What are ‘free electricity hours’ tariffs in the UK?

Free electricity hours tariffs are time-of-use energy deals that offer a set window (or windows) where the unit rate for electricity is reduced to £0/kWh (or heavily discounted). Outside those hours, the unit rate is typically higher than a standard tariff. They can work well if you can reliably shift high-usage activities—like EV charging, washing/drying, dishwashers, or immersion heating—into the free period.

Are energy tariffs with free electricity hours actually worth it?

They’re worth it when the savings you make by moving enough electricity into the free window outweigh any higher prices you pay at other times (and any higher standing charge, if applicable). In practice, they suit households that can shift a meaningful share of usage—especially EV owners and people who can run appliances overnight or at set times. If you can’t change when you use electricity, a standard or simple fixed tariff can be better value.

How do I work out if I’ll save money on a free-hours tariff?

Check (1) which hours are free, (2) the unit rate during paid hours, (3) the standing charge, and (4) how much electricity you can shift into the free window each week. Estimate your kWh moved (EV charging, laundry, hot water) and compare the cost on your current tariff versus the new tariff (including standing charges). If the ‘extra’ you pay outside free hours is smaller than the value of the kWh you move into the free window, it’s likely worthwhile.

Do I need a smart meter for free electricity hours tariffs?

In most cases, yes. Suppliers generally require a smart meter (or another compatible metering setup) so they can accurately record usage by time band and apply the correct rates. If you don’t have one, you may need to get a smart meter installed before you can switch to a free-hours or time-of-use tariff.

Are free electricity hour tariffs good for EV charging?

Often, yes—EV charging is one of the easiest large loads to shift into a set time window. If your free period aligns with when your car is usually plugged in, you can reduce charging costs significantly. Just confirm any limits, fair-use policies, or requirements (such as a compatible smart meter) and compare the non-free rates against your typical daytime usage.

What are the downsides or risks of ‘free electricity’ tariffs?

Common downsides include higher electricity unit rates outside the free period, a higher standing charge, and the risk that you don’t shift enough usage to benefit. Some households may also find the timing inconvenient. Always check the exact free hours, whether weekends differ, and how prices apply at other times before switching.

Can I run appliances like washing machines and dishwashers during free hours?

Yes, if it’s safe and practical for your household. Use delay-start functions, keep appliances maintained, and follow manufacturer safety guidance—especially for running appliances overnight. Shifting these regular loads into free periods can improve the value of the tariff, particularly when combined with EV charging or hot water heating.

How can Energy Plus help me choose the best tariff?

Energy Plus can help you compare tariffs and identify whether a free-hours plan fits your usage patterns—so you can switch with confidence. Start by reviewing your current costs and when you use most electricity, then explore your options at https://www.energyplus.co.uk/ to find a tariff that suits your home and supports long-term savings.

Energy tariffs with free electricity hours: are they worth it in the UK?

Free-hours tariffs can work well if you can reliably shift a meaningful chunk of your electricity use into the free window (often overnight). This guide shows what “worth it” looks like with UK-style numbers, who they suit, and the pitfalls to check before you switch.

How free-hour tariffs typically work (and what isn’t actually “free”)
A quick decision check: EV, heat pump, battery, or flexible usage?
Two realistic scenarios with estimated costs, plus a comparison table

Check free-hours tariffs for my home How free-hours tariffs work

Estimates and availability vary by supplier, region, meter type and payment method. Always check tariff terms, standing charges and any exit fees.

Fast answer: are free electricity hours tariffs worth it?

They can be worth it in the UK if you can shift a significant share of your electricity use into the “free” window (often 3–6 hours) without increasing your overall consumption. For many homes, the main benefit comes from moving high-energy loads (EV charging, immersion heater, tumble dryer, dishwasher, washing machine) into the free hours.

Usually worth it if…

You have an EV and can charge mostly in the free window
You’ve got a home battery (or flexible appliances on timers)
You’re happy to run laundry/dishwasher overnight
Your household is already on a smart meter (often required)

Often not worth it if…

You can’t shift usage (no EV, no timers, no battery)
You’re home in the day and use most power at peak times
The tariff’s day rate/standing charge is much higher
You’re on an Economy 7/10 setup that already suits your pattern

Quick rule of thumb

If you can move 25–40% (or more) of your electricity into the free hours and the non-free unit rate isn’t significantly higher than alternatives, it’s more likely to stack up. If you’ll only shift <15%, it often won’t.

