Is electricity cheaper at night and what counts as peak and off peak use?

Wondering is electricity cheaper at night? There’s a lot of confusing advice around about this subject, but our energy expert sets the record straight

a women looking into an electric washing machine at night

Is electricity cheaper at night is a tricky question to answer as it all depends what type of energy tariff you’re on. 

Energy bills are a hot topic at the moment. Households are now receiving the government’s £400 energy rebate (opens in new tab) but, with temperatures dropping, many families will still be worried about how much their energy bills will cost (opens in new tab)

Go.Compare's energy expert Gareth Kloet (opens in new tab) says: “For some consumers, energy can cost less at night. This is because suppliers sometimes charge you a cheaper rate in off-peak periods, which typically fall overnight – when the majority of people are sleeping and therefore using less energy. But, you need to be on the right tariff”

Is electricity cheaper at night?

Whether electricity is cheaper at night depends on the type of tariff you are on. Most people are on standard energy tariffs which charge the same rate for electricity whatever time of day you use it. In these cases electricity is not cheaper at night. 

But there are some tariffs that do offer cheaper electricity at night. These ‘time of use’ tariffs will usually be called Economy 7 (E7) or Economy 10 (E10). The number relates to the number of cheaper hours each day. 

Some electric vehicle (EV) tariffs also offer cheaper electricity at night. 

If you have a ‘time of use’ electricity tariff, it will operate on-peak and off-peak times, with cheaper rates charged at night. 

There are also a couple of energy suppliers running trials which encourage households to use electricity at night and give them a discount on their bill for doing so.

But the majority of energy tariffs charge a flat rate for electricity, regardless of what time of day you use it. So, if you're putting your washing machine on a night to save a few pennies, we're sorry to say it might not be making much of a difference. 

When is off peak for electricity?

With Economy 7, off-peak is usually between 12am and 7am. But what counts as peak and off-peak can vary depending on your provider, where you live, and the time of year. Make sure you check you bill or speak to your provider to find out what is classed as off-peak for your specific circumstances. 

Economy 10 tariffs tend to be more complicated as the off-peak hours are grouped throughout the day and night.

Here's an example of what Economy 10 off-peak times could be:

  •  Three off-peak hours in the afternoon (e.g. 1pm -4pm) 
  •  Two off-peak hours in the evening (e.g. 8pm – 10pm) 
  •  Five off-peak hours overnight (e.g. 12am – 5am) 

To use an Economy 7 or Economy 10 tariff you’ll need a two-rate electricity meter. These meters are capable of recording how much electricity you use at different times of the day and will allow your supplier to potentially charge you a cheaper rate in off-peak periods.

Ava Kelly, energy saving expert at Love Energy Savings (opens in new tab), says: "Off peak tariffs provide a great opportunity to make savings on your energy bills, and thanks to modern technology, there are ways that you can control devices in your home to ensure the running costs are kept to an absolute minimum.  

“By using delayed timers on appliances such as washing machines, tumble dryers, and dishwashers, you can cut the cost of running those appliances by ensuring they start up during off peak hours.  

“With regards to charging an electric car for example, ensuring you plug in after 10pm will mean you're saving on the cost. Get into the habit of ensuring you're running devices at the cheapest times and you'll see a big impact on your energy bill. Off-peak tariffs are particularly useful for those who charge an electric vehicle at night or have storage heaters.”

Potential issues with off-peak tariffs

It might sound great but there are several potential issues with Economy 7 or Economy 10 tariffs. The main one is that electricity costs in ‘peak’ hours can be very high, so if you’re not careful you’ll get a high bill overall. You’ll also need to be very organised when it comes to using appliances such as washing machines and dishwashers at night.

If you aren't on a tariff where you can benefit from cheaper energy at night, it's worth knowing how to save energy in your home (opens in new tab) to see if you can make savings by reducing your usage. 

When is peak time for electricity?

Peak time for electricity demand or use is from 4pm to 7pm. This tends to be when people get home from work, cook their dinner and do their washing. In the winter, households will also put lights and heating on around this time.

The National Grid is the system operator of Great Britain’s electricity and gas supply. It’s more expensive for the National Grid to supply electricity in periods of peak demand – energy will be cheaper overall if we can smooth out the peaks and troughs in demand.

The National Grid is trying to do this with a new Demand Flexibility Service which will give households money off their energy bills if they cut their use at peak times.

Customers taking part will be given 24 hours' notice of a "test" day where they will be asked to reduce their peak-time electricity use during a one-hour period identified by National Grid. This is likely to be between 4pm and 7pm.

The National Grid is already running trial schemes with Octopus Energy and Ovo Energy to encourage customers to use electricity at off-peak times, with customers given money off their bills if they reduce their usage at certain times of day. 

Why is it cheaper to use electricity off-peak?

