When is electricity cheapest? How to use cheap slots
On a half-hourly tariff the cheapest time to use electricity changes every day. These steps help you find it and use it without much effort.
When electricity is usually cheapest
Prices are often lowest overnight, and on some days in the middle of the day when wind and solar output is high. They are usually highest in the early evening, roughly 4pm to 7pm. These are patterns, not rules: check each day’s published rates.
1. Check the next day’s rates once they are published
Dynamic tariffs usually publish the next day’s half-hourly rates once a day, in the afternoon. That is a good moment to plan the evening and the following day.
2. Work out how long each job takes
A wash cycle might take two hours; topping up an electric car might take four. List the jobs that can move and how long each one runs.
3. Pick the cheapest window, not the cheapest half hour
For each job, find the run of half hours of that length with the lowest average price. A single very cheap half hour does not help much if the job runs on into dearer ones.
4. Schedule it
- Use the delay-start timer on your washing machine or dishwasher.
- Set a charging schedule in your electric car’s or charger’s app.
- Schedule home batteries, hot water and heat pumps where they allow it.
- Use smart plugs only with appliances that are designed to be switched on and off at the socket.
5. Move what you can out of the evening peak
Even shifting a few flexible jobs from the early evening to later at night can make a difference. Don’t move things that would make your day harder; the aim is the easy wins.
Stay safe
UK fire services advise against leaving washing machines, tumble dryers and dishwashers running overnight or while you are out. Where you can, time them to finish while you are at home and awake, and follow the manufacturer’s instructions.
When prices go below zero
Occasionally prices fall below zero. That is a good time to charge a car or a home battery, or run jobs you would do anyway. It is not a reason to waste energy.
What to expect
How much you save depends on your tariff, how much you can move and the prices on the day. Savings are not guaranteed, so compare your costs with your previous tariff from time to time. To understand the prices themselves, read half-hourly electricity prices explained and what an Agile-style tariff is.
Plan with the day’s rates on your iPhone
Octomiser shows the current half-hourly rate and the rates still to come, finds the cheapest window for the time you need and keeps live rates in Home and Lock Screen widgets. Today it works with Octopus Energy accounts in the UK, including the Agile tariff.
Download on the App Store