UK Electricity Data Sources
EnergyMix.info combines public electricity and carbon-intensity data sources to explain Britain’s live power mix in plain English. This page sets out what each source is used for, why figures can differ between dashboards, and where the important limitations are.
At a glance
The dashboard blends fast live feeds with slower settlement-period and forecast sources. The goal is useful public grid context, not billing-grade metering or an official system-operator publication.
| Data area | Source | Used for | Limitation |
|---|---|---|---|
| Generation by fuel | Elexon BMRS/FUELINST and related public GB electricity feeds | Live electricity mix, wind, gas, nuclear, hydro, biomass and other visible generation categories | Transmission and settlement feeds can lag, revise and treat embedded generation differently from other dashboards |
| Demand | NESO/Elexon public demand data where available | Current GB demand context and daily/weekly summaries | Demand definitions can differ from total generation because imports, exports, storage and embedded sources are handled differently |
| Carbon intensity | Carbon Intensity API | National, regional and postcode carbon-intensity estimates and forecasts | Carbon intensity is an estimate and forecast, not a physical meter reading for each unit of electricity |
| Solar | Embedded solar estimates including Sheffield Solar PV Live and NESO demand data where needed | Solar generation context, daily summaries and validation backfill | Much UK solar is embedded/distribution-connected, so it is often estimated rather than directly visible in transmission generation feeds |
| Interconnectors | ENTSO-E, BMRS-derived and related public flow data | Import/export context and neighbouring-system signals | Flow conventions, sign direction and carbon impact can vary by source and market context |
Primary Sources
Why numbers differ between dashboards
Electricity dashboards can be correct while showing different numbers. The usual reasons are coverage, timing and category treatment rather than one site being “right” and another being “wrong”.
- GB vs UK coverage: many live feeds cover Great Britain, while Northern Ireland uses a separate electricity market.
- Embedded generation: solar and some wind can sit outside transmission-connected generation feeds and may need estimates.
- Settlement timing: some values update around 30-minute settlement periods while others refresh more frequently.
- Imports, exports and storage: dashboards may show these separately, net them out, or include them in different totals.
- Rounding and revisions: public data can lag or be revised after the first live publication.
Renewables and low-carbon definitions
Renewable electricity usually means wind, solar, hydro and sometimes biomass depending on the accounting convention. Low-carbon electricity is broader because it normally includes nuclear as well.
EnergyMix.info keeps these ideas separate where possible. Renewable share helps explain weather-led generation, while low-carbon share and carbon intensity help explain the emissions context.
Update Frequency
Energy Mix uses a multi-tier refresh system designed to feel live while staying gentle on public APIs. Fast-changing generation is polled more often; slower settlement-period data is refreshed on a steadier cadence.
High Frequency — Every 2 minutes
Transmission-connected generation from Elexon FUELINST's 5-minute feed, plus the latest embedded wind and solar estimates where available. This keeps the visible mix moving much closer to live.
Mid Frequency — Every 5 minutes
Interconnector flows and European generation mix from ENTSO-E/BMRS fallbacks. These update frequently enough for live dashboard use without hammering the upstream services.
Full Refresh — Every 10 minutes
Complete data refresh including demand outturn, embedded sources, interconnectors, EU data, and carbon intensity forecasts. Settlement-period datasets still update at their native 30-minute cadence.
Updates are staggered to prevent simultaneous API requests and reduce load on data providers. The dashboard also refreshes automatically when you return to the tab after being away.
Data roadmap and known gaps
The live dashboard now covers the core electricity mix well. The next data improvements are about practical usefulness: price, storage, regional carbon and reusable access.
Wholesale price
Useful for “cleanest vs cheapest” guidance. EnergyMix now pulls Elexon Market Index Price as wholesale context; it is not a consumer tariff or smart-tariff recommendation.
Storage and pumped storage
Pumped storage is now shown by state: charging/pumping when PS is negative, generating when PS is positive. This avoids hiding storage inside generation noise.
Regional carbon
Regional and postcode carbon forecasts are now exposed on the carbon-intensity page using NESO’s Carbon Intensity API.
API and embeds
A public widget/API surface is the next packaging opportunity: embeddable Power Flow, daily summary cards and lightweight JSON endpoints for partners.
API, widget and embed interest
EnergyMix.info is being shaped so the clearest parts can be reused elsewhere: a small Power Flow widget, clean-electricity timing cards, daily summary images and selected machine-readable data.
Licenses & Attribution
This service uses data made available under open licenses. We are required to provide the following attributions:
Elexon BMRS Data
Contains BMRS data © Elexon Limited copyright and database right 2026. Licensed under the Elexon Open Data License.
NESO Data
Contains data from the National Energy System Operator (NESO), licensed under the NESO Open Licence, which is based on the Open Government Licence v3.0.
Carbon Intensity Data
Carbon intensity forecasts provided by the National Energy System Operator via the Carbon Intensity API.