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Tesla Powerwall Battery Cost in 2024

Written By:

Reviewed By:

Ollie Smith

Updated on

The Tesla Powerwall is one of the most popular solar battery storage systems for homes. You can install a Powerwall as a stand-alone battery or combined with solar panels.

The energy storage capacity of a Tesla Powerwall is 13.5 kilowatt-hours (kWh). If you add the battery to a solar panel system, you can store electricity during the day and use it at night when energy is more expensive. The Powerwall can also be used as a backup energy source during blackouts:

  • The Tesla Powerwall stores solar energy to be used at any time, including cloudy days and night time.
  • A single Powerwall can store 13.5 kilowatt-hours (kWh), enough to power a typical UK home for more than 24 hours.
  • The installed price of a Powerwall ranges from £9,000 and £12,000, which means you are paying less than £900 per kWh of storage capacity.
  • The Powerwall is exempt from 20% VAT if installed along with solar panels.
  • Without a battery, excess production from your solar panels is exported to the grid at low tariffs.  With a battery like the Powerwall, you save the full value of each kWh generated.
  • In some cases, a Powerwall can increase the savings of a home solar system by over £1,000 per year.
  • Tesla offers a 10-year warranty.

The Tesla Powerwall is one of the most popular energy storage systems for homes. You can install a Powerwall as a stand-alone battery or combined with solar panels, and both configurations can provide electricity during power outages.

  • A typical UK home uses 2,700 kWh/year according to Ofgem, which means the average daily consumption is around 7-8 kWh.
  • The Tesla Powerwall can store 13.5 kilowatt-hours (kWh), enough to power a typical UK home for an entire day.

Backup power is not possible with stand-alone solar panels, since their electricity output is always changing based on sunlight conditions. For example, if a large cloud passes over your property, there is a notable drop in solar electricity output. On the other hand, a charged battery can provide a sustained power output even when solar panels are not productive.

Here we will discuss the typical cost of a Tesla Powerwall, and the scenarios where it can increase the savings achieved by solar panels. We will also review the technical specifications and features of the Powerwall, along with the warranty offered by Tesla.

How Much Does a Tesla Powerwall Cost in the UK?

According to the Tesla UK website, the Powerwall has a cost of £6,000 before delivery costs, installation labour and VAT. You also need a Tesla Gateway for energy management, which has a price of £900. Considering both components, the total equipment cost is £6,900.

  • A single Tesla Gateway can be used with multiple Powerwalls (up to 10).
  • This means two units will cost you £12,900 including the Gateway, while three units will cost £18,900.

You can contact a Tesla Certified Installer by submitting your personal information, and they will provide a quote that includes all installation costs and applicable taxes. If you install a Tesla Powerwall by 31 December 2023, you can qualify for a £350 rebate.

The installed price of a Tesla Powerwall varies by provider and location, but you can expect to pay between £9,000 and £12,000 in total. Energy storage systems are exempt from the VAT when installed along with solar panels, but stand-alone batteries are subject to a 20% VAT. If you install a stand-alone Powerwall, the VAT can range from £1,800 to £2,400.

The Tesla Powerwall offers a high energy storage capacity with respect to its cost: you can expect an installed price below £900 per kWh of storage capacity. Some competing battery systems exceed £1,200 per kWh.

Does the Tesla Powerwall Qualify for Incentives in the UK

As mentioned in the previous section, the Tesla Powerwall is exempt for the 20% VAT if installed along with a solar panels. Here are some additional incentives available in the UK:

Battery Storage IncentivesDescription
Smart Export Guarantee (SEG)The SEG is a net metering program. Electricity providers with at least 150,000 customers have a legal requirement to purchase excess solar energy from homeowners.
Most homeowners can get solar export tariffs of around 4.0-7.5 p/kWh, but some electric companies offer 12-15 p/kWh. You may qualify for SEG tariffs of up to 28-35 p/kWh if you own a home battery such as the Tesla Powerwall.
Home Energy Scotland Grant and Loan SchemeIf you install a home battery in Scotland, you can apply for the following incentives:A grant of up to £1,250An interest-free loan of up to £4,750
Assuming you buy a Tesla Powerwall for £10,000, you would only pay £4,000 upfront and £4,750 over time.
This incentive is only available if your battery bank is installed along with a package of energy efficiency measures. Stand-alone batteries are not eligible.
Tesla Powerwall RebateIf you install a Tesla Powerwall by 31 December 2023, you can apply for a £350 grant. If you install multiple Powerwalls, you can claim a grant for each unit. This incentive is not available for other battery brands.
Energy Company Obligation (ECO4) SchemeThe ECO4 Scheme is only available for low-income households with energy efficiency issues. Eligible properties may qualify for free energy upgrades, including solar panels and battery systems.

