What's powering Britain right now
Loading the latest grid data…
Live data unavailable — retrying shortly.
Loading generation mix data.
Live data unavailable — retrying shortly.
Loading today's intensity data.
Live data unavailable — retrying shortly.
Greenest window today
—
—
Loading regional data.
Tap a region to see its details.
Regional data unavailable — retrying shortly.
Loading historical data.
Historical data unavailable — retrying shortly.
Walk around your home and list every electrical device you can find. Sort each one into high, medium, or low energy use — then check how you did.
Check your answers →Pick any household appliance, enter how many hours it's used, and get a live estimate of the energy cost and carbon footprint — based on what's actually powering the grid right now.
Open calculator →A plain-English glossary of the energy and climate words used across this site — from kWh and carbon intensity to net zero, biodiversity and the 5 Rs.
Open glossary →Trying again in 30 seconds.
Carbon intensity is a measure of how much CO2 is released for every unit of electricity generated — expressed in grams of CO2 per kilowatt-hour (gCO2/kWh). When the grid runs on wind, solar, hydro and nuclear, intensity is low. When gas and coal pick up the slack, it rises.
The figures shown here come from the National Grid ESO Carbon Intensity API, which is updated every 30 minutes and includes forecasts for the next 48 hours.
Why time-shifting matters. If you can run heavy appliances — dishwasher, washing machine, EV charger — during the greenest window of the day, the same task produces less CO2. The grid does the cleaning; you choose when.
The band thresholds (very low, low, moderate, high, very high) come from the API itself and are updated by National Grid ESO as the grid decarbonises over time.