).
• Using AR5 (gas 490 vs 743) makes the NO values slightly conservative relative to CodeCarbon's own gas factor.

That said — this is a recommendation, not a correction of your table. If you'd prefer internal consistency with carbon_intensity_per_source.json, re-deriving with your own per-source factors is a one-line change on our side; just say the word. What matters to us is that NO gets real per-zone numbers.

Honest characterization (per-zone notes added, not just five numbers)

A multi-year analysis (2021–2025) is carried in the per-zone note fields, because a bare NO4 number would mislead:

• NO1/NO2/NO3: stable year-over-year (<5% drift) → annual update is sufficient.
• NO4: event-driven, not a stable constant — driven by Hammerfest LNG gas turbines, which were offline after a Sept-2020 fire and restarted June 2022 (source). NO4 CI ranged 23–51 gCO2eq/kWh across 2021–2024; the 39.6 value is period-dependent.
• NO5: sits near the hydro lifecycle floor (~24) in pure-hydropower periods.
• Honest limit, stated plainly: production-based NO carbon intensity is low and not very distinct between zones except where fossil gas occurs (NO4).

Reproducibility

Every value is traceable. Derivation method, pre-registered before computation, is in the ADR chain (esp. ADR-0001 CI method); the per-zone results and the multi-year drift analysis are in the repo's docs/. Frozen and citable:

• Repository: https://github.com/avalyset/khepri
• DOI (concept, all versions): 10.5281/zenodo.21042581

Tests

CodeCarbon's existing Nordic tests read the factor values dynamically from the JSON and pass unchanged with the new values (verified locally). No code changes — data only.

Thanks for maintaining CodeCarbon — glad to iterate on any of this.

[avalyset]

Hi @benoit-cty — a note in the same spirit as the one on #1262, for the
zone that carries the strongest claim in this set.

Our docs/ mix figures report each type's energy-weighted share of total generation,
while the headline CI normalises over the factor-carrying types — same weighting,
different denominator (full explanation on #1262). For NO4 the excluded category is
"Other renewable" (1.35%); the four types below carry 98.65% of generation and
reproduce the headline exactly.

NO4 (2025) — energy/duration-weighted decomposition

• Interval coverage: 100.00% (27912 / 27912 intervals)
• Factors: IPCC AR5 Annex III lifecycle medians (per src/khepri/factors.py)

Production type	Energy share	AR5 factor (gCO2eq/kWh)	Contribution
Hydro Water Reservoir	77.2411 %	24	18.5379
Wind Onshore	11.6688 %	11	1.2836
Hydro Run-of-river and poundage	7.4069 %	24	1.7777
Fossil Gas	3.6832 %	490	18.0477
Total			39.6468 → 39.65

Contributions are display-rounded to 4 decimals; the column as printed sums to 39.6469 against the exact 39.6468.

The point worth making visible: Fossil Gas is only 3.68 % of the mix but 18.05 of
39.65 gCO2eq/kWh — 45.5 % of NO4's carbon intensity. That is precisely why NO4
separates from the other Norwegian zones (all ≈21–24.5, hydro-dominated): a persistent
gas share at a factor of 490 dominates the number despite a small mix share. This
is the value the uniform 18.0 placeholder is most wrong about, so it is the one that
most deserves a visible calculation.

Full method, EIC codes, and the same-weighting/different-denominator explanation are
in #1262; happy to provide the same decomposition for NO1–NO3 and NO5 on request.