How Much Can I Save with a Tesla Powerwall?

The power bill savings offered by a Tesla Powerwall can vary widely depending on local tariffs and your energy usage habits. There are two main scenarios where a home battery can increase the savings normally achieved by solar panels:

1) When you are charged “Time-of-Use” or TOU tariffs

Some electric companies charge you a variable kWh price throughout the day. Grid electricity is cheaper when overall demand is low, and more expensive when demand is high. Domestic consumers are generally charged the highest TOU tariffs around the evening, when their energy usage reaches its highest point.

  • If you own a Tesla Powerwall and a solar PV system, you can store electricity during the day and use it during peak-tariff hours.
  • This way you achieve maximum savings per kWh generated.

As a quick example, assume your electric company has an off-peak tariff of 16 p/kWh and a peak tariff of 40 p/kWh. If you store 13.5 kWh in a Powerwall and wait until the peak-tariff hours, you save an extra 24 p/kWh. This can increase the savings of your solar power system by £3.24/day (or £1,182.60/year).

2) When you export most of your solar generation to the National Grid

If you consume solar energy directly, you save its full value. Considering that the UK has electric tariffs of over 30 p/kWh, the value of 1,000 kWh of solar energy can exceed £300. However, solar panels generate most of their electricity around noon, when most people are away from their houses. As a result, a large percentage of the electricity generated by solar panels is exported to the National Grid instead of being used directly.

As mentioned in the previous section, the Smart Export Guarantee (SEG) makes sure you are paid for this surplus energy. However, export tariffs are much lower than the retail kWh prices charged to you.

  • Some companies such as Octopus Energy, Good Energy and British Gas will pay you an SEG tariff of 15 p/kWh if you also become one of their customers. This means you must purchase electricity from them when your solar panels are not productive.
  • The best SEG tariffs that don’t require you to become a customer are offered by Scottish Power (12 p/kWh), SO Energy (7.5 p/kWh) and British Gas (6.4 p/kWh).

If you have a home battery, you may be able to access SEG tariffs of up to 28-35 p/kWh. There are energy companies who pay you very high rates if you can supply electricity to the grid during peak demand hours, typically after 4:00 PM.

  • You cannot access the highest SEG tariffs with solar panels alone, since they generate most of their electricity output around noon (before the peak-tariff schedule).
  • With a battery bank, you can store solar energy at noon and send it to the grid during the evening.

As a quick example, assume that a 5-kW solar system generates 4,500 kWh/year and its consumption is divided as follows:

  • 1,000 kWh are consumed directly, saving 35 p/kWh and £350 per year.
  • 3,500 kWh are exported to the grid at 5 p/kWh, earning £175 per year.
  • Adding direct savings and SEG income, the annual savings are £525 per year.

A 5-kW solar panel system has a typical cost of around £10,500, which means the payback period in this example is 20 years.

If you install a Tesla Powerwall, you can save the full value of 4,500 kWh. You can store excess solar energy instead of sending it to the grid at a low tariff, and this gives you two options:

  • Using stored energy directly and saving its full value.
  • Sending stored energy to the grid during peak hours and getting a high SEG tariff.

Using the Tesla Powerwall as described above, your power bill savings can increase to £1,575. The cost of your solar energy system increases to around £19,500 with a Powerwall included, but its payback period is reduced to 12.4 years.

Can a Tesla Powerwall Power an Entire Home During Blackouts?

The Tesla Powerwall can store up to 13.5 kWh, which is enough to power a typical UK home for more than 24 hours. Here is the typical electricity consumption of homes reported by Ofgem:

Home SizeTypical Annual ConsumptionAverage Daily Consumption
Flat or 1-bedroom house1-2 residents1,800 kWh4.93 kWh
2-3 bedroom house2-3 residents2,700 kWh7.40 kWh
4+ bedroom house4-5 residents4,100 kWh11.23 kWh

Note that the Powerwall has a maximum continuous power of 5 kW, and it can provide a peak power of 7 kW for short intervals. The total power input of the home devices connected to the Powerwall cannot exceed these values.

