What Octopus actually announced
Octopus Energy confirmed in May 2026 that its Free Electricity Sessions, which pause through winter, return for the warmer months on Monday 16 June 2026. The scheme is exclusive to Octoplus members. Octoplus is the supplier's free loyalty programme and is open to any Octopus customer with a working smart meter sending half-hourly readings.
To get attention on the return, Octopus and Ford have wrapped a prize draw around the relaunch. A new Ford Puma Gen-E Premium (list price around £35,000) is the headline prize, alongside 8,000 of the supplier's pink octopus plushies. Anyone who takes part in a Free Electricity Session through the summer is entered into the draw. The prize is the marketing hook, but the actual value to a household is the free energy itself, not the chance of a car.
You will get an email the day before a session telling you the date, the start time and the duration. Sessions are usually one hour, usually in the early afternoon, usually when wind and solar output is high and wholesale prices are at or near zero. During that hour, any electricity you use above your normal baseline is free. Octopus credits it back at your unit rate within two weeks.
Free Electricity Sessions are not Saving Sessions
This trips a lot of people up, so it is worth being explicit. There are two different Octopus schemes that share the Octoplus dashboard.
| Scheme | Season | You are asked to | Reward | Underlying mechanism |
|---|---|---|---|---|
| Saving Sessions | Winter (Nov to Mar) | Use less than usual | Octopoints, redeemable against your bill | NESO Demand Flexibility Service |
| Free Electricity Sessions | Summer (Apr to Oct) | Use more than usual | Free kWh credited at your unit rate | Octopus-only, funded by negative or near-zero wholesale prices |
We covered the winter scheme in Demand Flexibility Service and home batteries. This article is about the summer scheme, which is mechanically the opposite and rewards a completely different behaviour from your battery.
Why a battery is the cleanest way to capture the value
The catch with Free Electricity Sessions is that the free energy is only useful if you actually use it. Octopus's own suggestions are practical, run the washing machine, run the dishwasher, plug in the EV, run the heat pump, do the vacuuming. The problem is that most UK households are at work between 1pm and 3pm and the appliances they want to run are in the evening. A home battery solves that mismatch by acting as a kWh buffer.
This is the same logic Habo customers already use overnight on Octopus Go, charging cheap and discharging dear. Free Electricity Sessions simply add a second, even cheaper top-up window during the day. The fact that it is the inverter doing the charging, automatically, means you are not dependent on being at home to turn on appliances.
Worked example: 11.5kWh battery, one summer of sessions
Habo Energy's standard system is an 11.5kWh battery on a sub-3.6kW inverter (we stay under 3.6kW so installation is a fast G98 notification, not a slow G99 application). In practice that gives around 3kW of usable grid-charge headroom during a session.
Assume 15 Free Electricity Sessions across the summer, roughly the 2025 cadence reported by Octopus, and a typical battery draw of 3kWh per session (one hour at 3kW). Assume your baseline household consumption in that same hour is around 0.4kWh (fridge, router, standby), so the battery is responsible for almost all of the "extra" usage above baseline.
| Item | Per session | Annual (15 sessions) |
|---|---|---|
| Free kWh into the battery | ~2.6kWh | ~39kWh |
| Value at avoided peak rate (27p) | ~70p | ~£10.50 |
| Value at avoided peak rate (30p, London/Wales) | ~78p | ~£11.70 |
| Plus laundry / EV / appliance load shifted on the same day | £1 to £2 | £15 to £30 |
The headline numbers are modest because the sessions are infrequent. The point is not that Free Electricity Sessions transform your bill, it is that they stack on top of the overnight Octopus Go arbitrage that already drives an 11.5kWh battery's roughly £900 annual saving. Free energy is free energy. The marginal cost of capturing it once your battery is installed is zero.
Why Octopus is doing this, and why it will get bigger
Free Electricity Sessions exist because the GB grid is increasingly long on renewables at midday. The National Energy System Operator (NESO) reported solar meeting roughly half of total demand on bright spring afternoons in 2026. When wind cooperates as well, wholesale electricity prices on the balancing market dip to zero or go negative. Generators get paid less than nothing to keep running, and the cheapest fix for the grid is to find someone to consume the excess. That is what these sessions buy.
This trend is structural, not seasonal. Solar deployment is still rising, offshore wind continues to come online, and Ofgem has consistently pointed at flexible demand (batteries, EVs, heat pumps) as the answer to the renewable surplus problem. The clear direction of travel is more midday cheap or free windows, not fewer.
From the supplier side, Free Electricity Sessions also lock customers into Octopus. Anyone with a battery who has set up the force-charge schedule, sized their cycles around the sessions and built up rewards in their Octoplus account has a real reason to stay. Expect competitors to follow.
How to set this up if you have a Habo battery
- In the Octopus app, opt into Octoplus and enable Free Electricity Sessions notifications. You only do this once.
- Confirm your smart meter is sending half-hourly readings. If your in-home display has been blank or your supplier still asks for manual readings, Octopus cannot calculate your baseline and you will not earn free credits. The February 2026 smart meter compensation rules apply if your supplier is dragging its feet on getting yours fixed.
- When you get the day-before email, open your battery app (we ship with a simple scheduler) and add a one-hour force-charge slot that matches the session window. Set the charge power to your inverter limit (around 3kW for the Habo unit).
- Leave the rest of your normal day-shifting schedule alone. Free Electricity Sessions sit on top of, not in place of, your overnight Octopus Go cheap charge.
- Check the Octoplus dashboard within two weeks. The credit appears as a separate line item, not as a unit rate change.
What about EV owners?
If you have an EV and a home charger, plug in and start a session-aligned charge as well. The 7kW that an EV pulls is a far bigger free-energy capture than the 3kW the battery can absorb. Intelligent Octopus Go customers should note that smart-scheduled EV charging during a Free Electricity Session still counts towards the 6-hour Intelligent Octopus Go cap, although the cost is offset by the free credit. We still recommend running the battery force-charge in parallel because the two devices charge from different circuits and do not compete.
What about export tariffs and solar?
Households with solar should think about this carefully. If your solar is exporting to the grid under a fixed Smart Export Guarantee rate (typically 15p), the value of an exported kWh during a session is unchanged. The value of an imported kWh into the battery is free. So during a session, set the battery to grid-charge rather than solar-charge, and let solar continue to export at SEG rates. You earn on the export and save on the import at the same time. Octopus Flux customers on a peak-rate export can model the same logic but with a higher export rate.
Where Habo Energy fits
Habo's 11.5kWh all-in-one battery ships pre-configured for Octopus Go and Economy 7, and the scheduler accepts a second daily charge window for exactly this use case. The inverter is rated below 3.6kW so installation is a fast G98 notification, with a single MCS-certified engineer visit. Total installed price is £4,599 with 0% VAT applied. Free Electricity Sessions are a small bonus on top of the headline arbitrage saving, but they are a clean illustration of the broader point: a battery is the household device that turns the GB grid's increasingly weird daily price shape into money in your pocket.
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