GB National Grid Live Telemetry

Data safeguard: why some readings are delayed or missing

This dashboard combines three independently updated sources, Elexon FUELINST generation and interconnector readings, Elexon Market Index Data for wholesale prices, and the Carbon Intensity API. These sources do not always publish their readings at the same time or for the same settlement period.

To avoid presenting an incomplete fuel mix as a complete one, the generation, demand, and decarbonisation summary uses the latest settlement period with a total generation reading. Carbon intensity and wholesale price can update on a different schedule, their summary values show the latest available reading, and hovering over either value shows its reading time. A gap in a chart means that source has no value for that period.

If a feed is delayed, the dashboard may continue to show the latest available or completed readings. A delay does not necessarily mean the electricity system itself is unstable.

Is this dashboard accurate?

It is a best effort view of published grid data, not a direct meter for every generator or a guaranteed real time measurement. Gas, coal, nuclear, biomass, hydro, and interconnector flows come directly from Elexon's FUELINST readings for transmission connected generation and flows.

Solar is not metered by Elexon, and its wind readings cover transmission connected wind farms only. Those figures are supplemented with NESO's Demand Data Update estimates of embedded generation connected to distribution networks, such as rooftop solar. As a result, embedded wind and solar values are estimates.

Battery storage may show -- because Elexon does not currently publish the battery charge/discharge data needed for this breakdown. Fuel percentages are calculated relative to total demand (generation plus net imports and storage discharge, minus storage charging) and may not add up to exactly 100% because of estimates, rounding, and unavailable readings.

Why can figures differ from other dashboards, such as grid.iamkate.com? Dashboards use the same public Elexon and NESO feeds, so their figures should be broadly similar, but may differ because they combine embedded generation differently, calculate demand independently, and refresh on different schedules. Comparing dashboards is comparing independent snapshots and estimates of the same grid, not necessarily identical readings.

Reading the dashboard

• Overview: system balancing volume and frequency over time, with current summary metrics and grid operations.
• Carbon & Fuel Mix: national generation by fuel, carbon intensity, wholesale price, and the fuel and transfer breakdown.
• Regional carbon intensity: the first 24 hour heatmap is coloured by carbon intensity category. Hover over a cell for its time, dominant fuel, exact gCO₂/kWh value, and category.
• Regional primary fuel: the second heatmap uses a separate colour for each primary fuel. Its legend identifies the fuel, and hovering over a cell shows the fuel and the reading details.

Charts use half hour settlement period readings where available, aligning them with Great Britain's half hourly wholesale marginal pricing periods. Hover over an interactive chart to inspect values, drag across it to zoom, and double click to reset the time range. Values are reported in the units shown on each chart or metric, GW is generation or demand in MW divided by 1,000.

Use the period links to view Today, Previous Day, 3 Days, Week, Month, Year, or Previous Year. The regional heatmaps have their own selector for the most recent 24 hours or the previous calendar day.

Imports, exports, and prices

Interconnector values are shown from Great Britain's perspective, positive values indicate imports and negative values indicate exports. The wholesale price is a system wide market price for a settlement period, not a separate price for each fuel type.

Public JSON datasets

The dashboard's exported datasets are available as JSON files in the public UK Grid Tracker GitHub repository. They can be downloaded and used by anyone, no dashboard account is required. The repository includes national time series for different periods, regional readings, and carbon intensity forecasts.

Time series files use a compact table format, columns lists the field names, and each item in rows contains the corresponding values in that column order. The files can be inspected in a browser, downloaded, or read by scripts and other applications.

The JSON exports combine data from upstream providers. If you reuse or redistribute them, check and follow the providers' applicable terms, licences, and attribution, in particular, see Elexon's BMRS data licence.

Data sources and contact

• Elexon Insights Solution - generation, system, and market data.
• National Energy System Operator (NESO) Data Portal - demand data and embedded generation estimates.
• Carbon Intensity API - carbon intensity data.

For questions or suggestions, contact support@ukpoliticsdecoded.uk. This dashboard is an independent informational project and is not an official government or system operator service.