A time-of-use tariff charges different prices at different times of day, and it suits a home with solar panels and a battery. You charge the battery when power is cheap and use it when power is dear. Your panels fill it for free on sunny days.

The best tariff depends on your set-up. Energy Saving Trust says that with solar alone, the best Smart Export Guarantee rate is usually the better choice. With a battery, a time-of-use tariff starts to earn its keep.

How a time-of-use tariff works

Most standard tariffs charge one price per unit all day. A time-of-use tariff, however, sets two or more prices. Cheap periods often fall overnight, and dear periods fall in the early evening.

Your smart meter records when you use power, in half-hour blocks. The supplier then bills each block at its own price, because the meter data shows when you used it. That is why you typically need a smart meter, as Energy Saving Trust notes in its smart charging advice.

Ofgem says its price cap for default tariffs averages 26.32p per kWh from 1 October 2026, excluding VAT. A time-of-use tariff may beat that in its cheap hours, but it may cost more in its peak hours. So the tariff only helps if you shift enough use, since you pay more in the dear hours.

The main tariff types

Energy Saving Trust describes several kinds in its tariff guide, updated in August 2026. Each suits a different set-up.

  • Economy 7 has one cheaper period at night and dearer power by day. It is available to anyone.
  • Dynamic tariffs change price every half-hour, based on what power costs to produce at that time.
  • Solar and battery tariffs give different rates for importing and exporting power. You need solar panels and a battery to get one.
  • EV tariffs give one very cheap period in the early hours for charging a car.
  • Smart Export Guarantee tariffs pay a fixed rate for every unit you export. They are not time-of-use tariffs, because the rate stays the same all day. However, you can use one alongside a time-of-use tariff.

Our guide to the Smart Export Guarantee covers export rates. The hub on batteries and export gives the full picture.

Ofgem adds that some suppliers offer half-price or lower-cost electricity at weekends, and most people with a smart meter can use these offers. Ofgem reviews the price cap every three months, so default prices also move. As a result, a tariff that looks cheap today may look different in the new year.

Which tariff suits solar and a battery

Energy Saving Trust looked at over a million tariff and technology combinations. For solar panels with a battery, it says you can choose one of two routes.

The first is a dedicated solar and battery tariff, built for this pairing. The second is a good export rate matched with a dynamic or Economy 7 import tariff, although you must watch the terms. Energy Saving Trust found there does not seem to be much difference between the two.

For solar panels only, the advice is different. Look for the best export rate. Energy Saving Trust says that to get the best rate you need to switch to the same company for import and export. So check the import rate as well, because it probably will not be a time-of-use tariff.

For a battery without solar, Energy Saving Trust says a dynamic tariff or Economy 7 is best. It adds that few people do this, because the savings are unlikely to pay off the cost of the battery. Our guide to solar battery cost and sizing helps you judge that cost.

A real example: Octopus Flux

One named example helps to show how these work. Octopus Energy sells Flux for homes with solar panels. It says the super-cheap period runs from 2am to 5am and the peak runs from 4pm to 7pm, all year round. Flux has three price periods, and it covers both import and export.

You need solar panels and an export meter point number to join, while the smart meter must be a type Octopus can read. You also need to be on an import and export tariff with Octopus. The rates are flexible, so they can change with wholesale prices. There are no exit fees, Octopus says.

Octopus Energy’s Intelligent Octopus Go suits homes with an electric car. It offers 7.6p per kWh for smart charging, with a cheap window from 11:30pm to 5:30am. Octopus says it currently offers only fixed rates on this tariff, with a £50 early exit fee. Octopus last checked these figures in October 2026.

These are examples, not recommendations. Rates and terms change often, so always check the supplier’s page before you switch. Energy Saving Trust cannot recommend specific tariffs either, and nor can we.

How to get the most from your tariff

A tariff only saves money when your habits match its prices. Start by writing down the cheap and dear periods. Then check what your battery, hot water and car do in each one.

Once you pick a tariff, set up your equipment to match. Energy Saving Trust gives three simple steps, since each device can shift its use.

If you have a battery, set it to charge when power is cheap and discharge when power is dear. If you have electric water heating, heat the cylinder in cheap periods. If you have an electric car, set the charger or the car to charge in the cheap window.

Your system may already have settings for common tariff types. If you are unsure, therefore, ask your installer. Our post on charging an electric car from solar panels shows how this works in a home with both.

You can also use cheap periods for hot water. A solar diverter for hot water sends spare solar power to your cylinder first. Meanwhile, solar panels and heat pumps can pair well with a heat pump tariff.

Winter, monitoring and common mistakes

Output falls in winter, so your panels fill the battery less often. In that season, however, a cheap overnight rate can top up the battery instead. Our guide to solar panels in winter explains the drop in output.

Watch your app to see whether your plan works, because the graphs show when you buy and when you export. Our guide to reading your solar monitoring app shows what the graphs mean. Then look for ways to use more of your own solar power.

One mistake to avoid is chasing a cheap rate while ignoring the dear one. A tariff with a very cheap night rate may have a steep evening peak. Your home uses power in the peak too, so check your own pattern first.

Finally, remember that these tariffs apply to everything in your home, not only your battery, so check the peak hours carefully. For the big picture on value, see whether solar panels are worth it. Our hubs on solar panel costs and savings, how solar panels work and solar panel maintenance and lifespan add more detail.

Sources

Common questions

What is a time-of-use tariff?

It charges a different price for electricity at different times of day. Energy Saving Trust calls these smart time-of-use tariffs. They reward you for using power when it is cheap and avoiding it when it is dear.

Do I need a battery to benefit?

No. Energy Saving Trust says that with solar panels alone you are probably best off finding the best Smart Export Guarantee rate. A battery lets you shift power between cheap and expensive periods, which is where these tariffs help most.

Do I need a smart meter?

Yes, in practice. Energy Saving Trust says you typically need a smart meter to get these tariffs, because the supplier must record when you use power. Octopus Energy says its tariffs need a SMETS2 meter or a SMETS1 meter made by Secure.

Are time-of-use tariffs fixed?

Not always. Octopus Energy says Flux is flexible, so its rates can rise and fall with wholesale prices. Other tariffs are fixed for a set term, sometimes with an exit fee. Read the terms before you switch.

Will a time-of-use tariff raise my bill?

It can, if you use lots of power in the dear periods. The tariff applies to all the electricity in your home. Check your own usage pattern against the peak times before you switch.