The Powerwall 3 is a 13.5kWh home battery with a solar inverter built into it, rated at up to 11.04kW on grid and in backup, and Tesla lists it on its own UK site at £5,975 for a unit with a Gateway. That price excludes VAT, delivery and installation, and it is not what lands on your driveway. Tesla does not install it. A Tesla Certified Installer quotes the finished job, and the gap between the list price and the installed price is where the whole decision sits.
Every figure below was checked on 25 September 2026 against Tesla's own UK product and pricing pages, the Tesla Powerwall Warranty for the European Warranty Region (Rev. 1.16, effective 3 December 2025), HMRC VAT Notice 708/6, National Grid Electricity Distribution's G99 guidance, and Ofgem's published price cap. Where Tesla's marketing page and Tesla's warranty document say different things, the document is quoted, because that is the part you can hold someone to.
Compare it against two more quotes covering the same usable capacity and the same inverter rating before you commit. Quotes come from MCS certified installers covering your area.
Get a Quote →What Tesla actually charges, and what the asterisk hides
Tesla publishes four UK hardware prices on its Powerwall quote-request page, and they are the only manufacturer-published battery prices you will find for a British home. As at 25 September 2026 they read:
| Configuration | Tesla UK list price |
|---|---|
| 1 Powerwall 3 without Gateway | £5,000 |
| 1 Powerwall 3 with Gateway | £5,975 |
| 1 Powerwall 3 without Gateway, plus 1 Expansion unit | £9,000 |
| 1 Powerwall 3 with Gateway, plus 1 Expansion unit | £9,975 |
Tesla's footnote is one line and it carries most of the weight: the prices do "not include VAT, delivery, installation, or other costs and fees", and "Final price will be provided by a Certified Installer". A second note sits against the cheapest option: the £5,000 no-Gateway configuration "Requires Tesla Remote Meter (TRM), not included in price". So the headline number is not a system, and the second-cheapest number is the first complete one.
The VAT half of that footnote is worth reading carefully, because for most British homeowners it does not mean what it appears to mean. Tesla is quoting a hardware price to the trade, so it strips VAT out. When a Certified Installer supplies and fits that battery in a home, HMRC's rules zero rate the whole supply until 31 March 2027, so there is no VAT to add back on. The people it genuinely costs are those buying a unit on its own to fit later, which is standard rated at 20%. The VAT position on solar and storage is set out in full on its own page, and it is the single most misquoted number in British solar.
What the finished job costs is a separate question with no published answer, because Tesla does not set it. Installers do, and they are pricing scaffolding, an electrician, a Gateway or a Remote Meter, a grid application and their own margin on top of the unit. Treat the list price as the floor of the hardware line on your quote, not as the quote.
The specification, and the one number that surprises people
The Powerwall 3 holds 13.5kWh and delivers up to 11.04kW, on grid and on backup alike, which is roughly twice the continuous output of the Powerwall 2 it replaced. Tesla's UK spec table gives the Powerwall 2 as 5kW continuous with a 7kW backup peak; the Powerwall 3 does 11.04kW in both modes, with a 185A locked rotor rating for starting motors against the Powerwall 2's 106A. If you have ever watched a heat pump or a well pump trip a smaller battery on startup, that second figure is the one that matters.
The headline change in the Powerwall 3, released in September 2023, is that the solar inverter moved inside the battery. Tesla quotes 97.5% solar-to-grid efficiency and, on the EMEA unit, three solar inputs with maximum power point trackers. That is worth stating plainly because the American product is commonly described as having six, and a homeowner planning four roof orientations off a US spec sheet will be disappointed. Three MPPTs is generous for a British house, where two pitches is the normal case, but it is three.
| Specification | Powerwall 3 | Powerwall 2 |
|---|---|---|
| Energy capacity | 13.5kWh | 13.5kWh |
| On-grid power | Up to 11.04kW | 5kW continuous |
| Backup power | Up to 11.04kW | 7kW peak |
| Motor start (locked rotor) | 185A | 106A |
| Integrated solar inverter | Yes, 3 MPPT inputs, 97.5% solar to grid | No |
| Size and weight | 1,105 x 609 x 193mm, 130kg | 1,150 x 753 x 147mm, 114kg |
| Units per system | Up to 4, plus up to 40.5kWh of Expansion per unit | Up to 10 |
| Install temperature | -20°C to 50°C, flood resistant to 0.6m | -20°C to 50°C |
| Warranty | 10 years | 10 years |
Because the inverter is inside the battery, a Powerwall 3 usually replaces the separate string or hybrid inverter you would otherwise be quoted, rather than sitting alongside it. That changes what you are comparing. A quote built around a standard hybrid inverter plus a separate battery is not the same shape of system, and the honest comparison is total installed cost against total usable capacity and output, not battery against battery. The same caution applies when a quote pairs panels with SolarEdge optimised hardware, which solves the shading problem a different way and prices differently again.
