Carbon Intensity API (Great Britain)

Carbon Intensity API (Great Britain)

A keyless JSON REST API for the carbon intensity and generation mix of electricity in Great Britain, nationally and by region, as both forecasts and estimates from metered generation. Built by the National Energy System Operator (NESO) with Environmental Defense Fund Europe, the University of Oxford Department of Computer Science and WWF. The site's Terms of Use section says: "Our API is licensed under the CC BY 4.0 license. The Terms of Use are available below."

Coverage

Carbon intensity in gCO2/kWh and generation mix by fuel type in half-hour settlement periods, for Great Britain as a whole and for 14 geographical regions ("NESO forecasts the carbon intensity and generation mix of electricity consumed across 14 geographical regions in Great Britain.") plus England, Scotland and Wales and postcode lookups; forecast and actual values, with statistics endpoints for averages, maxima and minima. The site says the API is used "to forecast the carbon intensity and generation mix 96+ hours ahead for each region in Great Britain", while the API documentation's own summary says "up to 2 days ahead of real-time". History on the site's CSV download tool: "Data is only available after 2017-09-26." Per-call date ranges are capped (intensity between two datetimes: "The maximum date range is limited to 14 days"; statistics endpoints: 30 days).

Verdict

Half-hourly carbon intensity and generation mix for Great Britain and its regions, forecast and estimated, from a keyless JSON API. Licensed CC BY 4.0 on the provider's own wording: "Our API is licensed under the CC BY 4.0 license. The Terms of Use are available below.", and the API documentation lists "License: CC BY 4.0". WARNING: the separate Terms of Use page the site links (a plain-http terms.carbonintensity.org.uk address) returned no response on the 2026-11-09 check, so only the licence statements on the site and in the documentation could be read. The regional and generation-mix endpoints are labelled beta. Distinct from neso-open-data-api, which is NESO's CKAN data portal on a different host. Rate limits: Not stated. Signal Lab links only.