What Octopus offers: the Nook battery range
At its Energy Tech Summit on 22 June 2026, Octopus announced its first own-brand home batteries and said it is the first major UK energy supplier to offer its own battery range directly to customers (Octopus launch announcement, 22 June 2026). There are two products:
- Octopus Nook Cube. A shoebox-sized 2kWh battery that plugs into a standard socket and is controlled through the Octopus app. Extra units can be added for up to 10.5kWh. Octopus says it is designed for renters and apartment dwellers.
- Octopus Nook Colossus. A wall-mounted, engineer-installed battery for homeowners, in 5kWh and 10kWh models that stack up to 30kWh.
Octopus says both are compatible with solar panels, both have a 12-year warranty, and both will be available to Octopus customers in the UK, Germany, France, Italy and Spain "from next year", which means 2027. The announcement gives no price for either product and no launch month (Octopus launch announcement). We do not estimate Nook prices until Octopus publishes them.
| Nook Cube | Nook Colossus | |
|---|---|---|
| Type | Plug-in, standard socket | Wall-mounted, engineer-installed |
| Capacity | 2kWh, add units up to 10.5kWh | 5kWh or 10kWh, stack up to 30kWh |
| Aimed at | Renters and apartment dwellers | Homeowners |
| Warranty | 12 years | 12 years |
| On sale | 2027, Octopus customers | 2027, Octopus customers |
| Price | Not published | Not published |
Source for every row: Octopus launch announcement, 22 June 2026, checked 28 October 2026.
Go deeper:
- Octopus Nook home battery: should you wait for 2027?
- Octopus plug-in home battery: what the Nook Cube can and cannot do
- Octopus Nook vs Habo Energy: what is and is not known about price
Which Octopus tariffs suit a battery
A battery saves money by charging when electricity is cheap and powering the home when it is dear. Octopus has several tariffs with cheaper periods, but who can join each one differs. This is the overview. For a step-by-step choice, see our guide to choosing an Octopus tariff for a battery.
| Tariff | Cheaper period (Octopus) | Who Octopus says it is for | Source |
|---|---|---|---|
| Octopus Go | 00:30 to 05:30 every night | Joining steps list an electric car you charge at home and a smart meter | Octopus Go |
| Intelligent Octopus Go | Six hours for the home, 23:30 to 05:30 | A compatible electric car or charger | Intelligent Octopus Go |
| Cosy Octopus | Three cheaper periods a day | Homes with a heat pump | Octopus tariffs |
| Octopus Flux | 02:00 to 05:00 cheap, 16:00 to 19:00 peak | Homes with solar panels and a home battery | Octopus Flux |
| Agile Octopus | Half-hourly prices tied to wholesale, capped at 100p/kWh | Homes that can shift a big chunk of use ("great if you WFH or have a home battery") | Agile Octopus, Octopus tariffs |
All checked 28 October 2026. Octopus changes tariffs often, so check the linked page before you switch.
- Octopus Go. The tariff our savings maths uses. Octopus's own joining steps list an electric car you charge at home (Octopus Go), so check you qualify before you plan around it. The current fixed version, Octopus Go 12M Fixed, has a £50 exit fee (Octopus product data).
- Intelligent Octopus Go. Six cheap hours for the whole home each night if you have a compatible EV or charger. Read how the 6-hour cap affects a home battery.
- Cosy Octopus. The heat pump tariff. See Cosy Octopus and home batteries.
- Octopus Flux. Import and export tariff built for solar plus battery homes. See Octopus Flux in 2026.
- Agile Octopus. Prices change every half hour and are set a day ahead. Octopus's joining steps list being an Octopus customer and a smart meter (Agile Octopus). Savings vary day to day, so we do not publish a fixed figure for it.
Comparing beyond Octopus? See the best tariffs for battery storage in the UK.
