Tesla Powerwall 3
13.5 kWh of storage, an integrated solar inverter and whole-home backup, fitted by a Tesla certified installer.
Tesla certified installer
- 13.5 kWh
- usable capacity
- 11.5 kW
- continuous power
- 10 years
- warranty
What it costs to have one fitted
0% VAT until March 2027
Installed price covers the unit, mounting, a dedicated circuit, DNO application, commissioning and the app set up on your phone. Includes the Backup Gateway.
What moves it: how far the unit is from the consumer unit, whether the board has a spare way, whether a gateway is going in for backup, and whether it is going on a wall or standing on the floor.
We give you a figure at the visit and put it in writing. Finance is available; Newpower Advanced Ltd is a credit broker, not a lender (FCA FRN 1037988).
Why the Tesla Powerwall 3
One box does the lot
The solar inverter is built in, so on a new solar install there is no separate inverter to buy, mount or warranty. On a battery-only install it simply charges from the grid.
Whole-home backup
With the Backup Gateway the whole house keeps running in a power cut, not just a few circuits. 11.5 kW continuous is enough to run a heat pump, an oven and an EV charger at the same time.
The Tesla app
Storm Watch charges the battery ahead of severe weather, time-based control follows your tariff windows, and the app shows every watt of solar, home, grid and battery in real time.
Two ways to fit a Powerwall 3
With new solar
The panels connect straight into the Powerwall's own inverter. Fewer boxes on the wall, one warranty, and the neatest install we do. This is the route for most new solar customers.
Added to existing solar
Your current inverter stays and the Powerwall is AC-coupled alongside it. Works with any brand and age of solar system; we check the existing install for safety at the survey.
Full specification.
| Usable capacity | 13.5 kWh |
|---|---|
| Continuous power | 11.5 kW |
| Solar inverter | Integrated, 6 MPPT inputs, up to 20 kW DC of solar |
| Backup | Whole-home with Backup Gateway (included) |
| Expandable | Up to 4 Powerwall 3 and 3 Expansion units, 7 in total |
| Chemistry | Lithium iron phosphate (LFP) |
| Mounting | Wall or floor, indoor or outdoor |
| Dimensions | 1105 × 609 × 193 mm |
| Weight | 130 kg |
| Warranty | 10 years |
| App | Tesla app (iOS and Android) |
| Tariff control | Time-based control; Tesla Energy Plan and Octopus tariffs supported |
| VAT | 0% until March 2027 |
Manufacturer specifications. Where we could not source a figure we left the row out rather than guess at it.
Tesla Powerwall 3 vs Duracell Energy vs Fox ESS battery
An honest comparison. We fit all three.
| Tesla Powerwall 3 | Duracell Energy | Fox ESS battery | |
|---|---|---|---|
| Capacity | 13.5 kWh | Modular | Stackable |
| Continuous power | 11.5 kW | Varies by model | Set by the inverter |
| Solar inverter | Built in | Separate hybrid inverter | Fox ESS hybrid |
| Whole-home backup | Yes, gateway included | Optional, with a gateway | No, essential circuits (EPS) |
| Add capacity later | Add a second unit | Add modules | Add modules |
| Warranty | 10 years | Manufacturer warranty | Manufacturer warranty |
Powerwall 3 is the one to pick if you want the highest power output, the simplest new-solar install and backup for the whole house. If you want to start smaller and add capacity later, or want the lowest cost per kWh, Duracell or Fox ESS usually win. We fit all three and will show you the numbers for your usage rather than push one.
Tariff pairing: Octopus Flux or Intelligent Octopus Go
With solar, Octopus Flux pays a high export rate in the evening peak, so the Powerwall sells what you do not need across the late-afternoon peak. Without solar, Intelligent Octopus Go fills it overnight at the cheap rate and the house runs on that all day. We program the schedule before we leave, and the Tesla app lets you change it.
Smart energy tariffs explainedWhy Newpower
- Rated 4.7 on Trustpilot
- MCS NAP-75287 · TrustMark 3658638 · RECC 00078420
- MCS certified installation, and one number to ring afterwards
- A price in writing before you commit to anything
Questions about the Tesla Powerwall 3.
How much does a Tesla Powerwall 3 cost installed?
It is zero-rated for VAT until March 2027, with or without panels. With new solar the price turns on how many panels go up; added to an array you already have, it is priced as a battery-only install. The Backup Gateway is the other variable, and it is only worth it if you actually want the house to stay on in a cut. We give you the figure at the visit and put it in writing.
Will it run my whole house in a power cut?
Yes. The Backup Gateway sits between the meter and the house and disconnects from the grid within a fraction of a second, so the whole house runs from the Powerwall. 11.5 kW continuous covers most homes including a heat pump; a very large home may need two units.
Do I need solar panels to have a Powerwall?
No. On a time-of-use tariff it charges overnight at the cheap rate and runs the house through the day. The built-in solar inverter is simply unused until you add panels, which you can do later without changing anything.
Can I add a Powerwall 3 to my existing solar?
Yes. It is AC-coupled alongside your existing inverter, so it works with any brand. If your inverter is near the end of its life we can move the panels onto the Powerwall's own inverter instead.
What does Tesla certified installer mean?
Newpower has been trained and approved by Tesla to design, install and commission Powerwall systems. Only certified installers can supply a Powerwall, register its warranty and access Tesla's installer support.
How long does the install take?
A Powerwall with the Backup Gateway is typically a day on site. The G99 application to the network operator is made beforehand and takes a few weeks; we submit and chase it.
Get a price for a Tesla Powerwall 3.
We come and look, tell you whether this is the right unit for your house, and put the price in writing.