Energy tariffs with free electricity hours: UK comparison guide
Some UK tariffs offer discounted or “free” electricity in certain hours (often overnight or weekends). This guide explains how they work, who they suit, and how to compare them safely.
- Understand “free hours” vs higher peak rates (and when it costs more)
- Check eligibility: smart meter, region, payment method and exit fees
- See two realistic household examples with estimated numbers and assumptions
Estimates only. Tariff availability and terms vary by supplier, region, meter type and payment method.
Fast answer: are “free electricity hours” tariffs worth it?
They can be worth considering if you can shift a meaningful chunk of your electricity use into the free/cheap window (for example, EV charging, tumble dryer, dishwasher, washing machine, immersion heater or storage heating). If you can’t, the higher peak unit rate many of these tariffs use may cancel out the benefit.
Usually suits
- EV owners charging mostly at home
- Homes with a smart meter and flexible routines
- Households that can run appliances overnight/weekend
Often not ideal for
- High daytime electricity users (WFH + electric cooking)
- Those who can’t shift usage (young children, care needs)
- Prepayment customers (availability can be limited)
Quick checks before you switch
- Is a smart meter required?
- What are the peak unit rate and standing charge?
- Any exit fees or time-limited promo terms?
Important: “Free hours” usually means the electricity unit rate is 0p/kWh for set hours. You may still pay a daily standing charge, and electricity used outside the free window can be priced higher than a standard single-rate tariff.
How free-electricity-hours tariffs work (UK)
In the UK, these tariffs are a type of time-of-use pricing. Instead of one unit rate all day, you get different prices by time band. Some suppliers market one band as “free” for a fixed number of hours.
Common UK formats you’ll see
- Free hours (e.g. 3–6 hours)
- Unit rate is 0p/kWh during set times. Outside that, rates can be higher than standard.
- Cheap off-peak (EV-style)
- Very low overnight rate (not necessarily free). Often paired with a higher daytime rate.
- Multi-rate (legacy Economy 7 / Economy 10)
- Two (or more) rates based on your meter setup. Not “free hours”, but similar comparison logic applies.
Eligibility factors that matter in the UK
- Meter type: many require a communicating smart meter to record half-hourly usage.
- Region: unit rates and standing charges vary by distribution area (e.g. Northern Scotland vs London).
- Payment method: Direct Debit can have different pricing vs pay-on-receipt; prepayment availability can be limited.
- Fuel: many free-hours deals are electricity-only benefits; gas is usually a separate rate.
- Contract terms: fixed vs variable, exit fees, and whether the free-hours feature can change with notice.
Safety note: If you plan to run appliances overnight, follow manufacturer guidance and don’t take risks (for example, avoid using damaged chargers, keep airflow clear, and consider using timers/built-in scheduling features where appropriate).
Compare tariffs (whole of market) — get a quote
Tell us a few details and we’ll show available tariffs for your home, including time-of-use and any tariffs with free/discounted hours where offered. This is a quote request, not a commitment.
What to gather before comparing (2 minutes)
1) Your meter set-up
Smart / standard / Economy 7. If you have an In-Home Display, it often shows “SMETS”.
2) Your rough usage
From a bill (kWh) or estimate: low/medium/high electricity use.
3) When you use power
Do you have flexible loads you can move into the free hours?
4) Contract details
Any exit fees, end date, or bundled offers that could affect switching.
Compare free-hours tariffs vs standard tariffs (what to look at)
A proper comparison uses your expected split of usage across peak and free/cheap hours. Below is a practical checklist and a simple table of what to check before deciding.
| What you’re comparing | Free-hours / time-of-use tariff | Standard single-rate tariff | Why it matters |
|---|---|---|---|
| Peak unit rate (p/kWh) | Often higher to offset free/cheap window | Same rate all day | If most of your use is daytime, this can dominate your bill. |
| Free/cheap hours window | Fixed times (e.g. overnight/weekend) and can differ by tariff | Not applicable | You only benefit if you can reliably shift usage into these times. |
| Standing charge (p/day) | Can be similar or higher | Varies by supplier/region | You pay it regardless of usage; affects low-usage homes most. |
| Smart meter requirement | Common (half-hourly settlement/reads) | Not always required | Without it, you may not be eligible or you may be moved to a different product. |
| Exit fees / contract | Some fixed deals have fees | Varies | If the tariff doesn’t suit after a few months, fees can matter. |
Decision checklist (quick)
- Can you move 25%+ of electricity into the free/cheap window? (EV charging often makes this easy.)
- Are the free hours at times you’ll actually use (or schedule) energy?
- Is the peak rate still competitive for your region?
- Is the standing charge reasonable for your usage level?
- Do you need (or already have) a smart meter, and is it communicating?
- Any exit fees, and are the free-hours terms fixed or changeable?
Two realistic scenarios (estimated numbers)
These examples show how the maths works. They are illustrative only (rates vary by supplier, region and time).
Scenario A: EV household that can shift usage
- Electricity use: 3,600 kWh/year
- Shiftable into free hours: 1,200 kWh/year (EV charging scheduled)
- Example rates: free hours 0p/kWh; peak 30p/kWh; standard tariff 25p/kWh
Estimated annual unit-cost comparison (excluding standing charge):
Free-hours tariff: (2,400 kWh × 30p) + (1,200 kWh × 0p) = £720
Standard tariff: 3,600 kWh × 25p = £900
Estimated difference: £180 (before standing charges and any gas costs).