Saving Sessions: extra rewards, not a tariff
Saving Sessions are an Octoplus rewards scheme rather than a tariff. In Power Down sessions you earn Octopoints for using less at busy times, and Power Up sessions, which replaced Free Electricity sessions, reward you for using more when there is plenty of renewable power. You opt in to each session, and you need Octoplus, Direct Debit or smart prepay, and a smart meter sending half-hourly readings. Octopus says both session types now form part of NESO's Demand Flexibility Service (Octopus Saving Sessions). A charged battery can cover a Power Down session without you switching things off. Read our full guide to Octopus Saving Sessions with a home battery.
What you can buy today instead of waiting for the Nook
The Nook is a 2027 product with no price. If you own your home and want a battery on your consumer unit now, it needs to be wired in by an electrician. Habo installs the 5 kWh EcoFlow STREAM from £2,499 fully installed, electrician-wired to the consumer unit.
- Capacity and expansion: 5,024 Wh per unit, expandable with STREAM Expansion Battery 5000 packs to 15kWh per unit (EcoFlow UK STREAM AC 5000).
- Wired, not plugged in: EcoFlow says in the UK the STREAM must be installed into the distribution board by a professional installer or electrician, and should not be connected to a household socket to feed power in (EcoFlow UK).
- G98, not G99: a single STREAM AC 5000 has a maximum grid-connected output of 2,500W (3,000W with an Expansion Battery) (EcoFlow UK), under the 3.68kW per phase limit below which EREC G98 applies (Energy Networks Association). See G98 vs G99.
- Warranty: 10 years from EcoFlow (EcoFlow warranty policy).
- 0% VAT until 31 March 2027: HMRC zero-rates installing a standalone battery that stores electricity from the grid in a home, then the rate goes to 5% from 1 April 2027 (HMRC VAT Notice 708/6). See VAT on home batteries.
How much it could save, as a savings-account rate
The fairest way to judge a battery is to ask what interest a savings account would need to pay to match it. Divide the yearly saving by the installed cost.
Best case on Octopus Go 12M Fixed, a 5 kWh battery saves up to about £453 to £527 a year. On £2,499 installed, that is like a savings account paying about 18.1% to 21.1% a year (£453.49 ÷ £2,499 and £526.76 ÷ £2,499). Turned round, best-case payback is about 4.7 to 5.5 years. Real savings will be lower. On a flat rate there is no saving.
How we worked it out: Octopus Go 12M Fixed (product GO-FIX-12M-26-10-14), direct debit, night rate 9.4p/kWh, day rate 35.293p/kWh (East Midlands) to 39.3081p/kWh (Merseyside and North Wales), checked 28 October 2026 (Octopus product data, Octopus Go). EcoFlow does not publish a round-trip efficiency for the STREAM, so we assume 90%: to deliver 5 kWh at the day rate you buy 5.556 kWh at night. Low: (5 × 35.293p) − (5.556 × 9.4p) = 124.24p a day, £453.49 a year. High: (5 × 39.3081p) − (5.556 × 9.4p) = 144.32p a day, £526.76 a year. This is a ceiling: it assumes one full 5 kWh cycle every day, all used at the day rate. Full workings are on our homepage, the rate comparison is in home battery vs savings account, and you can check your region.
Frequently asked questions
It has announced one. The Nook Cube (2kWh plug-in, up to 10.5kWh) and Nook Colossus (5kWh or 10kWh wall-mounted, up to 30kWh) come with a 12-year warranty and go on sale to Octopus customers from 2027, with no price published (Octopus announcement).
Not for Octopus Go, Intelligent Octopus Go, Cosy or Agile, where a battery can charge from the grid in the cheaper period. Octopus Flux does need solar panels and a home battery (Octopus Flux). More in battery storage without solar.
It depends on whether you have an EV, a heat pump or solar. Our Octopus battery tariff guide takes you through it.
Not automatically. EcoFlow says that in an outage the STREAM's grid-connected port stops and power comes only from its AC outlet, to loads connected there (EcoFlow UK). See home battery backup power.
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Habo installs a 5 kWh EcoFlow STREAM from £2,499 fully installed, electrician-wired to the consumer unit. Best case on Octopus Go, up to about £453 to £527 a year, like a savings account paying about 18.1% to 21.1% (how). Real savings will be lower. Join the install waitlist. Nothing to pay today.
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