Thinking about switching your electricity tariff? You might have heard about time-of-use (ToU) tariffs—plans where the price you pay depends on when you use electricity. For homeowners with solar panels, a heat pump, EV, or a home battery, this could be a game-changer.
Here’s what you need to know—and how you can make the most of it.
Most UK homes (around 91%) are still on flat-rate tariffs, paying the same per unit no matter the time of day. But electricity isn’t equally expensive all day. By moving your usage to off-peak periods or storing your solar energy for the right time, you can pay less without using less energy.
Not every home benefits equally. Nesta’s research highlights three types of “tech-savvy” households that get the most out of ToU tariffs:
1. Electric-Heating Homes
Homes where heating is primarily electric, including heat pumps.
Why it matters: Heating is one of the biggest electricity uses in a home. These homes can save money by running heating or hot water at cheaper off-peak times, like overnight.
2. EV-Heavy Homes
Homes with one or more electric vehicles.
Why it matters: EV charging is flexible—you can easily schedule charging for overnight or other off-peak periods, avoiding expensive evening peaks.
3. Super-Tech Homes
Homes that combine electric heating and EVs, often with smart devices or automation.
Why it matters: With multiple large, flexible electricity loads, these households can shift a lot of their electricity use into off-peak hours, unlocking the biggest savings.
Even if your home isn’t exactly one of these types, you can still capture benefits by identifying flexible electricity use—like heating, EV charging, or appliance timing—and aligning it with cheaper periods.
Most ToU tariffs split the day into bands: off-peak, peak, and sometimes shoulder periods. Smart meters record your energy use every half hour, allowing suppliers to vary electricity prices depending on when you use it—so your bill reflects your actual usage times.
In simple terms:
If you can shift even part of your daily consumption to off-peak hours, the savings add up. And if you have a home battery, you could charge it when electricity is cheap or from your solar panels during the day, then use that stored energy in the evening peak.
From a homeowner’s perspective, the benefits look like this:
If you can move enough electricity use into cheaper windows — washing, dishwashing, hot-water heating, EV charging, sometimes even cooking — the savings can be meaningful.
Nesta’s modelling assumes off-peak electricity can be around 40% cheaper, with peak periods around 60% more expensive. For homes with flexible loads (especially heat pumps and EVs), that difference adds up fast.
The more households shift demand away from peak periods, the less strain there is on the grid. That means fewer expensive new power stations and network upgrades.
Regulators and the government estimate that this flexibility could reduce overall system costs — helping to cut bills for all consumers over time, even those who never switch to a ToU tariff.
You’re not locked into a fixed daily pattern. You decide when to run appliances, charge your EV, or heat water.
With timers and smart controls, much of this can happen automatically — giving you more influence over your energy costs without constant effort.
Here’s why this combination works so well:
Nesta’s analysis shows homes with all three technologies on a ToU tariff have lower bills than homes with a gas boiler on a standard flat tariff.
Good to know: For homes with heat pumps, using a ToU tariff smartly could save up to £600 a year just by timing your electricity use to the cheapest periods.
You’re most likely to benefit if you:
Even if you’re not in the “tech-affluent” profiles Nesta studied, following these principles lets you capture many of the same benefits.
By shifting your electricity use to cheaper periods, you’re not just saving money—you’re helping the grid run more efficiently and reducing overall emissions.