The UK gets an 80% warranty. Most pages about it say 70%
Tesla's European warranty document splits Europe into two tiers, and the United Kingdom is in the better one. For Powerwalls installed in Austria, Belgium, France, Germany, Ireland, Luxembourg, the Netherlands, Switzerland or the UK, the guaranteed energy retention is 80% at 10 years following the initial installation date. For Powerwalls installed in Italy, Spain, Malta, Portugal or Slovenia, the same document gives 70%.
That is a real difference, and it is widely got wrong. The 70% figure circulating on British pages comes from Tesla's American and Australian warranty documents, which do use 70%. The document that governs a battery fitted to a house in Britain is the European one, Rev. 1.16, and it says 80%, expressed as a percentage of the 13.5kWh rated capacity. On a 13.5kWh battery, the difference between a 70% floor and an 80% floor is 1.35kWh of guaranteed capacity in year ten, for free, purely because of where you live.
Tesla also warrants that the Powerwall "will be free from defects for ten years following its initial installation date" and that it "will have an energy capacity of 13.5 kWh on its initial installation date". The warranty transfers: "A subsequent owner of the Powerwall who provides proof of ownership is also entitled to make Warranty claims", which matters if you are weighing what solar and storage do to a house sale.
The throughput cap that only bites if you use it a certain way
The retention promise comes with an operating limitation, and Tesla splits it by what you do with the battery. Use it for solar self-consumption or time-based control, and backup, and the limitation is "Unlimited cycles". Use it for anything else, or for "any combination of applications that includes one not listed above", and the cap is 37.8MWh of aggregate throughput, measured at the battery AC output.
Work that out and it is about 2,800 full cycles of a 13.5kWh battery, which is roughly seven years and eight months at one complete charge and discharge a day. So the cap lands well before the ten year date for anyone who hits it. The reassuring part is that the three named applications cover what almost every British household actually does: storing solar, shifting load onto a cheap overnight rate, and holding charge for a power cut. The three named uses carry unlimited cycles, so a normal home installation is not in throughput-capped territory at all. It is worth knowing the boundary exists before somebody sells you on a use that sits outside it.
This is a gentler version of the same structure that catches people out elsewhere. Fox ESS caps its batteries by throughput in every case, at a level that binds before the headline date, and attaches its free warranty extension to a registration deadline counted from the date of manufacture. Tesla's cap is narrower and its headline term is not conditional in the same way, which is a genuine point in its favour.
The exclusion that turns ten years into four
Tesla's warranty requires the Powerwall to stay connected to the internet and registered, and says so in terms. If your Powerwall "is not connected to the Internet for an extended period, or has not been registered with Tesla", Tesla writes that "we may not be able to honor your full ten year warranty". The floor it commits to instead is explicit: "we will always honor your warranty for at least four years following the date your Powerwall was installed for the first time".
Four years, not ten, if the unit sits offline. This is the same condition SolarEdge attaches to its inverters, and it is becoming standard across connected home energy hardware. If your broadband is unreliable, or the battery is going in a garage or outbuilding at the edge of the signal, treat the connection as part of the installation rather than an afterthought.
Two other exclusions are worth knowing. The warranty does not cover defects resulting from installation, commissioning, modification or repair "performed by anyone other than the Tesla or a Tesla certified installer", so using a cheaper non-certified electrician for later work is expensive. And it excludes "removal and reinstallation of your Powerwall at a location other than the original installation location, without the express written consent of Tesla", so taking it with you when you move needs Tesla's agreement in writing first.
