Energy tariffs with free electricity hours: are they worth it in the UK?
Free-hours electricity deals can be great if you can shift a chunk of usage into the free window — but many UK households pay a higher unit rate the rest of the time. Use this guide to work out whether you’re likely to be better off, with UK-specific examples and a simple checklist.
- Best suited to homes that can reliably move 20–40% of electricity use into the free hours (e.g., EV charging, heat pump scheduling, hot water).
- Not automatically cheaper: higher daytime unit rates (and sometimes higher standing charges) can cancel out the “free”.
- Meter & set-up matters: smart meter compatibility, storage heaters, and whether you can automate appliances safely.
Estimates only. Availability, prices and free-hour rules vary by supplier, region and meter type.
Fast answer: yes — but only if you can use the free hours properly
In the UK, tariffs with free electricity hours can be worth it when you can consistently shift a meaningful share of your electricity into the free window (often overnight or set daytime blocks). If you can’t, you may pay more overall because the supplier often recovers the “free” cost through higher paid unit rates (and sometimes a higher standing charge).
Usually worth considering if…
- You have an EV and can charge mainly in the free hours.
- You can time heavy loads (dishwasher, washing machine, tumble dryer) safely.
- You have a heat pump or immersion/hot water cylinder you can schedule.
- You have a smart meter and your supplier supports half-hourly billing.
Often not worth it if…
- Your home is occupied all day and you can’t shift usage.
- You already have a cheap fixed deal you can keep for months without exit fees.
- You’re on prepayment and the tariff isn’t available to you.
- You have storage heaters and your current Economy 7 set-up already fits your pattern.
Quick rule of thumb
Ask: “What % of my electricity can I move into the free window every week?”
- Under ~15%
- Free-hours tariffs often struggle to beat competitive standard/fixed deals.
- ~20–40%
- Usually the sweet spot, especially with EVs and automation.
- Over ~40%
- Can be very strong — but double-check any higher paid rates and standing charges.
Important: “Free” usually means the unit rate is £0/kWh for certain hours. It does not normally remove the standing charge, and gas (if included) is typically charged as normal.
Check free-hours tariffs available to you
We’ll compare whole-of-market style options (where available) and show you whether a free-hours deal could suit your meter type and usage pattern. No pressure — the form helps us return accurate options for your area.
What you’ll need
- UK postcode
- Whether you have a smart meter (if you know)
- Rough monthly usage or last bill (optional)
What we’ll highlight
- Free-hour windows and any caps
- Paid unit rates & standing charge
- Exit fees and fixed-term length
- Eligibility (payment method, meter)
Tip: If you have an EV, include that in any follow-up notes — it’s often the deciding factor for free-hours value.
Get your tailored comparison
How “free electricity hours” tariffs work (UK)
These tariffs set your electricity unit rate to £0/kWh for specific hours. Outside those hours, you pay a (often higher) unit rate, plus a daily standing charge.
- Free window: e.g., a nightly block, or a few hours on certain days.
- Paid window: all other times, sometimes with a premium rate.
- Eligibility: commonly requires a smart meter and half-hourly reads.
- Rules vary: some deals have caps, exclusions, or require you to be on direct debit.
The key question to ask suppliers
- Exactly which hours are free (and are they fixed year-round)?
- Is there a usage cap during free hours?
- What are the paid unit rates (day/evening) and standing charge?
- Any exit fees or minimum term?
- Is it available for prepayment, Economy 7, or specific smart meters?
Safety note: Only run appliances unattended if the manufacturer permits it and you’ve checked basic safety (e.g., dryer lint filters, correct ventilation). Timers and smart plugs can help, but don’t override safety guidance.
Free-hours vs Economy 7 vs a typical single-rate tariff
The best tariff type depends on when you use electricity, not just how much. This table shows what to compare (terms and rates vary by supplier and region).
| Tariff type | Best for | Main advantage | Watch-outs |
|---|---|---|---|
| Free electricity hours | EV owners, heat pumps, households with timers/automation | £0/kWh during set hours can cut costs if you shift usage | Higher paid rates; free window may not match your routine; eligibility rules |
| Economy 7 / multi-rate | Storage heaters, overnight-heavy use (legacy set-ups) | Cheaper night rate for a long window (often ~7 hours) | Day rate can be much higher; timing varies by region/meter |
| Single-rate (standard/fixed) | Most households with mixed day/evening use | Simple; no need to track time windows | No special cheap/free periods for heavy loads |
Decision checklist (print this mentally)
- Do the free hours match my life? (work patterns, school runs, bedtime routine)
- Can I automate safely? (EV schedule, immersion timer, smart plugs)
- What’s my current deal? (exit fees, end date, fixed vs variable)
- What’s the paid unit rate? Compare like-for-like including standing charge.
- Any caps or exclusions? (free kWh limit, weekend-only, device restrictions)
- Meter & payment eligibility? (smart meter, direct debit, prepay availability)
A simple break-even way to think about it
A free-hours tariff tends to work when:
(Your free-hours kWh × your current unit rate) is greater than (your paid-hours kWh × any extra premium you pay on the free-hours tariff) plus any difference in standing charge.
You don’t need perfect maths — the scenarios below show how this plays out with realistic numbers.
Two realistic UK scenarios (with numbers)
These are illustrative estimates to show the mechanics. Actual results depend on your tariff rates, standing charges, and how reliably you can shift load into free hours.
