{
  "generated": "2026-10-08T02:57:50.177Z",
  "licence": {
    "id": "CC-BY-4.0",
    "name": "Creative Commons Attribution 4.0",
    "url": "https://creativecommons.org/licenses/by/4.0/"
  },
  "attribution": "UK Energy Data (ukenergydata.co.uk), from the Carbon Intensity API (NESO and partners), NESO data (Supported by National Energy SO Open Data) and the Octopus Energy public API",
  "source": [
    {
      "name": "Carbon Intensity API (NESO and partners)",
      "url": "https://carbonintensity.org.uk",
      "licence": "Creative Commons Attribution 4.0",
      "licenceUrl": "https://creativecommons.org/licenses/by/4.0/",
      "credit": "Carbon Intensity API (NESO and partners)"
    },
    {
      "name": "NESO daily balancing costs and constraint breakdown",
      "url": "https://www.neso.energy/data-portal/daily-balancing-costs-balancing-services-use-system",
      "licence": "NESO Open Data Licence",
      "licenceUrl": "https://www.neso.energy/data-portal/neso-open-licence",
      "credit": "Supported by National Energy SO Open Data"
    },
    {
      "name": "Octopus Energy public API (Agile Octopus, London)",
      "url": "https://developer.octopus.energy",
      "licence": null,
      "licenceUrl": null,
      "credit": "Octopus Energy. Only monthly summary figures are given here; the half-hourly prices are not republished."
    }
  ],
  "documentation": "https://www.ukenergydata.co.uk/developers#reports",
  "data": {
    "month": "2026-09",
    "title": "State of the grid: September 2026",
    "url": "https://www.ukenergydata.co.uk/state-of-the-grid/2026-09",
    "summary": [
      "Great Britain's electricity averaged 108 grams of CO₂ per kWh in September 2026, 4% lower than in September 2025 (112 g/kWh).",
      "Wind supplied 38% of electricity, ahead of gas at 21% and nuclear at 13%. Zero-carbon sources (wind, solar, nuclear and hydro) made up 60%, and wind's share peaked at 72.8% at 04:30 on Saturday 19 September.",
      "The cleanest day was Saturday 19 September (60 g/kWh) and the dirtiest Tuesday 22 September (190 g/kWh). The cleanest single half-hour, 27 g/kWh, was at 14:00 on Saturday 12 September.",
      "Intensity was below 100 g/kWh in 50% of half-hours (48% a year earlier).",
      "Balancing the grid cost NESO £505 million. Of that, £479 million (95%) went on constraints, mostly paying generators to change output when power lines were full (£466 million), and 1,772 GWh of generation was turned down because the network could not carry it.",
      "On Agile Octopus in London, the unit price averaged 26.2p/kWh and ranged from −5.0p to 86.7p. Prices were below zero in 131 half-hours, when customers were paid to use electricity."
    ],
    "intensity": {
      "mean": 108,
      "min": {
        "value": 27,
        "from": "2026-09-12T13:00Z"
      },
      "max": {
        "value": 235,
        "from": "2026-09-28T17:00Z"
      },
      "share": {
        "wind": 38,
        "solar": 7.1,
        "nuclear": 13.1,
        "gas": 21.2,
        "imports": 8.2,
        "biomass": 8.6,
        "hydro": 1.7,
        "coal": 0,
        "other": 2.2
      },
      "zeroCarbon": 59.8,
      "peakWind": {
        "value": 72.8,
        "from": "2026-09-19T03:30Z"
      },
      "halfHoursUnder100": 713,
      "halfHours": 1440,
      "cleanestDay": {
        "date": "2026-09-19",
        "mean": 60
      },
      "dirtiestDay": {
        "date": "2026-09-22",
        "mean": 190
      },
      "days": [
        {
          "date": "2026-09-01",
          "mean": 95
        },
        {
          "date": "2026-09-02",
          "mean": 145
        },
        {
          "date": "2026-09-03",
          "mean": 73
        },
        {
          "date": "2026-09-04",
          "mean": 71
        },
        {
          "date": "2026-09-05",
          "mean": 80
        },
        {
          "date": "2026-09-06",
          "mean": 69
        },
        {
          "date": "2026-09-07",
          "mean": 83
        },
        {
          "date": "2026-09-08",
          "mean": 84
        },
        {
          "date": "2026-09-09",
          "mean": 107
        },
        {
          "date": "2026-09-10",
          "mean": 113
        },
        {
          "date": "2026-09-11",
          "mean": 129
        },
        {
          "date": "2026-09-12",
          "mean": 81
        },
        {
          "date": "2026-09-13",
          "mean": 164
        },
        {
          "date": "2026-09-14",
          "mean": 151
        },
        {
          "date": "2026-09-15",
          "mean": 78
        },
        {
          "date": "2026-09-16",
          "mean": 112
        },
        {
          "date": "2026-09-17",
          "mean": 66
        },
        {
          "date": "2026-09-18",
          "mean": 61
        },
        {
          "date": "2026-09-19",
          "mean": 60
        },
        {
          "date": "2026-09-20",
          "mean": 81
        },
        {
          "date": "2026-09-21",
          "mean": 162
        },
        {
          "date": "2026-09-22",
          "mean": 190
        },
        {
          "date": "2026-09-23",
          "mean": 130
        },
        {
          "date": "2026-09-24",
          "mean": 134
        },
        {
          "date": "2026-09-25",
          "mean": 142
        },
        {
          "date": "2026-09-26",
          "mean": 112
        },
        {
          "date": "2026-09-27",
          "mean": 83
        },
        {
          "date": "2026-09-28",
          "mean": 180
        },
        {
          "date": "2026-09-29",
          "mean": 101
        },
        {
          "date": "2026-09-30",
          "mean": 105
        }
      ]
    },
    "lastYear": {
      "month": "2025-09",
      "mean": 112,
      "share": {
        "wind": 38.6,
        "solar": 7.1,
        "nuclear": 10.8,
        "gas": 23.9,
        "imports": 11.4,
        "biomass": 8.2,
        "coal": 0,
        "other": 0
      },
      "zeroCarbon": 56.4,
      "missing": [
        "hydro"
      ]
    },
    "balancing": {
      "days": 30,
      "total": 505347351,
      "constraints": 479293593,
      "turnedDownMwh": 1772455,
      "turnedDownDays": 30,
      "thermal": 466483349
    },
    "agile": {
      "region": "C",
      "regionName": "London",
      "product": "AGILE-24-10-01",
      "mean": 26.2,
      "min": -5,
      "max": 86.7,
      "negative": 131,
      "halfHours": 1440
    }
  }
}