Are Time-of-Use Energy Tariffs Worth It in 2026?

What a time-of-use tariff actually is

A standard energy tariff charges a single unit rate for every kWh of electricity, whatever time of day you use it. A time-of-use (TOU) tariff charges different prices at different times. The idea is simple: electricity is cheaper to supply when demand is low (overnight, when offices are shut and most people are asleep) and more expensive at the evening peak when everyone gets home, cooks dinner and switches on the lights.

There are two broad families in 2026:

• Two-rate tariffs such as Economy 7 (and the less common Economy 10). You get a cheap rate for a fixed block of hours overnight and a higher day rate the rest of the time. The cheap window is typically around seven hours, often somewhere between 00:30 and 07:30, but the exact hours depend on your supplier and meter, so check your own.
• Half-hourly smart tariffs such as Octopus Agile and similar products from other suppliers. The price changes every 30 minutes based on wholesale costs. Some days you get extremely cheap or even negative prices when the grid has surplus wind or solar; on cold, still winter evenings the peak price can spike well above a standard tariff.

The common thread is the trade-off. Suppliers fund the cheap window with a higher peak or day rate, and sometimes a higher standing charge. There is no free lunch: a TOU tariff only saves you money if the units you shift into the cheap hours outweigh the extra you pay during the expensive ones.

How the off-peak / day-rate trade-off works

Think of any TOU tariff as having three levers:

1. Off-peak unit rate — the cheap one you are chasing.
2. Peak / day unit rate — usually higher than a comparable single-rate tariff.
3. Standing charge — a fixed daily fee, sometimes higher on TOU deals.

The decision comes down to a single question: what share of your electricity can you genuinely move into the cheap window? If you can shift 40–60% of your usage overnight, the cheap rate dominates and you win. If you can only shift 10–15% — the usual reality for a home with no EV or heat pump — the higher day rate quietly eats the saving.

A quick worked sketch. Suppose a single-rate tariff is 27p/kWh. An Economy-7-style alternative offers 7p overnight but 33p in the day. A home using 8 kWh a day:

• On single rate: 8 kWh x 27p = £2.16/day.
• On TOU with only 1.5 kWh shifted overnight: (1.5 x 7p) + (6.5 x 33p) = 10.5p + £2.15 = £2.25/day — worse off.
• On TOU with 5 kWh shifted overnight (say, charging an EV): (5 x 7p) + (3 x 33p) = 35p + 99p = £1.34/day — a big win.

(Rates above are illustrative, not quoted prices — check the live tariffs in your area.) The lesson is stark: the same tariff can be the cheapest or most expensive option on the market depending entirely on your usage shape.

Who actually saves in 2026

EV owners — the clearest winners

If you charge an electric car at home, a TOU tariff is close to a no-brainer. An EV battery is a large, flexible load — typically 40–80 kWh — that you can schedule to charge entirely in the cheap window using the car's app or charger timer. Most EVs do roughly 3–4 miles per kWh, so at an overnight rate around 7p/kWh you are paying under 2.5p per mile for fuel. Compare that with a 45 mpg petrol car at the pump and the running-cost gap is dramatic.

If you are weighing up the switch to electric, our electric car savings calculator and the broader car running cost calculator let you compare pence-per-mile against your current car at realistic 2026 charging rates.

The one caveat: the saving collapses if you cannot charge at home and rely on public rapid chargers, which can cost five to ten times the cheap overnight rate. TOU economics assume a home charger and a working smart meter.

Heat pump owners

Heat pumps are the next-best fit. A heat pump runs on electricity and uses far more of it than lighting and appliances, so being on a cheap rate matters enormously. Many heat pumps can pre-heat the home or a hot-water tank during off-peak hours — effectively storing cheap heat for later. Some suppliers offer dedicated heat-pump tariffs with an extended cheap window precisely for this reason. If you have moved off gas, staying on a flat single rate usually leaves money on the table.