Tesla Powerwall: Technical Specifications and Main Features

Tesla has been upgrading the Powerwall since the first version of the product was launched in 2015. Here are the technical specifications of the Tesla Powerwall 2:

Tesla Powerwall 2 Specifications
Energy storage capacity13.5 kWhUp to 135 kWh if you combine 10 Powerwalls
Depth of discharge100%
Round-trip efficiency90%
Maximum power output5 kW continuous power7 kW peak power
ChemistryLithium nickel manganese cobalt oxide (NMC)
Size1150 mm x 753 mm x 147 mm Powerwall584 mm x 380 mm x 127 mm Gateway
Weight114 kg Powerwall11.4 kg Gateway
Operating Temperature-20°C to +50°C full range+10°C to +30°C optimal range
Warranty10 years

The Tesla Powerwall 2 is an AC-coupled battery. This means the unit uses its own inverter, which is independent from the solar inverter used by your photovoltaic panels. Thanks to this configuration, you can easily add a Powerwall to an existing solar array – even if the system has an inverter that is normally incompatible with batteries.

Operating Modes of the Tesla Powerwall

The Tesla Powerwall is a smart device with several operating modes:

Tesla Powerwall ModesDescription
Backup ReserveThe Powerwall provides backup power during grid outages. You can specify the percentage of charge that will be set aside for blackouts. If you set a reserve percentage of less than 20%, the Powerwall will display a “Low Backup Reserve” indicator.
Self-Powered ModeThe Powerwall stores excess solar energy during the day, to be used at night. If the Powerwall is fully charged and your solar panels are still producing excess energy, it will be exported to the National Grid.
Time-Based ControlThe Powerwall is programmed to charge and discharge according to time-of-use tariffs, maximising your power bill savings. For example, if you have a TOU tariff that charges 40 p/kWh during peak demand hours, the Powerwall will provide backup power during this schedule to maximise savings.
Energy Export ModeThe Powerwall sends energy to the grid at times of high demand, so you can claim power bill credits. This mode is useful if you have an SEG tariff that pays higher rates for sending electricity to the grid during peak-demand hours.
Advanced SettingsGrid Charging Mode: The Powerwall recharges from the grid when solar generation is not enough. Note that electricity providers may not allow grid charging under some conditions.
Preconditioning: Home batteries have a reduced charging efficiency when temperatures are very low, but the Powerwall heats itself up to prevent this effect.

Does the Tesla Powerwall Have a Good Warranty?

The Tesla Powerwall has a 10-year warranty that includes the following benefits:

  • The Powerwall will be free from factory defects for 10 years after the installation date.
  • The Powerwall will have 80% of its initial capacity at the end of the warranty period.

Many battery manufacturers specify a maximum number of cycles or energy throughput that is covered by the warranty. The Tesla Powerwall has no cycle limit or throughput limit when using the following modes: solar self-consumption, time-based control and backup reserve.

  • Under these operating conditions, Tesla guarantees 80% battery capacity after 10 years without an operating limit.
  • If you use other modes, the warranty is limited to a maximum throughput of 37,800 kWh. This is equivalent to 2,800 full cycles at the rated capacity of 13.5 kWh.

Getting a professional installation is very important. The Powerwall warranty only applies if the unit is installed and serviced by a Tesla-certified installer. You will lose the warranty if the battery is handled by unauthorised technicians, used outside of the rated temperature range, or installed close to a water source.

In case you sell your home, the Tesla Powerwall warranty can be transferred to the buyer. However, the new user must show proof of ownership.

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Written By

Leonardo David Photo

Leonardo David

Leonardo David is an electromechanical engineer, MBA, energy consultant and technical writer. He has also been writing articles about energy and engineering topics since 2015.

Reviewed By

Ollie Smith Photo

Ollie Smith

Ollie is the director of Ecopreneurist, with a string of successful publishing brands under his belt, he aims to make the world a better place by showcasing only the best, unbiased and reliable content on the web!

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