Latest available carbon intensity value.
UK carbon intensity is the amount of CO₂ emitted per kilowatt hour of electricity, measured in grams of CO₂ per kWh (gCO₂/kWh).
What Carbon Intensity Means
Carbon intensity provides a straightforward answer to the question: how clean is the electricity right now?
It measures the emissions produced for each unit of electricity, typically shown as grams of CO₂ per kilowatt hour (gCO₂/kWh). A lower number indicates cleaner electricity, while a higher number suggests a greater reliance on fossil fuels.
It’s one of the quickest ways to understand the environmental impact of the electricity system at any given moment.
Live carbon context: a lower carbon number usually means low-carbon generation is carrying more of the grid. A higher number usually means gas or higher-carbon imports are doing more of the work.
What affects carbon intensity?
WindLowers CO₂
Strong wind output often has the biggest impact on cleaner periods.
GasRaises CO₂
Gas is flexible, but it usually increases carbon intensity.
SolarDaytime help
Solar can reduce emissions during daylight, especially in spring and summer.
ImportsDepends
Imported electricity can be clean or carbon-heavy depending on its source.
Why it changes
Carbon intensity isn’t fixed. It fluctuates constantly because the energy mix is always changing.
Low-carbon sources like wind, solar, nuclear, and hydro lower the number. Gas increases it. Coal, which is now rare in the UK, would push it up even more.
Imports also matter because electricity from other countries reflects their energy mix, not just the UK's.
So, the number you see is really a snapshot of everything happening on the grid at that moment.
Patterns through the day
Like demand, carbon intensity follows patterns, but they aren’t always clear.
A windy afternoon can have very low carbon intensity, even if demand is normal. A cold, still evening might be much higher because the system needs more gas to keep up.
Solar reduces the number during the day, especially in spring and summer, but disappears completely after sunset.
That’s why live data matters—the grid can look very different from one hour to the next.
Live carbon intensity is a snapshot
Two days with the same demand can have very different carbon intensity values. The difference is usually the mix of wind, solar, nuclear, imports and gas at that moment.
Use the chart as a cleanliness trend
A falling line usually means cleaner power is taking a larger share. A rising line normally means the grid is leaning more heavily on higher-carbon sources.
Most useful companion views
Wind
Gas
Demand
UK carbon intensity — last 24 hours
Recent carbon intensity in gCO₂/kWh.
This chart shows how UK carbon intensity has changed over the past 24 hours, making it easier to compare the current value with recent conditions.
Cleaner than normal
When wind, nuclear, solar and hydro cover a larger share of demand, the grid can run with much lower emissions.
Higher-carbon periods
When demand rises and renewable output falls, gas generation often fills the gap and the carbon number moves higher.
What makes it low (or high)
- renewable output (especially wind) is strong
- demand is manageable
- fossil fuel use is low
In the UK, wind is often the biggest factor. When it generates well, it can supply a large portion of demand and significantly lower carbon intensity.
Nuclear provides a steady low-carbon base, while solar adds a daytime boost.
Higher-carbon periods usually happen when demand is high and renewable output is low. Gas-fired power stations are flexible and fill that gap, but they produce higher emissions.
Why it matters
Carbon intensity isn’t just an interesting number; it can actually be useful.
If you can adjust when you use electricity—like charging an EV, running appliances, or heating water—you can sometimes shift that usage to cleaner periods.
It may not always align with the cheapest times, but it can reduce your overall impact.
More broadly, it also shows how the grid is changing. As more renewable and low-carbon sources are added, the system should spend more time at lower intensity levels, but there will still be moments when fossil fuels are necessary.
On this page
The chart here shows how carbon intensity has changed over the last 24 hours, allowing you to compare current conditions to recent trends.
To understand why it’s high or low, it’s best viewed alongside demand, generation, and imports—either through the links on this page or by returning to the main dashboard.
Return to the live UK electricity dashboard
Page freshness signal: Live — Updated within the live window. Latest row Thu, 21 May 2026 19:15 BST.
FAQ
Quick answers about this page and the live data.
What is a good carbon intensity value?
Lower is better. Very low values usually happen when wind, solar, nuclear and other low-carbon sources dominate the mix.
Why does gas increase carbon intensity?
Gas generation burns fossil fuel, so each kilowatt hour produced has much higher operational emissions than wind, solar, nuclear or hydro.
Can carbon intensity change quickly?
Yes. Weather, demand, generator availability and imports can all change the generation mix within hours.
How do I see what is causing the current value?
Use the generation mix page or homepage to see which sources are producing electricity right now.