Energy suppliers offering free electricity days in the UK
A growing number of UK suppliers run “free electricity” sessions — led by Octopus Energy’s Free Electricity Sessions and Power-Ups — where your electricity unit rate drops to £0 for a set window. With the Ofgem price cap is £1,663/yr, pairing these sessions with a cheap underlying tariff is the smart way to cut bills. We’ll show how they work and help you compare whole-of-market home energy deals.
- Learn what “free electricity days” really mean (and what still gets charged)
- See who offers them — Octopus Free Electricity Sessions, British Gas, and more — plus the key tariff traps
- Compare whole-of-market fixes that beat the £1,663 current cap and switch with a quick form
Home energy comparison service. Availability of “free” sessions varies by supplier, region, meter type and tariff. Always check unit rates, standing charges and T&Cs.
Compare whole-of-market home energy deals (including free electricity sessions)
The cheapest 12-month fixed deals on our live panel are typically priced below the £1,663 cap, several with no exit fees — run your postcode through the comparison on this page for today's exact prices.
Fill in the form to get a personalised comparison and see whether a free-electricity tariff plus a cheap fix is genuinely cheaper for your household—or whether a standard fixed deal gives better value.
What are “free electricity days” in the UK?
In the UK, “free electricity” offers are time-based sessions tied to a specific tariff or scheme. Rather than making all your electricity free, the supplier sets your electricity unit rate to £0 during a defined window. The best-known example is Octopus Energy’s Free Electricity Sessions (and the related Power-Ups and Saving Sessions), which reward customers for using grid power when it is cheap, plentiful and greener. You may see them as:
- Free electricity sessions (a set window, announced via app/email, where the unit rate is £0)
- Free weekends (e.g., Saturday/Sunday, sometimes with hour limits)
- Free evenings or free “power hours” on selected days
- Off-peak time-of-use windows where a special low rate (not always £0) applies
These deals can be excellent for the right household—especially if you can shift usage into the free window. But the value still hinges on your underlying tariff: a session is only worthwhile if the rest of your unit rates and standing charge are competitive against the £1,663 current cap.
Which UK suppliers offer free electricity sessions — and the tariffs behind them
Sessions come and go, but a cheap underlying tariff is what protects your bill all year. Below are the kinds of supplier offers around in August 2026, alongside the cheapest fixed deals (all undercut the £1,663 current cap) and the off-peak rates EV owners can use to power free or near-free charging.
Suppliers known for free / off-peak electricity
| Supplier / scheme | What you get | Typical requirement |
|---|---|---|
| Octopus Free Electricity Sessions / Power-Ups | Unit rate dropped to £0 during announced windows when the grid is greener / oversupplied | Octopus customer with a smart meter; opt in via the app |
| Octopus Saving Sessions | Rewards for reducing usage at peak times (bill credit rather than £0 unit rate) | Smart meter with half-hourly readings; opt in each season |
| British Gas & other large suppliers | Occasional peak-saving events and off-peak EV tariffs (e.g. EV Power ~9p/kWh night rate) | Smart meter; eligible tariff; opt in where required |
Cheapest fixed tariffs in August 2026 (all beat the £1,663 current cap)
| Tariff | Typical dual-fuel cost/yr | Exit fee |
|---|---|---|
| OVO 2-year Fixed | £1,705 | Check tariff terms |
| British Gas Fixed | £1,719 | Check tariff terms |
Figures are typical dual-fuel direct-debit estimates for August 2026 and vary by region, usage and payment method. The July 2026 cap of £1,663/yr is shown for comparison.
EV & off-peak charging rates (August 2026)
| Tariff | Off-peak rate | Notes |
|---|---|---|
| Octopus Intelligent Go | 7p/kWh | Smart 6-hour window 23:30–05:30; avg saving ~£771/yr vs variable |
| E.ON Next Drive | 9p/kWh | Fixed overnight window |
| OVO Charge Anytime | ~14p/kWh | Smart-charging based |
| British Gas EV Power | ~9p/kWh | Off-peak night window |
Who benefits most from free electricity tariffs?
Households that can shift usage
If you can run appliances during a free session (laundry, dishwasher, batch cooking), your bill can drop—without changing total usage.
Smart meter customers
Free sessions and time-based tariffs work best (or only work) with smart meters, because the supplier needs accurate half-hourly readings.
EV owners & high electricity use
EV charging on a tariff like Intelligent Octopus Go (8p/kWh) plus free sessions can slash running costs against the £1,663 cap.
How free electricity sessions work (step-by-step)
- Be on an eligible tariff with a supplier that runs sessions.
Octopus Free Electricity Sessions and Power-Ups are the leading example; some larger suppliers run peak-saving events too. - Opt in and watch for the announcement.
Sessions are announced via app/email at short notice and run for a defined window. Dates vary, so set a reminder when one is announced. - Your smart meter records usage by time.
Half-hourly readings let the supplier bill the £0 unit rate correctly during the free window. - Only eligible electricity unit charges drop to £0.