Important: “Free” typically means the unit rate for electricity is £0/kWh during the window. You’ll usually still pay a daily standing charge, and your unit rate outside the window may be higher than standard tariffs.

How free-hours energy tariffs work (UK)

Free-hours tariffs are a type of time-of-use electricity deal. The supplier sets certain hours where the electricity unit rate is £0/kWh (or heavily discounted), and a higher unit rate applies outside that window.

Typical UK features to look for

Free window: Often overnight (e.g. 3–6 hours). Some tariffs use evenings or weekends.
Smart meter requirement: Very common, because usage needs half-hourly readings.
Electricity-only vs dual fuel: Some are electricity-only. Gas usually stays on a separate unit rate and standing charge.
Regional pricing: Unit rates and standing charges vary by region and payment method.

What makes them work (or not work)

Find your “shiftable” usage: identify kWh you can move into the free hours without adding extra usage.
Compare the paid unit rate: outside the window may be notably higher than a standard tariff.
Check standing charges: a higher standing charge can erode the benefit if your usage is low.
Check practicality: timers, noise at night, and safety of unattended appliance use.

Safety note: Only run appliances unattended if the manufacturer instructions allow it and you’re comfortable with the risk. Some households prefer to shift usage to early evening/weekends (if the tariff offers that) rather than overnight.

Compare free-hours tariffs for your postcode

Tell us a few details and we’ll show available UK home tariffs (whole-of-market style comparison where possible), including time-of-use and standard options.

Tip: If you have an EV, battery, heat pump, or Economy 7/10 meter, keep a note of it. It can change which tariffs are suitable and how costs compare.

Free-hours tariffs vs other options (quick comparison)

This table is a practical way to decide what to compare next. Exact rates vary by supplier, region and payment method.

Tariff type	Best for	Watch-outs	Meter needs
Free electricity hours	EV charging, batteries, flexible households who can shift load	Higher day rate/standing charge can offset “free” window; times may not suit you	Usually smart meter (half-hourly)
Standard single-rate	Most homes; simple budgeting; low ability to shift usage	You miss out if you could shift heavy loads overnight	Any meter type
Economy 7/10 (two-rate)	Storage heaters; higher overnight use; some EV drivers	Day rate can be high; timing of off-peak matters; not ideal if you use lots of day electricity	Two-rate meter / smart meter setup
Dynamic / half-hourly pricing	Highly flexible users who can chase cheap slots (sometimes with automation)	Prices can spike at peak times; needs active management	Smart meter with half-hourly reads

Decision checklist (5-minute test)

Can you shift at least 25% of your electricity into the free window?
Do you have (or can you get) a smart meter?
Are you comfortable using timers or smart plugs (or scheduling EV charging)?
Is the free window at a time you can actually use (or charge a battery)?
Have you compared standing charge and paid unit rate against a standard tariff?

Two realistic UK scenarios (with estimated numbers)

The point of these examples is to show what has to be true for free-hours tariffs to win. Your rates will vary by supplier/region.

Scenario A: EV driver who can charge in free hours

Assumptions: 3,600 kWh/year electricity use. EV adds 2,000 kWh/year (total 5,600 kWh/year).
Standard tariff estimate: 24p/kWh, standing charge 55p/day.
Free-hours tariff estimate: 4 free hours daily; paid rate 32p/kWh outside free window; standing charge 60p/day.
Shiftable into free window: 2,200 kWh/year (mostly EV + some laundry).

Estimated annual cost (electricity only):
Standard: (5,600×£0.24) + (365×£0.55) = £1,545 (approx)
Free-hours: (3,400×£0.32) + (365×£0.60) = £1,307 (approx)
Estimated difference: about £238/year cheaper on the free-hours tariff.

Scenario B: No EV, low ability to shift usage

Assumptions: 2,900 kWh/year electricity use.
Standard tariff estimate: 24p/kWh, standing charge 55p/day.
Free-hours tariff estimate: paid rate 32p/kWh outside free window; standing charge 60p/day.
Shiftable into free window: 300 kWh/year (dishwasher/laundry occasionally).

Estimated annual cost (electricity only):
Standard: (2,900×£0.24) + (365×£0.55) = £898 (approx)
Free-hours: (2,600×£0.32) + (365×£0.60) = £1,051 (approx)
Estimated difference: about £153/year more expensive on the free-hours tariff.

These examples exclude VAT differences (typically included in advertised unit rates), do not include gas, and assume your free window is available every day. Always use your own annual kWh (from bills) when comparing.