The reason electricity is cheaper off-peak comes down to supply and demand. The UK’s energy supply can run more efficiently, and cheaply, if we lower energy demand during peak periods and use more in off-peak periods. Energy firms offer time of use electricity tariffs because the cost of wholesale energy varies with the time of day due to changes in demand.

Electricity demand can sometimes outstrip supply during peak periods – i.e. during the day. Typically, gas or diesel-powered plants are fired up to meet that demand. This adds to the UK’s carbon dioxide emissions and costs both the National Grid and energy suppliers money.

Do I need to be on a particular tariff to benefit from off-peak prices?

Unless you are taking part in the National Grid scheme or the schemes offered by Octopus or Ovo, you’ll need to be on a ‘time of use’ tariff (usually Economy 7 or Economy 10) to get cheaper electricity at night. Most people aren’t on these tariffs and so pay a flat rate for electricity. 

According to the energy regulator, Ofgem, about four million out of a total of 29 million domestic electricity customers in the UK are on E7 or E10 tariffs. You might have these electricity meters if you use storage heaters to heat your home and a hot water tank for hot water. The heaters and water heat up overnight for use during the day.

However, this is an expensive way to heat your home as peak rates on E7 or E10 can be much higher than standard rates on normal energy tariffs. As a result, some energy suppliers have stopped offering E7 and E10 deals. 

Time of use tariffs

There are also a small number of more modern time-of-use tariffs that work with standard electricity meters and gas-fuelled heating and hot water. 

A Uswitch spokesperson said: “Some suppliers have also started to offer time-of-use tariffs, where households can enjoy cheaper rates by shifting their energy use outside of peak times. 

“Time-of-use tariffs help to reduce demand on the National Grid, meaning there is less chance of supply shortages. They also cut down reliance on gas or diesel-powered plants — which need to be fired up to meet demand — and mean we can make more use of renewable energy.”

Green Energy UK launched its Tide tariff in 2017. Tide works in conjunction with a smart meter (opens in new tab) and offers cheaper electricity rates between 12am and 7am every day. Households on the Tide tariff who avoid using electricity between 4pm and 8pm on weekdays can also lower their bills. However, Green Energy UK is not accepting new customers at the moment. 

Another option is Octopus Energy’s Agile (opens in new tab) tariff which offers access to half-hourly energy prices, tied to wholesale prices and updated daily. ‘Plunge Pricing’ alerts customers to cheap rates and enables connected smart devices to come on when electricity is cheapest.

Octopus says the tariff is “perfect for electric vehicles, storage heaters, or anyone who can shift their electricity use outside of peak times." However, sign-ups are paused at the moment due to volatility in the energy market. 

Specialist electric vehicle (EV) energy tariffs also offer cheaper electricity at night in a bid to encourage drivers to charge their cars overnight. However, many energy providers have withdrawn their EV tariffs due to the energy crisis. For example, British Gas’ EV tariff offers cheaper electricity between 12am and 5am, but it’s not on sale at the moment.

Is it safe to run appliances at night?

The London Fire Brigade advises against leaving washing machines, tumble dryers, or dishwashers on overnight and unattended. Electrical Safety First’s position is one of mitigating risk. It says people should ensure appliances are registered with the manufacturer in case there is a product recall. Appliances should be kept in good working condition, any filters cleaned regularly, and extension leads not overloaded. It also urges households to fit working smoke alarms on every floor of their property.

Martyn Allen (opens in new tab), technical director for Electrical Safety First, says: “Where practically possible we advise everyone to avoid leaving appliances like washing machines, tumble dryers or dishwashers running unattended overnight. But we fully understand it is inevitable that those who are struggling to pay for energy will have little choice but to opt for running large appliances during cheaper tariff times.” 

Is an off-peak tariff a good idea?

Amid the current energy crisis, probably not. E7 or E10 tariffs are usually more expensive than standard tariffs, and most suppliers have withdrawn their E7/E10 deals anyway. If you have E7/E10 and find it expensive, you can ask your supplier to change you to a single-rate meter and tariff.

If you are on a more modern time of use tariff, such as offered by Green Energy or Octopus, you should compare deals with standard tariffs.

Most households would be better off on a standard variable tariff at the moment.

Not every household will suit a time of use tariff even if energy prices fall. For example, if you work from home, you’ll need to run your computer during the day. If you own an electric vehicle, it might be worth investigating EV tariffs once energy prices fall (whenever that may be). But experts generally don’t advise switching to an EV tariff at the moment.

If you are struggling with rising prices and can't pay your energy bills (opens in new tab), you're not alone and assistance is available. 

We know this is a difficult time for many people as household budgets come under pressure. If you need to talk to someone, there is free support from the Samaritans (opens in new tab). You can call for free on 116 123.