How Do Time-of-Use Tariffs Work With a Home Battery?
Last updated October 2026
A time-of-use tariff charges different prices for electricity at different times of day. Paired with a battery, it lets you buy electricity when it is cheaper and use it when it would otherwise cost more. This guide explains the main tariff types, how a battery follows them and what to check before you switch.
What is a time-of-use electricity tariff?
A time-of-use tariff sets different unit prices for different times of day instead of one flat rate. Usually there is a cheaper off-peak window, often overnight, and a more expensive peak period, typically late afternoon into early evening. Some tariffs change prices every half hour based on wholesale costs.
- Fixed off-peak window: a set cheaper period each night
- Peak and off-peak with export: different prices for buying and selling at different times
- Dynamic tariffs: prices change every half hour and are published in advance
- Electric vehicle tariffs: cheaper overnight rates that a battery can also use
How does a battery use a time-of-use tariff?
The battery charges during the cheap window and discharges during peak hours, so your home draws less from the grid when prices are highest. Most batteries can follow a schedule, and many can link to supported tariffs automatically, adjusting charging each day without you needing to change settings.
If you also have solar panels, the battery can store daytime surplus too. In a Scottish winter, solar output is low, so off-peak grid charging often does more of the work; in summer, solar can cover far more of your use.
Which tariff is best with a battery in Scotland?
There is no single best tariff. The right one depends on how much electricity you use, when you use it, whether you have solar or an electric vehicle, and how comfortable you are with changing prices. Compare the off-peak rate, peak rate, standing charge and any export rate together.
Electricity prices and standing charges vary between regions, including the two Scottish regions, so always compare prices for your own postcode. Tariffs change often, so it is worth reviewing yours once a year.
Do I need a smart meter for a time-of-use tariff?
Yes. Time-of-use tariffs rely on a smart meter that records your usage in half-hour periods, so your supplier can bill each period at the right price. If you do not have one, ask your energy supplier to fit one before or alongside your battery installation.
Once your smart meter is working, your supplier’s app or online account will usually show half-hourly data. That data is also the best way to size a battery correctly.
Can I sell stored electricity back to the grid?
Some tariffs pay for electricity exported from your home, and a few pay more at peak times. If you have solar, you can usually register for export payments under the Smart Export Guarantee. Whether exporting from a battery makes sense depends entirely on your tariff’s terms and rates.
Exporting requires your installer to notify your network operator and set the system up correctly. Check your supplier’s eligibility rules, as some export tariffs require solar panels or specific equipment.
Frequently asked questions
Will a battery charge automatically at the cheap rate?
Yes, once it is set up. You or your installer set a charging schedule, or link the battery to a supported tariff so it adjusts itself. You can usually change the settings in an app.
What happens if I use more than the battery holds?
Your home simply draws the rest from the grid at whatever rate applies at that time. Nothing switches off; you just pay the normal price for the extra electricity.
Are dynamic tariffs risky?
Prices on dynamic tariffs can rise sharply at times. A battery helps by avoiding the most expensive periods, but you should be comfortable with changing prices and check whether the tariff includes a price cap.
Can I switch tariff after my battery is installed?
Yes. The battery is not tied to a supplier. You may need to update its schedule or app settings so it follows the new tariff’s off-peak times.
Does a battery help with Economy 7?
It can. A battery charged during the Economy 7 off-peak period can cover some daytime and evening use. A newer smart time-of-use tariff may offer more flexibility, so compare both.