Is electricity cheaper at night in the UK? Economy 7 explained

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last updated 20 January 2023

Cheaper electricity at night is made possible by Economy 7 meters.

But be warned, it can be dangerous to run appliances without supervision overnight and if you get your timings wrong it could cost you money too.

Setting your alarm and getting up in the middle of the night to run your dishwasher, washing machine or tumble dryer might sound drastic but cash-strapped households need ways to save on energy bills right now.

While Economy 7 households are still protected by the energy price guarantee – Ofgem has increased the price companies can charge customers which means suppliers could be putting up prices this month.

According to the BBC - around 2.5 million households could see an average annual rise of over £100 on their Economy 7 bills with prices up by an average of 7.6% this year.

Despite this increase, Ofgem says Economy 7 households pay, “lower average electricity rates than single rate customers, but use more electricity”.

Ofgem estimates that a typical Economy 7 customer uses 4,200kwh per year compared with 2900kwh for single-rate customers.

Despite this, it says overall annual costs are lower if Economy 7 is used correctly. This means 58% of electricity is used during the day and 42% during ‘off peak’ times.

Here we explain how you can unlock cheaper energy at night - and the risks.

Is electricity cheaper at night? - Economy 7 explained

With standard electric meters - you pay the same price for each unit of energy (kWh) you use regardless of the time of day or night.

But if you have an Economy 7 meter - typically installed in houses reliant on electricity for both heating and hot water instead of gas - can help you save on your electricity bill because it unlocks cheaper overnight rates.

Under the energy price guarantee – which kicked in on 1 October – you pay 34p per unit (kWh) of electricity-based payment by direct debit. But in some cases Economy 7 could be around 10p per unit cheaper with nighttime rates.

Kevin Mountford, co-founder of savings platform Raisin UK, says: “If you work night shifts or find yourself sleeping during the day and then doing chores at night, this tariff will save you money. It’s also ideal for electric car owners who will charge their electric cars in the evening”.

How Economy 7 energy works

With Economy 7 - you pay two different rates for the electricity you use – one during the day and a cheaper one for an overnight period of seven hours.

“Some Economy 7 plans charge a significant amount over the standard night rate for any electricity used in the day, which can cancel out the benefits of the cheap electricity you get at night”, says Ben Gallizzi, energy expert with Uswitch.

“As a general rule of thumb, you would need to use more than 40% of your electricity at night to make Economy 7 cost-effective”.

There’s no universal fixed time when the cheaper overnight rates kick in according to Uswitch, and it can depend on your supplier along with where you live.

Generally, the cheaper ‘night’ rate can run from 11 pm – 6 am or midnight to 7 am or 1 am to 8 am.

“It’s important to check with your energy supplier to work out what the Economy 7 hours are, as if you use electricity out of the 7-hour window, you will be paying more”, warns Kevin Mountford.

It is also worth knowing Economy 7 meters won’t adjust automatically when the clocks go forwards or back. So check what you need to do with your supplier as the clocks go back one hour on 30 October at the end of British Summer Time.

But be warned - it can be dangerous to run some appliances overnight

It might be cheaper to run appliances overnight if you’ve got Economy 7 – but experts warn that you need to consider the safety element of doing this while you’re tucked up in bed.

Emily Seymour, Which? Energy and Sustainability Editor said: "Major appliances such as washing machines and dishwashers should not be used when you're asleep, or out of the house. Anything with a high wattage or a motor runs a fire risk and should not be left unattended”.

And Ben Gallizzi says, “Leaving appliances running overnight means you are less likely to know when something goes wrong like if they catch fire. This is why firefighters advise people to turn off what they can overnight”.

Can you always save money with Economy 7?

There’s no guarantee you’ll automatically save money as reduced energy bills will depend on your habits and on the flip side – the cost per unit can be more expensive during the daytime.

Kevin Mountford, co-founder of the savings platform Raisin UK, said: “With Octopus Energy some customers have reported seeing their tariffs increase by as much as 8%. Based on an Octopus Energy economy 7 tariff, the day rate for electricity is 43.47p per kWh, whilst the night rate is 18.06p per kWh. The average washing machine is 2,100 watts, which is equal to 2.1 kWh, meaning it would cost 91p per cycle to wash during the day, whilst washing during the night would only cost you 37p.”

Based on these calculations – running your washing three times a week at night instead of during the day could save you over £84 a year.

If you want to benefit from cheaper overnight rates with Economy 7 - but don’t want to wait up to start your washing at 11 pm or later – the easy option is to buy a plug-in timer.

This means you can pre-set appliances to come on at fixed times and you can pick these up from around £6.99 at Screwfix or buy a set of three at Argos for £12.99.

Can you save money using appliances ‘off peak’ if you’re not on Economy 7?

Octopus Energy is running a flexible energy service for domestic customers on smart meters along with 5,000 businesses that can get paid if they reduce their energy usage at certain peak times.

Saving Sessions means for each unit of energy saved, compared to normal usage - Octopus will pay an average of £4 per kilowatt hour.

This could save customers around £100 over the course of the Winter from November to next March.

Sue Hayward is a personal finance and consumer journalist, broadcaster and author who regularly chats on TV and Radio on ways to get more power for your pound. Sue’s written for a wide range of publications including the Guardian, i Paper, Good Housekeeping, Lovemoney and My Weekly. Cats, cheese and travel are Sue’s passions away from her desk!