Tesla Powerwall 3 residence battery now on sale

  • Tech powerhouse Tesla has launched its latest home battery, the Powerwall 3
  • The kit doesn’t come cheap – but it has impressive energy storable abilities 

Tesla has launched its Powerwall 3 home battery in the UK – but how does it work, and can it really save you £1,450 a year on your energy bills?

The Tesla Powerwall is a large rechargeable battery that mounts to the wall of a home, and the third edition of the battery is now available for sale.

The Powerwall can store electricity for use at a later point, with households able to use the device to save money on their energy bills.

This is everything you need to know about how the Tesla Powerwall 3 works.

Powered up: The Tesla Powerwall's sleek exterior hides a battery that can power most homes

Powered up: The Tesla Powerwall’s sleek exterior hides a battery that can power most homes

How does a Powerwall 3 work?

The Powerwall lets households store solar-powered electricity, either through solar power or for use with time-of-use energy tariffs.

These tariffs are special energy deals that charge less for electricity used in off-peak periods – often at night.

Homes with a large battery fitted, such as the Powerwall, can take advantage of this by charging up when electricity is cheap, then using that power when electricity is more expensive.

Another perk of the Powerwall is that it automatically detects power cuts and kicks in.

When extreme weather is forecast, the Powerwall 3 will charge to its maximum. That energy can then be used to power household appliances in the case of a power cut.

The device can still work when submerged in 60cm of water, and in temperatures from -20c to 50c.

How much electricity can a Powerwall 3 store?

The Powerwall 3 can store up to 13.5kWh of electricity when new Tesla says, falling to 9.45kWh after 10 years.

The average home uses around 7.3kWh of electricity a day, according to energy regulator Ofgem, meaning one Powerwall should comfortably be able to power most homes on a full charge.

However, more than one Powerwall can be fitted for homes with very high electricity needs.

Part of the background: The Powerwall can be fitted to the exterior of most properties

Part of the background: The Powerwall can be fitted to the exterior of most properties

How much does it cost?

The typical cost is £6,300 for one Powerwall 3.

This is made up of £5,500 for one Powerwall and another £800 for the Tesla Gateway, which allows energy metering and management and the ability for the Powerwall to kick in during a powercut.

But the overall cost will vary, and customers can get more accurate quotes on the Tesla website.

Crucially, the prices above do not include installation costs or VAT, meaning the price to fit one Powerwall is likely to be in the £7,000 to £8,000 region.

How much can it save me on my energy bills?

Tesla claims the Powerwall 3 can save the average home £1,450 a year on their energy bills.

That is a significant saving, as the typical home currently pays £1,690 a year for energy, falling to £1,568 a year from 1 July.

That means a home with a Powerwall could spend just £118 on energy bills a year from 1 July.

However, to achieve the £1,450 saving a home would need to have solar panels installed.

Customers also need to factor the installation costs of the Powerwall.

A £7,000 bill to fit the Powerwall would mean a cost of £700 per year for the typical home, which reduces Tesla’s claimed savings to around £750 a year at current energy prices.

Is the Powerwall 3 an EV home charger?

No, the Powerwall 3 is a storage energy unit, not a home charger. But you can utilise Powerwall to make your home charging more efficient, which means you can benefit from it even if you don’t drive a Tesla EV.

How does Powerwall benefit my EV charging?

If you’ve got a smart wallbox home charger installed then you can schedule charging when you’re home’s exclusively using excess solar energy, which will reduce environmental impact and save you money.

Also usefully the Powerwall 3 has an integrated solar inverter which will convert the electricity from DC to AC – which is used for Type 2 EV home charging.

How much money will it save me on charging?

The exact amount will depend on the EV you have and how long it’s on charge for.  

In the same way you charging off-peak saves you money, charging using your Powerwall’s stored energy will significantly reduce the cost of your home charging.

Will it make my EV greener?

If you charge using only stored energy from your solar panels, then you’ll be powering your EV with clean renewable energy which does make your EV ‘greener’.