Best Time to Use Electricity UK
Live carbon intensity data to help you save money and reduce your environmental impact
What is Carbon Intensity?
Carbon intensity measures how much CO₂ is emitted for each unit of electricity generated (gCO₂/kWh). When the grid uses more renewable energy like wind and solar, carbon intensity drops. When demand is high and gas plants fire up, it rises.
Why does it matter? By timing your energy use to periods of low carbon intensity, you can reduce your carbon footprint and potentially save money. Many energy tariffs now offer cheaper rates during off-peak hours when renewables dominate the grid.
How to use this tool: Select your region below to see real-time carbon intensity data. Green means the grid is clean — great for running appliances, charging EVs, or using your immersion heater. Red means carbon is high — consider delaying heavy electricity use.
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London
Region 13
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Octopus Agile + Carbon
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Used only to estimate your regional tariff pricing.
Privacy note: Your postcode is stored locally and only used to fetch regional pricing.
Carbon = clean. Low gCO₂/kWh means greener electricity.Agile price = cheap. Low p/kWh saves money. The best window combines both for optimal timing.
Want to plan a specific appliance?
Use the Agile Savings Planner to calculate the cheapest window for EV charging, dishwashers, washing machines, immersion heaters and more.
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Live carbon and price data help you decide when to use energy. EPC data helps you understand why your home uses energy in the first place.
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Real-World Context
UK grid carbon intensity has dropped 70% since 2012
The UK electricity grid has become dramatically cleaner over the past decade, with wind and solar now regularly providing over 50% of electricity on optimal days. However, carbon intensity still varies significantly throughout each day — from under 50 gCO₂/kWh during windy afternoons to over 300 gCO₂/kWh during calm winter evenings when gas plants dominate. This variation creates opportunities to reduce both your carbon footprint and energy costs by timing high-consumption activities.
Source: National Grid ESO Carbon Intensity API, Real-time data
Why Carbon Intensity Data Matters For Your Wallet
- Low carbon often means low price — when wind and solar dominate, wholesale electricity prices drop, which is reflected in time-of-use tariffs like Octopus Agile
- EV charging optimisation — charging during low-carbon periods can reduce costs by 50% compared to peak evening rates
- Heat pump efficiency — running your heat pump when grid intensity is low maximises environmental benefits without compromising comfort
- Battery storage arbitrage — home batteries can charge during cheap green periods and discharge during expensive peak times
How To Use This Data
If carbon intensity is below 100 (Green):
This is the optimal time to run high-energy appliances — washing machines, dishwashers, tumble dryers. If you have an EV, start charging now. Heat pumps can pre-heat your home efficiently.
If carbon intensity is 100–200 (Amber):
Normal usage is fine, but consider delaying large loads if you expect intensity to drop. Check the best times guide for typical daily patterns.
If carbon intensity is above 200 (Red):
Avoid running high-consumption appliances if possible. This typically occurs during calm winter evenings. Focus on reducing heat loss instead.
If you're unsure what to do:
Click "What should I do right now" above for personalised recommendations based on current conditions and your region.
About This Tool
This live carbon intensity tool uses official data from the National Grid ESO Carbon Intensity API — the same data used by energy suppliers, grid operators, and government agencies. Data is refreshed every 30 minutes for all 14 UK distribution regions.
- Official National Grid ESO data source
- Regional breakdown for all 14 UK grid zones
- Real-time generation mix including wind, solar, nuclear, and gas
Data updates: Every 30 minutes from National Grid ESO
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