Cheapest time to charge your electric car
Tell us about your car and when you need it. We'll find the cheapest - or the greenest - time to charge on Octopus Agile in London, up to three days ahead, and tell you exactly what to set.
Start Saturday 12:00 · 5 hours at 32 A · 7.4 kW
30% → 80% · adds 30.0 kWh, about 105 miles (33.3 kWh from the grid) · ready by Sun 07:00
Emits about 1.1 kg CO₂ (34 g/kWh).
Prices until Sun 07:00
p/kWh as Octopus charges it, half-hourly. Octopus has published prices up to Sat 23:00; after that the bars are estimates.
How this works
Agile prices change every half hour. Octopus publishes each day's prices at around 4pm the day before, so from late afternoon every price until the next morning is known and the plan is exact. Beyond that, the bars are estimates: the latest published day's prices at the same times, moved up or down for the forecast change in wind across Great Britain - more wind generally means cheaper electricity.
Estimates are only a guide - typically within about 5p/kWh of the real half-hourly price - but they're good at the question that matters most: which night will be cheaper. Tested against a year of real prices, plans with a deadline two mornings away cost about 0.4p/kWh more than perfect hindsight, and three mornings away about 0.9p/kWh more - against about 3p/kWh more if you only ever used the prices already published. So it's worth checking back once new prices are out.
Choose lowest carbon to charge when the grid in your region is cleanest instead, using NESO's regional carbon intensity forecast, which looks about two days ahead. The cleanest hours are usually cheap too - wind drives both - but not always, so the plan shows its cost either way, and its emissions when you plan for cost.
Costs are for the electricity only, at the prices Octopus charges (with any VAT - currently 0% on household electricity) and 90% charging efficiency; your standing charge doesn't change with when you charge. A car timer charges in one unbroken block; a smart charger can pick the cheapest individual half-hours, which usually saves a little more.
Prices from the Octopus Energy API. Carbon intensity from the Carbon Intensity API by NESO, licensed under CC BY 4.0. Wind forecast from weather data by Open-Meteo.com (CC BY 4.0). Renewably isn't affiliated with any of them.