South Wales grid, by the half hour.

Region 7 cut of DS-001 with the generation mix pivoted to columns, for the notebook’s local questions.

released CC BY 4.0

Key specificationsas released

Source	NESO Carbon Intensity API (api.carbonintensity.org.uk)
Licence	CC BY 4.0 · attribute NESO
Coverage	May 2018 → yesterday · region 7
Cadence	30 minutes
Units	gCO₂ per kWh · % of generation

Formats	Parquet · CSV from the explorer
Refresh	daily, with DS-001
Revision	2026-10-01
Status	released

Characteristic curvesFig. 1–2 · built 2026-11-09

Fig. 1 · National daily mean, Sept 26 → Nov 26gCO₂/kWh

270180900

mean 122 260 · 8 Nov 49 · 9 Oct

SeptOctNov

69 days, one column each. Daily mean of the national half-hourly series (measured where published, forecast otherwise). Refreshed by the pipeline; the first release used NESO's stats endpoint, whose 30-day windows skip six month-end days.

Fig. 2 · South Wales (region 7), half-hourly forecast, 2026-09-29gCO₂/kWh

4002000

00:0006:0012:0018:0024:00

Shaded by NESO's index band, very low (lightest) to very high. Minimum 18 g at 09:30, maximum 322 g at 17:00. The notebook's sheet 02 reads this day.

Pinout · schemaone row per settlement period

Field	Type	Description
from, to	timestamp (UTC)	Settlement period.
intensity_forecast, intensity_index	int · enum	As DS-001; regional, so forecast only.
mix_gas, mix_wind, mix_solar, mix_nuclear, mix_biomass, mix_imports, mix_hydro, mix_coal, mix_other	float (%)	Forecast share of regional generation.

Absolute maximum ratings · known limitsread before use

Limit	Consequence
A view, not a new source	DS-002 is DS-001 filtered to regionid = 7. Every limit of DS-001 applies.
Forecast only	No measured regional intensity exists.

Typical applicationDuckDB, runs in your browser

SELECT time, intensity_forecast, intensity_index
FROM   sample
WHERE  region = 'sw' AND day = '2026-09-29'
ORDER  BY intensity_forecast LIMIT 5;

Loads DuckDB-WASM on first run (~5 MB, cached by your browser).

The five cleanest half hours of the notebook’s Monday.

Downloadfiles are the release; the site is the label

datapackage.json checks.log sample_days.parquet national_daily_means.parquet

Yearly and monthly partitions (national/, regional/) are listed in datapackage.json once the pipeline has run; the explorer registers them automatically.

Provenance

Derived from	DS-001 regional partitions, WHERE regionid = 7
Checks	Inherited from DS-001

Used in

Notebook	Notebook sheet 02 · The grid, one Monday

Revision history

2026-10-01	v1 · first release, as a view of DS-001.

Cite as

Elliott, J. (2026). DS-002 South Wales grid, by the half hour [data set], databased.business, rev 2026-10-01. Derived from NESO Carbon Intensity API, CC BY 4.0.

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