Gridstate presents observable system state from named public sources. It does not evaluate, recommend, or rank. This page defines how every value shown in the product is measured, so any figure can be traced back to its source and reproduced. Current source health is on the data status page.
Gridstate covers the 14 Distribution Network Operator (DNO) regions of Great Britain, matching the regions of the NESO Carbon Intensity API. A collection run executes every 30 minutes; each run stores one timestamped reading per region, so the historical record accumulates at half-hourly resolution.
The percentage of half-hourly settlement periods in the trailing 48 hours (96 periods) in which at least one SO-flagged balancing acceptance was recorded for a generation unit attributed to the region.
Source: Elexon BMRS BOALF (Bid-Offer Acceptance Level Flagged) records, filtered to acceptances flagged as System Operator actions - the flag Elexon applies to actions taken for system (typically network-constraint) reasons rather than energy balancing. Balancing Mechanism Units are attributed to DNO regions through a curated BMU→region mapping; coverage (the share of SO-flagged acceptances resolved to a region) is typically in the 70-80% range and varies by run. The exact coverage of each run is stored with the reading and shown live alongside the figures it supports. Figures are indicative and pre-settlement.
The volume-weighted average price (£/MWh) of accepted SO-flagged constraint bids for the region over the trailing 48 hours, priced by matching Elexon BOD (Bid-Offer Data) to the accepted BOALF volumes. Negative values mean units were paid to reduce output.
This value has three distinct states, and the product never blurs them: a priced figure; no SO actions (a genuine zero - no constraint activity in the window); and data unavailable (the source could not be fetched - a gap, not a zero).
Regional carbon intensity (gCO₂/kWh) and the generation fuel mix are NESO Carbon Intensity API regional estimates. Renewable share is the sum of the wind, solar, and hydro percentages of the mix. Biomass is deliberately excluded from the renewable share because its classification is contested; it remains visible in the full generation mix.
The 48-hour forward viewuses the same API’s published regional forecast. Forecast values are always labelled as forecasts. Where the product relates a forecast to history (for example, how often past readings matched a forecast renewable share), the statement describes the region’s own historical record - a stated frequency, not a prediction.
The day-ahead wholesale price from Elexon’s Market Index Data (N2EX, with APX fallback). Great Britain has a single national day-ahead price - there is no regionally traded day-ahead market - so the same figure is shown for every region. It is displayed for context alongside the regional indices, which is where regional variation appears.
The UK averageshown against any regional value is the unweighted mean of the 14 regional readings taken in the same collection run, stored alongside every reading. Deviations are expressed as plain arithmetic (“46% above the national average”), never as judgements.
Percentile: the share of a region’s own readings in the selected window (7/30/90 days) at or below the current value. Purely positional; shown only once the region has at least 48 hours of readings in the window. A window reflects however much history currently exists for the region, capped at the stated maximum - it does not pad or extrapolate short records.
Normal range: the mean ±1 standard deviation of the metric over the window (population formula). “Above/below normal range” states where the current reading sits relative to that band - it does not assess whether the position is good or bad.
Anomaly flags (saved regions): NEW HIGH/LOW IN WINDOW - the current reading exceeds every reading in the 7-day window; RAPID CHANGE 24H - constraint frequency moved more than 20 percentage points against the reading nearest 24 hours ago; DIVERGING FROM PEERS - constraint frequency differs from the mean of the other saved regions by more than 25 percentage points. Each flag is a statement of arithmetic fact.
Every reading stores the outcome of its collection run: ok (all sources fetched), partial (some failed), or gap. Charts draw missing data as gaps - never as zeros - and values from partial runs carry a caveat. The product prefers “Data unavailable” to a stale or interpolated number.
NESO Carbon Intensity API (CC BY 4.0) · Elexon BMRS BOALF/BOD/MID (free, account) · N2EX/APX via Elexon
Gridstate presents third-party measured data. It does not provide investment advice.