Scenario A: EV owner who can shift a lot (often works well)
Household: 3-bed, one EV, can schedule charging overnight. No gas changes considered.
- Assumptions
- Monthly electricity: 450 kWh. Free-hour share: 180 kWh (40%) (mostly EV). Paid-hour share: 270 kWh.
- Single-rate baseline: 26p/kWh, standing charge ignored for simplicity (assume similar).
- Free-hours tariff: free hours 0p/kWh; paid hours 34p/kWh.
- Estimated monthly cost
- Baseline: 450 × £0.26 = £117.00
- Free-hours tariff: 180 × £0.00 + 270 × £0.34 = £91.80
- Estimated difference
- About £25/month less (before any standing charge differences).
What could change this: if the paid-hours rate is much higher (or you don’t actually hit 40% in free hours), the advantage shrinks fast.
Scenario B: No EV, limited shifting (often not worth it)
Household: 2 adults at home evenings/weekends, no EV, can run washer/dishwasher overnight occasionally.
- Assumptions
- Monthly electricity: 250 kWh. Free-hour share: 35 kWh (14%). Paid-hour share: 215 kWh.
- Single-rate baseline: 26p/kWh.
- Free-hours tariff: free hours 0p/kWh; paid hours 34p/kWh.
- Estimated monthly cost
- Baseline: 250 × £0.26 = £65.00
- Free-hours tariff: 35 × £0.00 + 215 × £0.34 = £73.10
- Estimated difference
- About £8/month more (before any standing charge differences).
What would make it work: a bigger free window you can actually use, a smaller premium on paid hours, or a major shiftable load (EV/heat pump/hot water).
Note: We excluded standing charges to keep the examples readable. When comparing real tariffs, include standing charge differences and any exit fees.
Costs, exclusions and common pitfalls (UK)
Free-hours tariffs aren’t “bad” — they’re just easy to misunderstand. These are the most common reasons people end up paying more than expected.
1) Higher paid unit rate
Many deals offset free hours by charging more per kWh outside the window. If most of your cooking/heating/entertainment is in the evening, that premium can dominate.
2) Standing charge differences
Standing charges can vary by supplier and region. A small daily difference can outweigh “free” savings if your electricity use is low.
3) Free hours you can’t use
If the free window is overnight but you don’t have an EV, heat pump, or hot water tank to schedule, you may struggle to move enough kWh.
4) Eligibility constraints
Some tariffs are restricted to smart meters, direct debit, or certain meter configurations. Prepayment and multi-rate set-ups may have fewer options.
5) Exit fees & fixed terms
If you’re on a fixed tariff, leaving early can involve exit fees. Always check your current contract end date before switching.
6) Load shifting pitfalls
Running appliances at night isn’t for everyone. Consider noise, safety guidance, and whether you’ll actually keep the routine long-term.
FAQs
Do free electricity hours tariffs exist for gas too?
Typically, free-hours promotions apply to electricity only. If the tariff is dual fuel, your gas unit rate and standing charge are usually charged as normal.
Do I need a smart meter for free-hours tariffs?
Often, yes. Many suppliers need a smart meter so they can measure usage by time (half-hourly). Some deals may work with certain multi-rate meters, but availability varies.
Can tenants use these tariffs?
In most cases, yes — if you pay the energy bills and you’re allowed to switch supplier. If you have a prepayment meter or landlord-managed bills, your options may be limited.
Are free-hours tariffs the same as Economy 7?
No. Economy 7 usually gives a cheaper night rate (not free) for a set number of hours. Free-hours tariffs give a 0p/kWh window but may charge a higher rate at other times.
Will I definitely save money if I have an EV?
Not definitely. EVs often make free-hours tariffs more attractive, but it depends on the paid unit rate, how much you charge at home, and whether the free window aligns with your charging schedule.
Can suppliers change the free hours?
Tariff terms vary. Some deals have fixed hours, while others may allow changes with notice under their terms. Always check the tariff information and any notifications policy before switching.
Is there a cap on how much “free” electricity I can use?
Some tariffs may have caps, fair usage policies, or specific rules for how the offer applies. If a cap exists, compare it against your EV/heat pump needs so you’re not paying the higher rate unexpectedly.
Could switching affect my Warm Home Discount or other support?
Warm Home Discount eligibility is scheme-based and supplier participation can vary by year. If you receive support, check the supplier’s current policy and your eligibility before switching.
Trust, methodology and sources
Page accountability
- Written by
- EnergyPlus Editorial Team
- Reviewed by
- Energy Specialist
- Last updated
- March 2026
How we assess whether a free-hours tariff is “worth it”
- We compare the whole bill shape: paid unit rates, standing charges, and the free window rules — not just the headline “free”.
- We focus on shiftable kWh: we estimate how much electricity a typical household can realistically move (EV charging, hot water, heat pump pre-heat, laundry).
- We use transparent scenarios: the examples on this page show the same usage under different rates to illustrate break-even behaviour.
- We flag UK constraints: regional pricing differences, payment method eligibility (e.g., direct debit vs prepay), and meter compatibility.
Limitations: We can’t guarantee availability or pricing because suppliers can change tariffs, restrict sign-ups, or vary rates by region. Always check the supplier’s tariff information before you agree.
Useful UK sources
- Ofgem (UK energy regulator) — guidance on switching, consumer protections and market rules.
- Citizens Advice: Energy — practical help with bills, meters and switching.
- GOV.UK: Energy — official information on support schemes and household energy topics.
Want to know if a free-hours tariff will actually cut your bill?
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