Home battery owners

A home battery turns a TOU tariff into an arbitrage machine: charge the battery on cheap overnight units, then run the house off it during the expensive evening peak. Paired with solar, this can shrink peak-rate imports to almost nothing. Batteries are expensive up front, but for households already committed to one, a TOU tariff is what makes the economics work.

Households with a dishwasher, washing machine and dryer

Even with no EV or battery, you can shift a modest amount: running the dishwasher, washing machine and tumble dryer overnight or in a cheap window. Realistically that is 2–4 kWh a day. It helps at the margin, but on its own it rarely covers the higher day rate. Treat it as a tie-breaker, not a reason to switch.

Who should probably stay on a single rate

Be honest about your home. You are likely better off on a standard single-rate tariff if:

• You have no EV, no heat pump and no home battery.
• Most of your usage lands in the early-evening peak — cooking, lighting, TV, kids' bath time.
• Your daily routine is fixed and you cannot, or do not want to, run appliances overnight (noise, fire-safety concerns about unattended dryers, flat-dwelling, shift patterns).
• You would not actively manage a half-hourly tariff and would rather have a predictable bill.

For these households, the higher peak rate on a TOU deal usually outweighs whatever small slice of usage they can shift. The convenience of one flat rate also has real value.

Economy 7 vs smart half-hourly tariffs

If a TOU tariff does suit you, the next choice is between the old and new styles.

Economy 7 is simple and predictable. Two rates, fixed hours, easy to plan around. It suits people who want certainty and have a clear overnight load (storage heaters, EV, immersion heater). The downside is rigidity: you are locked to one cheap window and a single, fairly high day rate, with no upside when wholesale prices crash.

Smart half-hourly tariffs (Octopus Agile and equivalents) can be cheaper still and reward active management — moving usage to the genuinely cheapest half-hours, sometimes capturing very low or negative prices. The trade-off is volatility: on a cold, windless winter evening the peak price can spike sharply, and you need a smart meter sending half-hourly readings plus a bit of attention to capture the gains. Automation (smart EV chargers, battery controllers, app-scheduled appliances) does most of the work, but the tariff rewards engagement.

A practical middle path some suppliers offer is a fixed cheap-window smart tariff: a guaranteed low rate for a defined block (often a few hours overnight) with a normal rate the rest of the day. That gives EV and heat-pump owners the off-peak certainty of Economy 7 without committing to half-hourly price swings.

What to check before you switch

1. Confirm your smart meter works in smart mode. Half-hourly tariffs need it. After switching supplier a meter can drop into 'dumb' mode — ask for it to be re-commissioned.
2. Read the off-peak hours carefully. A cheap window that ends at 05:30 is no good if your EV finishes charging at 06:00. Match the window to your actual schedule.
3. Compare the peak rate and standing charge, not just the off-peak rate. A headline 7p overnight rate means little if the day rate and standing charge are inflated.
4. Estimate your shiftable share. Roughly what fraction of your kWh can genuinely move into the cheap window? Under ~25% and a single rate is probably safer.
5. Check exit fees. Some fixed TOU deals charge to leave early. Make sure the tariff fits before you lock in.

Putting a number on it

The honest answer to "is it worth it?" is: it depends entirely on your usage shape, and you can work it out in fifteen minutes. Pull a recent bill or your smart meter's in-home display, note your daily kWh and roughly when you use it, then test it against the off-peak and peak rates of any tariff you are considering using the simple three-lever maths above.

Because energy is just one line in the household budget, it is worth seeing the saving in context. If a TOU switch saves you, say, £150–£300 a year, slotting that into the wider picture alongside what you actually take home each month helps you decide whether it is worth the hassle. Our take-home pay calculator shows your real monthly income for 2026/27, and the savings calculator shows what redirecting an energy saving into an account could grow to over a few years.

For most UK homes in 2026 the verdict is straightforward: if you have an EV, heat pump or home battery, a time-of-use tariff is very likely worth it. If you do not, do the maths before switching — and do not be surprised if a plain single rate wins.