Monthly snapshot
January 2026 recorded an average grid carbon intensity of 145g CO2/kWh across 1488 half-hour periods. The cleanest period in the month reached 42g CO2/kWh, while the highest period reached 286g CO2/kWh.
Renewable output stayed just under half of measured generation on average. The recorded renewable share was 48.5%. The month was more carbon-intensive than the strongest renewable months in the archive. These figures make the month useful as a benchmark for comparing live dashboard conditions with a completed calendar month.
Generation mix
Wind was the largest source in the monthly mix at 39.8%. Gas followed at 32.5%. Gas averaged 32.5%, nuclear averaged 10.8%, and imports averaged 8.2%.
Wind averaged 39.8% and solar averaged 1.5%, leaving the renewable share below the halfway mark. That usually means gas, imports or nuclear availability had a larger role in setting the monthly carbon range. The live dashboard can still show very clean periods inside a month like this when wind or solar conditions line up.
The mix shown here is an average of the published generation percentages for the month. It is intended for month-to-month comparison rather than billing, settlement, or operational decision-making.
Carbon range
The gap between the cleanest and highest-carbon periods was 244g CO2/kWh. That wide range shows why a monthly average should be read alongside the live half-hour view. Short clean windows can sit inside a month that still has a much higher average when demand rises or fossil generation increases.
Coverage and comparison
The report covers 1488 half-hour periods, roughly 31 complete days of public grid readings. Using every available settlement period avoids cherry-picking individual clean or dirty moments. It also makes the monthly page useful for comparing one completed month with another as the report archive grows.
For a quick comparison, watch how gas at 32.5%, imports at 8.2% and nuclear at 10.8% line up against the renewable share. Those three figures often explain why two months with similar wind or solar output can still have different carbon averages. Higher nuclear output can steady the low-carbon base. Higher gas output usually lifts the monthly average, especially when demand is high, renewable output is weaker, or evening peaks are sharper across several consecutive days.
How to read this report
A lower carbon intensity means each unit of electricity consumed caused fewer grams of carbon dioxide equivalent. Renewable percentage measures the share from wind, solar, hydro and biomass in the published generation mix. The figures move with weather, demand, plant availability, imports and market conditions.
Use this page alongside the live dashboard when you want context for current conditions. A live 90g CO2/kWh reading means something different after a low-carbon month than it does during a gas-heavy winter stretch.
Methodology
This report is generated from structured monthly data used by UK Grid Live. Carbon values are summarised from the Carbon Intensity API. Generation mix percentages are averaged from the published monthly mix values used in the reports archive. Source details and caveats are documented on the methodology page.