The free part applies to the unit rate (kWh). Standing charge, gas, and usage outside the window are billed normally. - The cheapest 12-month fixed deals on our live panel are typically priced below the £1,663 cap, several with no exit fees — run your postcode through the comparison on this page for today's exact prices.
Typical “free electricity” components at a glance
| What you see advertised | What it usually means | What to check before switching |
|---|---|---|
| “Free electricity session” | Electricity unit rate set to £0 for an announced window when the grid is greener/oversupplied | How often sessions run, opt-in steps, your underlying unit rate & standing charge |
| “Free power hour” | A fixed hour/day where the unit rate is reduced to £0 | How often it runs, whether you can choose the hour, eligibility rules |
| “Free electricity day(s)” | Specific date(s) where the unit rate may be £0 for set hours | Which dates, whether you must opt-in, exclusions, notice period |
| “Time-of-use / EV tariff” | Different unit rates at different times; off-peak can be as low as 8p/kWh (Intelligent Octopus Go) | Peak rate, off-peak rate, charging window, smart meter requirements |
Common watch-outs (and how to avoid them)
Higher unit rates outside the free period
Standing charge still applies
Even when unit rates drop to £0, the daily standing charge remains payable (around 57.19p/day for electricity from July). Compare standing charges carefully.
Opt-in requirements and exclusions
Sessions may require you to opt in, have a compatible smart meter, or meet other criteria. Always read the eligibility details.
Not the same as Economy 7
Economy 7 offers cheaper night rates, not free electricity. A free session is separate and can have different billing rules.
Quick self-check: could a free electricity tariff work for you?
| Question | If “Yes” | If “No” |
|---|---|---|
| Do you have (or can you get) a smart meter? | More sessions and time-based tariffs become available. | You may be limited to standard single-rate deals. |
| Do you use high-load devices (EV, dryer, electric heating)? | Free windows and 7p EV rates can make a big difference. | Savings may be smaller; compare carefully. |
Eligibility and practical considerations (UK homes)
Meter type
- Smart meter: usually required for free sessions and time-based windows.
- Single-rate: may limit access to time-of-use promotions.
- Economy 7: not the same as free sessions, but can be compared alongside.
Region & network area
Availability and pricing vary by region (your local electricity distribution area). Always compare using your postcode for accurate results.
Payment method
The cheapest deals are usually monthly Direct Debit; pricing may differ versus prepayment meters. The current cap reflects direct-debit averages.
Switching timing
Switching is free, takes ~5 working days and works even without a smart meter. If you’re on a fixed deal, check exit fees and end date — Octopus charges £0, while E.ON Next and EDF charge £25/fuel.
FAQs: free electricity days & UK energy switching
Is electricity ever truly “free” in the UK?
Yes, during a free session (such as Octopus Free Electricity Sessions) the electricity unit rate (kWh) is reduced to £0 for set times. You still pay the standing charge (~57.19p/day for electricity from July), and any usage outside the window is billed at your normal rate(s).
Which UK energy suppliers offer free electricity days?
Octopus Energy is the best-known, via Free Electricity Sessions and Power-Ups, with Saving Sessions for peak reduction; some larger suppliers like British Gas run occasional peak-saving events. Offers change over time, so it’s best to compare tariffs for your postcode and check eligibility and T&Cs.
Do I need a smart meter for free sessions?
Usually yes—sessions rely on half-hourly readings to bill the £0 unit rate. You can still switch supplier without a smart meter, but most free-session and EV tariffs need one.
Will my gas be free too?
No. Sessions apply only to electricity. On a dual-fuel tariff, gas is billed under its own unit rate (around 7.33p/kWh from July) and standing charge.
How can I estimate whether I’ll save money?
Is it worth switching just for free electricity days?
Only if the underlying tariff is competitive. A few free sessions help, but the unit rate, standing charge and exit fees matter far more over a year. The cap is a unit-rate cap, not a total-bill cap, so your usage still drives the final figure.
What customers like about comparing with EnergyPlus
“I love the Octopus free sessions, but the comparison showed a lower fixed tariff cut my bills even more for my usage. Clear breakdown.”
— Homeowner, Greater Manchester
“Helpful explanation of standing charge vs unit rates with the new current cap. I switched and feel confident I understood the terms.”
— Tenant, Bristol
“The form was quick. With an EV I moved to a 7p off-peak tariff and stack free sessions on top.”
— Customer, Glasgow
Ready to see if a free electricity tariff is worth it?
Get a postcode-based, whole-of-market comparison for your home. We’ll weigh free sessions against unit rates, the £1,663 current cap, standing charges, and your usage pattern.
- Check availability in your region
- Compare estimated annual costs vs the current cap
- Switch with confidence (free, ~5 working days)
Prefer to read first? Jump to watch-outs and FAQs.
Cut your bills for good with solar
Compare free, no-obligation quotes from vetted local solar & battery installers.
Part of our tariff types hub · Ofgem price cap · compare for your postcode
Back to Energy Tariffs