Run it at low tide.
Britain's electricity gets cleaner and dirtier every few hours as the wind rises and falls. Pick a machine you're about to run. Grid Tide reads the next 48 hours of the grid's carbon forecast and finds the cleanest time to run it, before you need it done.
The sea is the grid's carbon: high water is dirty, low water is clean. Drag the boat to try any start time.
Tide table for your machines
Every machine, same forecast, each with its own run length and deadline.
Does waiting really help?
We replayed a whole year of Britain's grid, . Each evening a dishwasher could start at 7 pm. Grid Tide picked a start from the forecast, and both runs were scored on the grid's recorded intensity, NESO's after-the-fact estimate.
Your year
Tick what you own and how often you run it. Savings use the replay above, not tonight's forecast.
How it works
The forecast
National Energy System Operator's Carbon Intensity API publishes grams of CO2 per kWh for every half-hour of the next 48 hours, for Great Britain, its three nations and 14 regions, with the generation mix behind it. Grid Tide fetches it straight from your browser. No account, no tracking; your settings stay in your browser.
The pick
For a machine that runs for n half-hours, every possible start between now and your deadline is scored by its average carbon over the whole run. The cleanest wins; ties go to the earliest start so you wait no longer than needed. CO2 per run is energy times that average.
What it misses
The forecast is the grid's average intensity. What a shifted load truly avoids depends on the power station that ramps up or down for it, usually gas at peak and, on windy nights, wind that would otherwise be curtailed, so treat the grams as an estimate. Live data covers Great Britain only. Machine figures are typical values; type in the ones on your energy label.