The insight that changes everything
There's a number that stops most people when they first hear it: the difference between electricity at 6pm and electricity at 3am on Octopus Agile is, on a typical evening, somewhere between 8 and 20 times.
Not 20% cheaper. Not twice as cheap. Twenty times.
Your tumble dryer costs 62p to run at 6pm peak (assuming 38p/kWh). That same load costs 5p at 3am when the rate drops to 3p/kWh. Run the maths across a family washing four loads a week, and that single habit shift - run everything at night - saves over £100 a year on the tumble dryer alone.
This is the insight that underlies everything in this guide. It's not about using less. It's about using it when the grid is quiet, renewable energy is abundant, and the price reflects that reality.
Why timing matters more than efficiency
You've probably heard that you should wash at 30°C instead of 60°C. Good advice - it saves about £20 a year. But shifting your washing machine from 6pm to 1am? That saves about £71 a year without touching the temperature dial.
You've probably been told to turn off standby devices. Also good - saves £10-15 a year. But running your dishwasher at midnight instead of after dinner saves £73 a year from that single appliance.
Volume reduction is one game. Timing is a completely different - and bigger - game. The best players play both. But if you're starting somewhere, start with timing.
The five appliances to shift tonight
Five appliances account for the overwhelming majority of what most UK households can save through timing. Start here. Master these. Everything else is secondary.
1. Washing machine
Typical power: 2kWh per cycle at 40°C (1kWh at 30°C).
Peak cost (38p/kWh): 76p per cycle. Overnight cost (4p/kWh): 8p per cycle.
Annual saving from shifting a daily wash to overnight: £62-70.
How to do it: Every washing machine sold since 2010 has delay start. It's almost always a button labelled "Delay" or a timer dial. Set it in the evening for a start time of 1-3am. Check AgileAlert tonight to find the cheapest 2-hour slot in your region - then dial the machine to start at the beginning of that window.
Safety note: Modern washing machines are designed to run overnight. They have automatic water leak detection and fire-safe components. Millions of UK households run their machines overnight safely. If you're worried, run the first cycle overnight while you're at home to reassure yourself - then never think about it again.
2. Tumble dryer
Typical power: 2.5kWh per cycle (condenser) or 1kWh per cycle (heat pump dryer).
Peak cost (38p/kWh): 95p per cycle. Overnight cost (4p/kWh): 10p per cycle.
Annual saving from shifting 4x weekly drying to overnight: £90-105.
How to do it: Set your tumble dryer delay start after your washing machine finishes. If your washer starts at 1am and takes 90 minutes, set the dryer to start at 3am. The whole laundry cycle runs while you sleep. Done by 5am.
Upgrade worth considering: If you have an older condenser dryer, a heat pump tumble dryer uses 60% less electricity. Combined with overnight timing, a heat pump dryer can drop your annual drying cost from £127 (peak, condenser) to under £15 (overnight, heat pump). That's a payback on the machine in under 3 years.
3. Dishwasher
Typical power: 1.2-1.8kWh per cycle.
Peak cost (38p/kWh): 57-68p per cycle. Overnight cost (4p/kWh): 5-7p per cycle.
Annual saving from shifting a daily dishwasher to overnight: £65-80.
How to do it: Load the dishwasher after dinner. Instead of pressing start, hold the delay button (labelled "Delay Start," "Timer," or shown by a clock icon on every major brand). Select 3-4 hours delay. Done. The machine runs at midnight for 6p instead of running immediately for 60p.
Also worth doing: Use Eco mode. It runs at a lower temperature with longer cycle times - not a problem at night when time is irrelevant. Eco mode cuts energy use by 20-30% further.
4. Electric vehicle charging
Typical energy: 7.4kW home charger, 8 hours = 59kWh per full charge.
Peak cost (38p/kWh): £22.40 for a full charge. Overnight cost (4p/kWh): £2.36 for a full charge.
Annual saving for 10,000-mile driver: £400-600.
How to do it: Set your EV charger to only charge between midnight and 6am, or set it via the car's own app (most EVs let you schedule charging times directly). For maximum optimisation, a smart charger like OHME or Zappi integrates directly with Octopus Agile and automatically charges during the cheapest 30-minute slots - you set the target battery level and departure time, it handles the rest.
The EV overnight charging saving is so significant - often £500+ per year - that it alone justifies switching to Agile. If you drive an electric car and you're not on Agile (or a similar time-of-use tariff), you are almost certainly leaving hundreds of pounds unclaimed every year.
5. Immersion heater / hot water cylinder
Typical power: 3kWh to heat a 150L cylinder.
Peak cost (38p/kWh): £1.14 per day. Overnight cost (4p/kWh): 12p per day.
Annual saving from shifting to overnight heating: £135-160.
How to do it: Set a timer on your immersion heater to come on at 1-2am and heat the cylinder for 90 minutes. A well-insulated cylinder will stay hot until the following evening. If you have a solar panel diverter, combine it with overnight Agile: the diverter tops up with solar during the day, the timer tops up with cheap overnight electricity if needed.