One more UK-only clause
The warranty's United Kingdom appendix gives a 30 day rejection right under the Consumer Rights Act 2015, with Tesla barred from using refurbished parts for a repair. Read the opening condition, though: it applies "IF YOU ARE A CONSUMER (AS DEFINED IN THE CONSUMER RIGHTS ACT 2015) AND YOU PURCHASED YOUR POWERWALL DIRECTLY FROM TESLA". Most British buyers do not. They buy from a Certified Installer, which means their contract, and their Consumer Rights Act claim, is against that installer rather than Tesla. That is not a loss, it is just a different counterparty, and it is another reason the installer you choose matters at least as much as the box.
An 11.04kW battery needs G99 approval before it goes in
A Powerwall 3 cannot be fitted under the notify-afterwards route. It needs prior approval from your network operator. National Grid Electricity Distribution states the threshold plainly: "Generation installations in excess of 16A (3.68kW) per phase must comply with Engineering Regulation (EREC) G99." A Powerwall 3 at 11.04kW on a single phase 230V supply works out at about 48A, which is three times the limit.
The consequence is a timing one rather than a cost one. Under G98, an installer notifies the network operator within 28 days of commissioning and the job simply happens. Under G99, an application goes in and is approved before anything is energised, and that approval takes as long as it takes. National Grid's own G99 procedures cover "generation and energy storage installations" together, so a battery counts towards the threshold in its own right. The full picture on both routes, including the fact that the threshold is measured on total aggregated output rather than on panel kWp, is on our G98 and G99 explainer.
Two practical points. Network operators differ in process even though the thresholds are national, so what your installer has to file depends on whose wires you are on. And a Powerwall 3 can be configured to limit its export, which is sometimes how an installer gets a constrained connection approved, so ask what output your approval is actually for rather than assuming the full 11.04kW.
What it is worth, on 2026 electricity prices
A home battery earns its keep on the gap between what you avoid paying and what you would have been paid for exporting. Ofgem's price cap for 1 October to 31 December 2026 puts electricity at 26.32p per kWh on a direct debit average, with a 54.83p daily standing charge, up from 26.11p in the quarter to 30 September. Typical Smart Export Guarantee rates sit far below that, so every kilowatt hour the battery lets you use at home instead of exporting is worth several times more than the same unit sold to the grid.
There is a change this winter that most battery pages have not caught up with. VAT on domestic electricity in Great Britain drops to zero from 1 October 2026 to 31 March 2027, under a temporary zero rate announced on 21 July 2026 and published by HMRC on 8 September 2026. The government expects it to take around £45 off the annual price cap. Two details matter for solar owners. It applies to England, Wales and Scotland only: HMRC states that "In Northern Ireland, the rate of VAT on supplies of qualifying electricity will remain unchanged" at the reduced rate. And it is temporary, reverting on 1 April 2027, which is the day after the 0% rate on installing solar and batteries also ends.
A cheaper unit rate slightly weakens the case for storage, because the thing you are avoiding costs less. It is a small effect at 5% on a rate that rose anyway, and it reverses in April. But it is the kind of moving part that makes a fixed payback figure worth distrusting. The way to sanity check any battery quote is to take your own annual consumption, work out how much of your generation you currently cannot use, and price that against what a unit of electricity actually costs you rather than against a national average. The arithmetic behind that, and why self-consumption beats export on almost any current tariff, is set out on our Smart Export Guarantee rates page.
For the general case, rather than the Tesla case, our guide to solar battery storage in the UK covers sizing, usable versus rated capacity and whether a battery is worth adding at all. Read that first if you have not decided on storage in principle. If you have, and you are choosing between brands, the same warranty-document discipline applied here is worth applying to Sunsynk and to whatever else lands on your quote.
Where Tesla fits, honestly
The Powerwall 3 is expensive per kilowatt hour and strong per kilowatt. If what you want is backup that runs a real house rather than a fridge and a router, 11.04kW with a 185A motor start is genuinely hard to match, and the integrated inverter removes a box and a failure point. If what you want is the cheapest usable storage to soak up a cheap overnight tariff, there are batteries that cost considerably less per kWh and you are paying for output you will not use.
Tesla says over one million Powerwalls have been installed globally, representing 6.7GW of battery power and 17.3TWh delivered. That fleet size is the real argument for it: a large installed base, a UK support line, a national certified installer network and a warranty document that is clear enough to argue with. None of that tells you it is the right battery for your house. Three itemised quotes covering the same usable capacity will.
Ask installers to quote the same usable capacity and the same backup output, with the battery, inverter, grid application and warranty terms listed as separate lines.
