Carbon Intensity UK — Free UK Electricity Grid Carbon API (No Key)

TL;DR

The Carbon Intensity API from the National Grid ESO provides real-time and forecast data on the carbon intensity of electricity generation in the UK. It returns the current carbon footprint (in gCO2/kWh) of the national grid, broken down by fuel type (gas, coal, wind, solar, nuclear, etc.). The API also provides 48-hour forecasts and regional data for 13 UK regions. No authentication needed. Essential for building energy-aware applications that can schedule tasks when the grid is greenest.

Quick start: https://api.carbonintensity.org.uk/intensity/date

No API key needed — just make a request!

How to Use This API

1. Current Carbon Intensity

https://api.carbonintensity.org.uk/intensity

2. Today's Intensity (Half-Hourly Data)

https://api.carbonintensity.org.uk/intensity/date

3. 48-Hour Forecast

https://api.carbonintensity.org.uk/intensity/2026-06-15/2026-06-17

4. JavaScript — Get Current Carbon Level

fetch('https://api.carbonintensity.org.uk/intensity')
  .then(r => r.json())
  .then(data => {
    const now = data.data[0];
    console.log(`Current intensity: ${now.intensity.actual} gCO2/kWh`);
    console.log(`Classification: ${now.intensity.classification}`);
    // Classifications: very low, low, moderate, high, very high
  });

5. Python — Find Optimal Charging Time

import requests
from datetime import datetime, timedelta

start = datetime.now().strftime('%Y-%m-%dT%H:%MZ')
end = (datetime.now() + timedelta(hours=24)).strftime('%Y-%m-%dT%H:%MZ')

data = requests.get(
    f'https://api.carbonintensity.org.uk/intensity/{start}/{end}'
).json()

# Find the lowest intensity period
periods = data['data']
best = min(periods, key=lambda p: p['intensity']['forecast'])
print(f"Best time to charge: {best['from']}")
print(f"Forecast intensity: {best['intensity']['forecast']} gCO2/kWh")

Today's intensity: https://api.carbonintensity.org.uk/intensity/date

Try This URL Now

Frequently Asked Questions

What do the intensity classifications mean?: Classification levels: very low (0-50 gCO2/kWh), low (50-150), moderate (150-250), high (250-350), and very high (350+).
Can I get data by UK region?: Yes. Use /regional endpoints like https://api.carbonintensity.org.uk/regional for current regional data. There are 13 regions including North Scotland, South Wales, London, and more.
How often is the data updated?: Carbon intensity data is updated every 30 minutes, reflecting actual grid conditions. Forecast data is updated every 2 hours for the 48-hour outlook.
What fuel mix data is available?: The generation mix endpoint (/generation) breaks down electricity generation by fuel type: gas, coal, nuclear, wind, solar, hydro, biomass, French interconnector, and Dutch interconnector.
What date format does the API use?: Dates use ISO 8601 format: YYYY-MM-DD for dates and YYYY-MM-DDTHH:MMZ for date-time range queries. All times are in UTC.
Is the API free for commercial use?: Yes, the Carbon Intensity API is provided by National Grid ESO as open data. Free for any use including commercial applications.

API Details

API URL: https://api.carbonintensity.org.uk
Documentation: carbonintensity.org.uk
Category: Science
Authentication: Not Required
Geographic Coverage: United Kingdom (UK) — National Grid and 13 regions

What You Can Build

Smart EV charger that schedules charging when grid carbon is lowest
Home energy dashboard showing real-time grid carbon status
Smart appliance scheduler that runs dishwashers during green periods
Carbon-aware CI/CD pipeline that delays builds to low-carbon times
Environmental education display showing fuel mix and carbon trends