Your complete daily timing guide
| Appliance | Worst time to run | Best time to run | Annual saving |
|---|---|---|---|
| Washing machine | 5-8pm (£0.76/load) | 1-4am (£0.08/load) | £62-70 |
| Tumble dryer | 5-8pm (£0.95/load) | 2-5am (£0.10/load) | £90-105 |
| Dishwasher | 7-9pm (£0.64/cycle) | Midnight-3am (£0.06/cycle) | £65-80 |
| EV (10k miles) | 6-10pm (£22.40/charge) | Midnight-6am (£2.36/charge) | £400-600 |
| Immersion heater | Morning peak (£1.14/day) | 1-3am (£0.12/day) | £135-160 |
| Pool/hot tub pump | Any daytime (£1.20/hr) | 3-5am (£0.12/hr) | £200-400 |
What to avoid: the three expensive habits
Three common habits push up Agile bills disproportionately. Eliminate these and your savings compound quickly:
1. Running appliances at 5-8pm. The evening peak is when the price spikes most sharply. Every load you can move out of this window saves you roughly 10x its overnight equivalent.
2. Running appliances "whenever."strong> On a flat tariff, running the machine at 2pm vs 7pm makes no difference. On Agile, 2pm (typically 15-18p) vs 7pm (35-45p) is a near-doubling of cost for the same load. Timing always matters on Agile.
3. Not checking tomorrow's prices tonight. Agile prices are published at 4pm daily for the next day. Ten minutes before bed, a 30-second check of AgileAlert tells you if tomorrow has an exceptionally cheap window (say, 1-3am at 2p/kWh) or whether tonight's prices are high and it's worth waiting for a different day. The check is the whole game.
Setting delay start: a brand-by-brand guide
Washing machines
Samsung: Press "Delay End" - enter the time you want the wash to finish (not start). If your cycle is 90 minutes and you want it done by 5am, set Delay End to 05:00.
Bosch / Siemens: Turn the programme dial to your wash, then press "Start/Reload" once - it flashes a time. Press again to add hours. Long-press Start to activate.
Hotpoint / Indesit: Press and hold the "Delay" button until the LED shows hours remaining. Press repeatedly to add hours. Press Start to confirm.
LG: Use the SmartThinQ app. Set your wash time remotely from your phone. You can even check Agile prices in one browser tab and set the delay in another.
Dishwashers
Bosch: Load and select programme. Press "+" button to add delay hours. The display shows when the cycle will end. Press Start.
AEG / Electrolux: Select programme, press the clock button, use +/- to set start time. Press and hold Start.
Miele: Select programme, press "Start/Stop" once (shows "H:MM"). Use the rotor to set delay. Press Start/Stop again to confirm.
Can't find your model's delay start? Search "[brand] [model number] delay start" on YouTube. There will be a 2-minute tutorial for almost every machine ever made.
The 60-second evening routine that changes your bill
This is all you need to do every evening. It takes less time than a cup of tea:
1. Open AgileAlert on your phone. Note tonight's cheapest 2-hour window (shown in the stat bar at the top).
2. Load the washing machine. Set delay start to begin at the start of that window.
3. Stack the dishwasher. Set it to start 30 minutes after the washing machine finishes (so they don't run simultaneously on your circuit).
4. Plug in the EV if you have one. It'll charge automatically overnight.
5. That's it. Everything runs while you sleep. In the morning, everything is done, clean, and charged. You paid a fraction of peak prices.
Do this every day for a year. You'll save £150-600 depending on your appliances. You'll barely notice doing it - it becomes as automatic as locking the door before bed.
What about appliances without delay start?
Any appliance without built-in delay start can be put on a smart plug with timer scheduling. The Tapo P110 (£12), Meross MSS310 (£14), or Amazon Smart Plug (£20) all let you set daily schedules from your phone. Turn them on at 1am, off at 5am, repeat daily. Your freezer running on a defrost cycle, a dehumidifier doing overnight drying, an immersion heater without a timer - all can be scheduled for under £15.
One smart plug, properly timed, typically pays for itself within 2-4 weeks.
Seasonal notes: when to adjust your timing
Winter (Nov-Feb): Evening prices are highest - 40-60p/kWh on cold, still evenings with no wind. Be stricter about avoiding 4-8pm. Overnight windows are critical. Check AgileAlert every evening - the price difference between a good overnight and a bad one can be dramatic in winter.
Summer (May-Sep): Solar generation drives daytime prices lower. A sunny weekday afternoon might see Agile prices of 8-12p - almost as cheap as overnight. This is a good time to run appliances during the day if overnight timing is inconvenient for your household.
Plunge pricing events (year-round): 5-10 times per month, usually on windy or low-demand days, prices go negative. Run everything you possibly can during these windows. AgileAlert shows upcoming plunge events in the Live Prices tab.