Costs, exclusions and common pitfalls to check

Free-hour tariffs can look great in adverts. The “gotchas” are usually in the rates, meter requirements, and day-to-day practicality.

1) Higher paid unit rate

Many free-hours tariffs make up the difference with a higher rate outside the free window. If most of your usage is daytime/early evening, the maths can turn against you.

2) Standing charge

A higher standing charge hits lower-usage homes harder (many flats, single occupants, efficient homes). Compare the daily standing charge line-by-line.

3) Eligibility and meter type

You’ll usually need a smart meter set up for half-hourly readings. If you have Economy 7/10 or complex metering, confirm compatibility before switching.

4) Payment method and credit checks

Some tariffs are only available for Direct Debit, or have different rates for prepayment meters. Always check whether the offer applies to your payment method.

Other exclusions to scan in the tariff terms

Exit fees: fixed deals may charge if you leave early. Variable tariffs typically don’t, but check.
Free window changes: some suppliers can change the hours with notice. Confirm how and when.
Caps/limits: rare, but check if “free” applies to all usage or has fair-use wording.
Bundled requirements: occasionally linked to an EV tariff, app, or specific smart charging approach.
Complex households: multi-register meters, communal supplies, or landlord-controlled heating may reduce suitability.

Common mistake: “free hours” leads to more usage

The tariff only helps if you shift usage, not add new usage. If you start doing extra loads because it feels free, your bill can rise (standing charge remains, and paid-rate usage still costs more).

FAQs

Do I still pay a standing charge during the “free” hours?

Yes. The standing charge is a daily fee and applies regardless of when you use electricity. The “free” part is usually just the unit rate during a set time window.

Do I need a smart meter for free-hours tariffs?

In most cases, yes. Free-hours and other time-of-use tariffs typically need a smart meter so the supplier can apply different rates to different times using half-hourly readings.

Will a free-hours tariff work with an EV?

Often, yes—if the free window matches when you can charge and you can schedule charging reliably. Check whether the tariff has any EV-specific requirements and whether your charger/app supports scheduling.

Are free-hours tariffs the same as Economy 7?

Not exactly. Economy 7 is a two-rate setup with cheaper night electricity for a set period (often 7 hours). Free-hours tariffs are usually a newer type of time-of-use deal where some hours can be priced at £0/kWh but other hours may be priced higher.

Can the supplier change the free hours?

Some tariffs allow changes to the time bands with notice. Always read the tariff terms and the Key Information/Terms & Conditions to see how changes work and what notice you’d get.

Do free-hours tariffs help if I have solar panels?

Potentially, but it depends on when you export/import. Many solar homes use less grid electricity in daylight anyway, so the value may be lower unless you can store solar in a battery and use (or top-up) strategically. Compare using your import kWh pattern.

What about gas—does it have free hours too?

Usually no. Free-hours offers are typically focused on electricity. If you’re dual fuel, your gas will normally be charged at a standard single rate with its own standing charge.

Is it risky to leave a fixed tariff with exit fees?

It can be. If your current tariff is fixed, check for exit fees and whether you’re near the end date (fees may not apply within a set window). If you’re unsure, compare the likely annual difference against any fees before switching.

Trust, methodology and sources

Editorial trust signals

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 focus on total annual cost rather than headline offers. A free-hours tariff is more likely to be good value when the money saved during free hours outweighs (1) any increase in the paid unit rate, (2) any increase in standing charge, and (3) any behavioural changes that add extra usage.

Our scenario assumptions (so you can sanity-check them)

Rates: Example unit rates and standing charges are illustrative, and may not match current market offers in your region.
Usage: kWh figures reflect typical household ranges and EV add-on consumption, but your home may differ significantly.
Shifted usage: We assume shifted kWh truly moves into the free window (not simply added usage).
Availability: Not all tariffs are available in all regions, for all meter types, or on prepayment.

Limitations: This guide can’t account for every tariff design (multiple time bands, seasonal rates, app-based smart charging constraints). Use it to shortlist, then confirm exact terms and pricing for your home.

Sources (UK)

Ofgem (UK energy regulator) – guidance on switching, tariffs and consumer protections.
Citizens Advice: energy – practical advice on bills, meters, and dealing with suppliers.
GOV.UK: smart meters collection – smart meter programme information and consumer guidance.

Ready to see whether free hours will actually cut your bill?

Compare free-hours and standard tariffs side-by-side using your postcode and meter details. It’s the quickest way to avoid a deal that looks good on paper but doesn’t fit your usage.

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Updated on 16 Mar 2026