Get a Quote →Frequently asked questions
Tesla lists the hardware at £5,975 for one Powerwall 3 with a Gateway, or £5,000 without one, as at 25 September 2026 on its own UK quote-request page. Adding one Expansion unit takes those to £9,975 and £9,000. Tesla's footnote says the prices do not include VAT, delivery, installation or other costs and fees, and that the final price is provided by a Certified Installer, so the installed cost is higher and Tesla does not publish it. The £5,000 option also requires a Tesla Remote Meter that is not included in the price, so it is not a complete system.
80%, not the 70% widely quoted. Tesla's Powerwall Warranty for the European Warranty Region, Rev. 1.16, effective 3 December 2025, splits Europe in two. Powerwalls installed in Austria, Belgium, France, Germany, Ireland, Luxembourg, the Netherlands, Switzerland or the UK retain 80% of the 13.5kWh rated capacity at 10 years from the initial installation date. Powerwalls installed in Italy, Spain, Malta, Portugal or Slovenia retain 70%. The 70% figure on many British pages comes from Tesla's American and Australian warranty documents, which do not govern a UK installation.
Only for uses outside the three named applications. Tesla's European warranty gives "Unlimited cycles" where the Powerwall is used for solar self-consumption or time-based control, and backup. For any application not listed, or any combination including one not listed, the operating limitation is 37.8MWh of aggregate throughput measured at the battery AC output. That is roughly 2,800 full cycles of a 13.5kWh battery, or about seven years and eight months at one cycle a day, so it would bind before the ten year date. Storing solar, shifting load onto a cheap overnight rate and holding charge for an outage all fall inside the unlimited-cycle applications.
Effectively yes, if you want the full ten years. Tesla's warranty states that if the Powerwall is not connected to the internet for an extended period, or has not been registered with Tesla, "we may not be able to honor your full ten year warranty", because Tesla cannot deliver remote firmware upgrades. It commits to a floor instead: "we will always honor your warranty for at least four years following the date your Powerwall was installed for the first time". So an offline or unregistered unit drops from a ten year warranty to a four year one.
G99, with approval before installation. National Grid Electricity Distribution states that generation installations in excess of 16A (3.68kW) per phase must comply with EREC G99. A Powerwall 3 rated at up to 11.04kW on a single phase 230V supply is about 48A, roughly three times the threshold, so the connect-then-notify G98 route is not available. Your installer applies to the network operator and waits for approval before energising anything, rather than notifying within 28 days afterwards as they would under G98. National Grid's G99 procedures cover generation and energy storage installations together, so the battery counts in its own right.
Not on a supply-and-install job in a home before 31 March 2027. HMRC's VAT Notice 708/6 zero rates the installation of specified energy-saving materials until 31 March 2027, and since 1 February 2024 that has included electrical storage batteries in residential accommodation, covering retrofits to an existing microgeneration system, standalone batteries charged from the grid, and hybrids of the two. From 1 April 2027 it reverts to the reduced rate of 5%, not to 20%. Buying a Powerwall on its own from a retailer without installation is standard rated at 20%, which is why Tesla's hardware list price is quoted excluding VAT.
Three, on the unit sold in the UK and the rest of EMEA. Tesla's UK specification table lists "3 solar inputs with Maximum Power Point Trackers" and a solar-to-grid efficiency of 97.5%. American coverage frequently cites six MPPTs, which does not describe the unit fitted in Britain, so plan roof orientations against the three-input figure. Three is ample for the typical British two-pitch roof but it is a real constraint on a complex roof with four or more usable aspects.
Not without Tesla's written agreement. The warranty's general exclusions cover "removal and reinstallation of your Powerwall at a location other than the original installation location, without the express written consent of Tesla", and doing it anyway may void the warranty. It also excludes work performed by anyone other than Tesla or a Tesla certified installer. If instead you leave it behind, the warranty follows the battery: Tesla states that a subsequent owner who provides proof of ownership is entitled to make warranty claims.
Sources checked live on 25 September 2026: Tesla United Kingdom Powerwall product and quote-request pages; Tesla Powerwall Warranty (European Warranty Region), Rev. 1.16, effective 3 December 2025; HMRC VAT Notice 708/6; HMRC policy paper, Temporary zero rate of VAT in Great Britain for domestic electricity, published 8 September 2026; Ofgem energy price cap unit rates; National Grid Electricity Distribution G99 guidance.