Understanding time of use tariffs and energy bills.
What is a time of use tariff?
If you have an EV, a heat pump, or a solar battery, you may already be benefiting from having switched to one of our time of use tariffs. Below, we take you through how these tariffs work and what might be different about your bill if you’ve already made the switch.
If you’re new to the idea of time of use tariffs, we also dive into what’s special about these tariffs and why you should consider them.
First things first though - to understand time of use tariffs, it’s helpful to have a bit of background on where the UK’s electricity comes from.
A number of different energy sources power the UK’s electricity grid. These include renewable electricity sources like wind and solar, along with non renewable energy sources like gas and nuclear. At peak times, when lots of people are using electricity, more of it comes from gas powered sources.
With time of use tariffs, sometimes known as ‘tou tariffs’, the cost of electricity changes depending on the time of day you use it. They offer customers cheaper prices for electricity used during off-peak hours, when demand is low, and higher prices during peak hours when demand is high. Some time of use tariffs offer other periods of time with different pricing to help provide more options than peak/off-peak hours.
Let’s look at what we mean by each of these categories:
Peak hours.
Peak hours are usually in the mornings and evenings when lots of people are getting ready for work or at home, cooking dinner. Think of all those kettles boiling for cups of tea and coffee in the morning, and ovens full of delicious dinners in the evening.
Off-peak hours.
The off-peak electricity times vary depending on your meter and tariff, however they are normally a seven hour window between 11pm - 8am, for example 11pm - 6am.
How does when I use energy make a difference?
Well, if you have the flexibility to change your energy habits by shifting when you use electricity to off-peak hours, then you could save money on your electricity bills. You’d also be doing your bit to help the UK reach net zero by reducing reliance on gas powered electricity.
Is there anything else I should consider?
Yes - to qualify for a time of use tariff, you’ll need a smart meter that communicates with us. Smart meters make time of use tariffs possible by sending regular and accurate readings of your electricity use to your energy supplier.
To sign up for a time of use tariff, you need to have a smart meter that can send half hourly updates on your energy use (you’ll also need to consent to providing this data).
Smart meters are replacing Economy 7 and Economy 10 meters for time of use tariffs. These meters operate using the Radio Teleswitch Service which is being switched off in June 2025.
Do you offer time of use tariffs in the UK?
At E.ON Next, we offer a number of time of use tariffs - two variable rate tariffs - Economy 7, Economy 10, Next Drive for EV owners and Next Pumped for heat pump owners.
Economy 7.
Economy 7 offers seven hours of cheaper electricity, typically between midnight and 7am. The rest of the day, electricity is charged at a higher rate.
Economy 10.
Economy 10 offers ten hours of cheaper electricity, for example, between 1pm and 4pm, 8pm to 12am and 4am to 7am. The rest of the day, electricity is charged at a higher rate.
Next Drive.
Our time of use tariff for EV drivers offers lower-priced electricity when you charge between 12am and 7am. What’s more, it offers 100% renewable electricity at no extra cost.1
Next Pumped.
Our time of use tariff which is specially designed for customers who have a heat pump in their home. This tariff offers the option to use electricity at a lower price during off-peak hours of 4am to 7am and 1pm to 4pm, while charging a higher ‘peak’ rate during the hours of 4pm to 7pm, and a standard rate at all other hours of the day. It also offers 100% renewable electricity at no extra cost.
What are shoulder hours?
Time of use tariffs generally also offer a third category - ‘shoulder hours’ - which fall outside peak and off-peak hours. Shoulder hours have an intermediate price for the electricity you use outside peak and off-peak hours.
Why half hourly data matters for time of use tariffs and your bills.
Half hourly data is essential for time of use tariffs as it allows energy suppliers like us to charge you the right rates for your electricity. This is why having a smart meter means more accurate bills. It also means that you can see your energy consumption, and we can pay the markets accurately for the electricity you've used.
What are the benefits of half hourly data?
Half hourly data can give you detailed insights into how you’re using electricity so that you know how you can change your electricity habits. This can help you reduce your carbon footprint and save electricity and money.
In the future, we'll be able to show you your half hourly data in our app and on your bill, so you'll be able to see how much you're using in real detail. For example, your half hourly data could show you how much running your dishwasher, washing machine or tumble dryer during peak hours costs you. You could then see how much you could save by setting them to run during off-peak hours instead.
Half hourly data also helps energy suppliers like us understand customer behaviour, which can help grid operators balance electricity supply and demand more effectively and improve the overall stability of the grid.
Why do I need to provide consent for half hourly data?
You need to give consent for half hourly data because it involves sharing your personal energy consumption data with your electricity and gas supplier.
Smart meter data is classified as personal data, covered by the General Data Protection Regulation (GDPR). Energy suppliers can only use your half hourly data for specific purposes, which are defined by regulations. We’re also obligated to handle your half hourly data securely and follow relevant data protection laws.
Depending on how your energy supplier works, you’ll likely be asked for consent for half hourly data on one of a number of possible occasions - during your smart meter installation, when you sign up to a time of use tariff, through a specific consent request, or in your online account.
If you’re an E.ON Next customer you can opt in and give consent for half hourly data in your account dashboard. Go to your account settings and then click on ‘smart meter data preferences’ and click ‘Yes, change to half hourly’. If you choose not to opt in to half hourly consent and you’re on a time of use tariff, you’ll no longer be eligible for that product. This is because we need half hourly consent for those tariffs to work accurately for you.
