Roast when the grid is greenest.
Our Bellwether roaster runs on electricity — so its footprint rises and falls with the grid. NESO — the National Energy System Operator — publishes live carbon data every half hour, and we use it to time our roasts for the windows when Britain is running on the most wind, solar and nuclear.
27%
zero-carbon
generation
Wind, solar, hydro & nuclear combined
166
gCO₂/kWh
Moderate
intensity band
22%
renewables
Right now is a fair time to roast.
About 27% of Britain's electricity is zero-carbon — not bad, but not the cleanest the grid gets. When the schedule allows, we'll hold on for a greener window.
Very clean
Clean
Average
Dirty
Very dirty
The live generation mix
Every half hour NESO reports exactly which sources are keeping the lights on. When the yellow dominates, it's a good time to roast.
The greenest windows to roast
NESO forecasts carbon intensity two days ahead. Here's how the next 48 hours are shaping up — the yellow bars are the windows we aim for.
Tomorrow, 6:00am–10:00am
low carbon
47
gCO₂/kWh avg
Tomorrow, 10:30am–5:00pm
low carbon
73
gCO₂/kWh avg
Tuesday, 9:00am–5:00pm
low carbon
60
gCO₂/kWh avg
How it works
No offsets, no hand-waving. Just electric roasting timed around real grid data.
Watch the grid
We pull NESO’s live carbon intensity and generation mix — the same open data shown on this page.
Schedule the roast
Where the schedule allows, we line up batches for the forecast windows when the grid is heaviest on wind, solar and nuclear.
Roast electric
Our ventless Bellwether roaster runs on electricity, so a greener grid means a genuinely lower-carbon roast — not a purchased claim.
Next: the grid reading, printed on the bag
We're working towards capturing the exact grid reading at the moment each batch is roasted, and printing it on the label — so the claim on the bag is something you can actually verify, not marketing gloss.
This is a planned feature rather than a promise today. When it lands, each bag will link back to its own reading on this page.
Grid at roast
Roasted 14 July, 11am —
grid was 87% zero-carbon.
Illustrative example · verify at kwhcoffee.com/grid
A greener cup for greener offices
If your workplace cares about its ESG footprint, electric roasting timed to the grid is a story worth serving. Let's talk wholesale.
Grid data from the NESO Carbon Intensity API, updated every 30 minutes. “Zero-carbon” combines wind, solar, hydro and nuclear generation. Times shown in UK time.