Scenario B: Daytime-heavy household that can’t shift much
- Electricity use: 2,900 kWh/year
- Shiftable into free hours: 300 kWh/year
- Example rates: free hours 0p/kWh; peak 33p/kWh; standard tariff 26p/kWh
Estimated annual unit-cost comparison (excluding standing charge):
Free-hours tariff: (2,600 kWh × 33p) + (300 kWh × 0p) = £858
Standard tariff: 2,900 kWh × 26p = £754
Estimated difference: standard tariff is £104 cheaper (before standing charges).
Assumptions used: electricity-only unit costs shown; standing charges excluded because they vary by region and tariff; “shiftable kWh” is estimated and depends on behaviour and device scheduling.
Costs, exclusions and common pitfalls (UK)
“Free hours” tariffs can be great for the right home, but they’re easy to misjudge. Here are the most common gotchas we see when people compare.
1) Peak rate wipes out the benefit
If most usage stays in peak hours (often daytime/evening), a higher unit rate can cost more overall—even with some free electricity.
2) Standing charge still applies
A 0p/kWh window doesn’t remove the daily standing charge. Low-usage homes should compare standing charges carefully.
3) Smart meter & readings
Many time-of-use tariffs require half-hourly reads. If your smart meter isn’t communicating, you may not get the intended rates.
4) Window timing may not match your life
“Free” might be overnight, weekends, or a fixed block. If you can’t schedule devices then it’s less useful.
5) Export/solar and EV specifics
If you have solar, battery storage or an EV, check how import/export rates interact. Some tariffs are designed around EV charging patterns.
6) Exit fees and changing terms
Fixed deals can have exit fees. Variable tariffs can change rates with notice—always read the tariff information label/terms.
Practical tip: If you have a smart meter, check your supplier app or in-home display and estimate what share of your electricity you can move to the free/cheap window. Even a rough split (e.g. 10%, 25%, 40%) helps avoid the most common mistake: focusing on “free” without checking the peak rate.
FAQs: free electricity hours tariffs in the UK
Are free electricity hours really free?
During the stated hours, the unit rate may be 0p/kWh, but you’ll usually still pay a standing charge. And the unit rate outside the free window can be higher than a standard tariff, so total cost depends on when you use electricity.
Do I need a smart meter for free-hours tariffs?
Often, yes. Many time-of-use tariffs rely on half-hourly readings to bill different rates at different times. If you don’t have a smart meter, you may be limited to standard tariffs or legacy multi-rate options (like Economy 7) depending on your set-up.
How do I compare a free-hours tariff with my current tariff?
You need three ingredients: (1) your annual kWh usage, (2) an estimate of what % you can shift into the free/cheap hours, and (3) the unit rates + standing charges for both tariffs. If you can’t estimate the split, use a conservative assumption (e.g. 10–20%) and see whether it still stacks up.
Will I pay more for electricity in the daytime?
Possibly. Many free-hours tariffs have a higher peak unit rate than a standard tariff. That’s why they tend to suit people who can move a large, predictable load (like EV charging) into the free window.
Are these tariffs available everywhere in the UK?
Availability and pricing can vary by region (your electricity distribution area), meter type and payment method. Some tariffs may be restricted to customers with smart meters, EVs, or specific account set-ups. Enter your postcode to see what’s available where you live.
Can tenants switch to a free-hours tariff?
In many cases, yes—if you pay the energy bills and have permission under your tenancy agreement to change supplier. If you’re in a fixed-term contract, check exit fees. If the property has a prepayment meter or complex metering (e.g. communal heating), options may be more limited.
What about Economy 7—does it count as free hours?
Economy 7 usually offers a cheaper night rate (not free) and a more expensive day rate. The comparison logic is similar: it can work well if you use a lot of electricity overnight (storage heaters, immersion heater, EV charging) and less well if your usage is mostly daytime.
Can I switch back if it doesn’t work out?
Usually yes, but check whether your tariff is fixed and has exit fees. Also consider whether switching affects your meter configuration (for example, moving between multi-rate and single-rate products). If you’re unsure, choose quotes that clearly show contract length and fees.
Trust, methodology and sources
Page info
- Written by: EnergyPlus Editorial Team
- Reviewed by: Energy Specialist
- Last updated: March 2026
How we assess “free hours” tariffs (transparent methodology)
Our goal is to help you compare tariffs in a way that reflects real UK billing: unit rates by time band plus standing charges, with eligibility constraints clearly flagged.
- We compare total estimated cost using your expected kWh usage and an estimated split between peak and free/cheap hours.
- We treat “free” as 0p/kWh only within the published window and only where the supplier terms state this; standing charges still apply.
- We check constraints that commonly affect availability: postcode region, payment method, meter type (smart vs standard vs multi-rate), and contract terms/exit fees.
- We avoid assumptions about savings: results depend heavily on behaviour (when you actually use electricity) and device scheduling.
Limitations: Rates and tariff structures change. Some time-of-use products can update prices or time bands with notice. Always confirm the tariff details and the tariff information label before switching.
Helpful UK sources
- Ofgem (UK energy regulator) — guidance on switching, prices and consumer protections.
- Citizens Advice: energy — independent advice on bills, meters and supplier issues.
- GOV.UK: smart meters — what smart meters are and how they work.
Ready to check free-hours tariffs for your postcode?
Compare whole-of-market home energy tariffs, including time-of-use options where available. We’ll show estimates clearly so you can judge whether free hours actually suit your usage.
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