How to access your half hourly data.
To help you monitor your energy use, you can now request your half hourly data from your smart meter. If you’re an E.ON Next customer, you can submit a subject access request (SAR) and ask us for up to 12 months reading history from your smart meter. We’ll then email this to you free of charge.
What are half hourly settlements and how do they work?
Settlement refers to the process of reconciling the difference between what energy suppliers pay for electricity with the demands of customers. While the wholesale electricity market operates on half hourly settlement periods, most residential customers used to be settled on a non half hourly basis using estimates from weeks or months. With smart meters this has changed.
With your half hourly data we can settle and you only pay for the actual amount of electricity you’ve used.
How is my energy bill calculated using half hourly data?
If you have a smart meter, half hourly settlement for your electricity consumption is now possible. Your smart meter will track your electricity consumption data every half hour and send this to us. We then use this data to work out exactly how much electricity you’ve used in each half hour period and bill you.
This is why having a smart meter means more accurate bills. Half hourly data and settlements can also help support the use of smart appliances and smart charging EVs, which rely on accurate and timely data to optimise usage.
How smart meters enable time of use tariffs.
As we’ve covered, smart meters and the half hourly data they provide, are essential for access to time of use tariffs. Beyond ensuring accurate and easier to understand bills based on actual usage, they offer ways for you to track and manage your energy consumption. They also allow you to take part in initiatives like the National Grid ESO’s Demand Flexibility Service, which can help you save energy and a bit of money too.
If you’re an E.ON Next customer and don’t have a smart meter yet, get in touch with us to arrange your smart meter installation. If you’re not with us, contact your supplier to get yours fitted.
Do I need a smart meter for a time of use tariff?
Yes - to qualify for a time of use tariff, you’ll need a smart meter that communicates with us. Smart meters make time of use tariffs possible by sending regular and accurate readings of your electricity use to your energy supplier.
To sign up for a time of use tariff, you need to have a smart meter that can send half hourly updates on your energy use (you’ll also need to consent to providing this data). Half hourly data is essential for time of use tariffs as it allows energy suppliers like us to charge you the right rates for your electricity. This is why having a smart meter means more accurate bills. It also means that you can see your energy consumption, and we can pay the markets accurately for the electricity you've used.
Smart meters are replacing Economy 7 and Economy 10 meters for time of use tariffs. These meters operate using the Radio Teleswitch Service which is being switched off in June 2025.
If you’re an E.ON Next customer and don’t have a smart meter yet, you can get in touch with us to arrange your smart meter installation. If you’re not with us, contact your supplier to get yours fitted.
How do time of use tariffs for electric vehicle (EV) charging work?
Energy suppliers also offer time of use tariffs for EV owners, allowing you to charge your EV during off-peak hours for cheaper rates. Our Next Drive tariff, for example, offers lower priced electricity when you charge between 12am and 7am.
As an extra bonus, Next Drive includes 100% renewable electricity at no extra cost, so it’s a great choice for your wallet and the planet.
What is smart charging and how will it benefit me if I have an EV?
Smart charging is a rapidly developing area of EV charging. At the most basic level it involves optimising your EV charging using your smart meter, smart EV charger and connected devices like your phone.
More advanced smart charging options include you handing over the scheduling of your EV charging to your energy supplier. They’ll create a personalised charging schedule based on your needs, taking into account the periods of time when it's cheapest to charge, and passing the benefit back to you in the form of a reward or reduced unit rate. Sounds good doesn’t it? But how about the other benefits of smart charging?
Lower EV home charging costs.
The biggest benefit of connecting our app and your charger is that it can save you money by allowing you to schedule your charges at off-peak times.
Convenience and control.
Using an app to schedule and monitor your EV charging is easy and lets you get on with your day, safe in the knowledge that your EV’s battery will be full when you need it.
Grid stability and reduced emissions.
By encouraging EV drivers to charge at off-peak times, smart charging can reduce strain on the electricity grid during peak hours. This also supports our EV transition to net zero as off-peak electricity is typically lower carbon than peak electricity.2
Maintaining your EV’s battery health.
Smart charging can help keep your EV’s battery in good health. By charging slowly overnight, you can avoid relying too much on fast chargers, which can potentially degrade battery performance over the long term. Plus, smart chargers can optimise charging and reduce stress on the battery.
How do I schedule my car to start charging at the cheapest time to use electricity?
There are a few ways you can set the charging times for your electric car. On Next Drive, the cheaper rates are the same every night, so you only have to set the charging time once. You can schedule your EV charging by:
Using the E.ON Next Home App.
With the Car Connect feature on our E.ON Next Home App you can schedule your EV charging from your smartphone, providing you have a compatible car which connects to the internet.
Using your car’s infotainment system or app.
Most electric cars allow you to set the charging times in the infotainment system. Your car may also have a separate app to schedule charging.
Bear in mind that you can still plug your EV in at off-peak times, it just won’t charge the car unless you schedule it to do so. You can always charge your car at peak times too if you need to, it'll just cost you a bit more.
Time of use tariffs are a great way to incentivise customers to use electricity when it’s cheapest and to contribute to a greener grid. By understanding peak and off-peak hours, and harnessing the power of your smart meter, you can optimise your electricity consumption and make a dent in your energy bills. EV owners in particular can make the most of time of use tariffs. If you’re starting out on your EV journey, check out our Next Drive tariff and range of smart EV chargers to benefit from cheaper overnight charging.