The Tesla Powerwall is a rechargeable lithium-ion battery that can be installed in your home to store harvested solar energy or energy from the national grid.
It is possible to install a maximum of 10 Powerwall units as part of a complete system in your home to maximize the amount of energy you can store and reduce your reliance on the national grid.
While Tesla is the market leader in solar batteries because of its high energy capacity, high quality, and beautifully designed products, it is one of the more expensive options available.
So is the Powerwall worth it? And how do other alternatives on the market compare?
Let’s find out…
Do I need a solar battery if I have solar panels?
It’s not a necessity to have a battery if you have solar panels, however, installing a solar battery like the Tesla Powerwall means you can store electricity for when the sun is not shining, like in the evenings.
This allows the use of the solar energy you generated during daylight hours overnight dramatically reducing the amount of electricity you may need to draw from your supplier.
It is also possible to charge the Tesla Powerwall from other sources, for example charging it overnight when electricity from the grid is cheaper e.g. during off-peak hours (depending on your tariff).
What models of the Tesla Powerwall are on the market
The Tesla Powerwall first hit the market in 2015, closely followed by the Powerwall 2 in 2016, which was then updated in November 2020.
The latest version the Powerwall+ followed in April of 2021 which is a combination of the Powerwall 2, a Backup Gateway, and a solar inverter.
The Backup Gateway is a system that works with the Powerwall to prevent your home from being affected by power cuts.
It will detect power outages and automatically power your home with the Powerwall battery.
Related solar guides:
- How many solar panels do you need?
- Smart Export Guarantee
- Can you install solar panels in a conservation area?
- Best 4kw solar system with battery storage
- Sunshine hours map UK
- Best Solar Panels
- Solar panel output calculator
What does the Telsa Powerwall cost?
The Tesla Powerwall battery on its own costs around £6,600 with an upfront deposit needed of £400. However, the true cost of the Powerwall is much higher.
You will also need the supporting hardware which costs £1,700.
Then add on the cost of the installation which can cost anywhere between £800-£2,800 taking the cost to between £9,100- £11,100.
It is recommended you use an accredited Tesla installer and you will need permission from the National Grid before installation.
You may need some electrical work in your home to support where the Powerwall will be installed. Be prepared that this may add extra costs to the final bill.
Tesla Powerwall’s capacity
The latest version of the Tesla Powerwall 2 has a capacity of 14kWh.
You have the option of 5.8kW’s of continuous power or short 10-second bursts of 10kW.
This large capacity makes it perfect for larger households, households that want to live off the grid, or households with electric cars that wish to use solar energy to charge them.
Tesla Powerwall’s dimensions
The Tesla Powerwall’s dimensions are 1,150 x 753 x 147 mm.
It can be floor or wall-mounted and can be placed both inside or outside.
It is also possible to stack up to 10 Powerwalls together.
Tesla Powerwall’s warranty
Tesla offers a 10-year warranty on the Powerwall.
This includes an unlimited amount of cycles and a guarantee it will still work at a minimum of 80% capacity.
This means if your Powerwall drops below 80% of its original capacity in 10 years you will qualify for a replacement.
The expected lifespan of the Telsa Powerwall is 20 years.
Alternatives to the Telsa Powerwall
Enphase Encharge
3.4-10.5 kW capacity 3.84 kW continuous power. £4,000- £8,000+
Pros to the Enphase battery include, different sizes being available, which the Tesla does not offer, and can detect power outages.
However, its price is very similar to the Powerwall despite having a smaller capacity.
Generac PWRcell
9-18 kW Capacity 3.4-6.7 kW continuous power £7,400+
Pros include one of the highest capacities on the market, as well as a range in sizes.
The downsides are the price is still high and its warranty is based on the amount of energy storage and not the number of years.
LG CHEM RESU 10H
9.3 kW capacity 5 kW continuous power £5,800
Claims to have a lifespan of 4,000 cycles and has battery cells layered in a unique pattern which they claim prevents failures and provides long-term reliability.
BYD Battery-Box HV
5.1-12.8 kW capacity 5.1-12.8 kW continuous power £3,300+
This battery boosts a high capacity and high continuous power for a much lower price tag. It comes in multiple sizes.
The only downside is a lower warranty.
Powervault 3
8.2 kW capacity 4.0 kW continuous power £4,100+
Voted Best for off-the-grid living by the Eco Experts, this battery is much more affordable with a high capacity.
Benefits to the Telsa Powerwall
As well as storing the power generated from your own solar panels there are a number of other benefits to choosing the Powerwall in particular which include:
Liquid Thermal Control System
This controls the Powerwall’s internal temperature for top performance through all seasons and all climates.
Power the Battery with Multiple Sources
You can charge the battery from other sources if need be.
This can be done during the night when electricity is cheaper.
This electricity can power your home when your solar panels are producing less energy, like on a cloudy winter’s day.
Meaning you may never have to pay the full price of energy again.
Provides Back-Up Energy
The addition of the Back-up Gateway means it can detect power outages, automatically becoming your home’s energy source.
You’ll never have to deal with power cuts again.
Other advantages of the Tesla Powerwall
- You can sell energy back to your supplier, getting a return on your investment.
- The system is completely automated. You’ll never need to carry out maintenance.
- It can be installed inside or outside.
- It’s an attractive addition to your home with its sleek black design.
- It’s safe to have around children and pets with no visible wires or areas that will overheat.
- Choose from a wall or floor-mounted installation to make it fit perfectly in your home.
- Ability to stack up to 10 batteries together.
- Built-in DC-AC inverter to work with your solar panels.
- The Tesla App connects to its smart inverter – which monitors your home’s energy use and sends alerts for weather forecasts and energy usage estimations.
- It will increase the value of your property.
Is the Powerwall right for your home?
For most households, a battery with 5-10 kWh is large enough to power their home in the evenings and overnight.
With a capacity of 14kWh, it is likely a smaller less expensive battery will be enough for your home.
The Powerwall, as stated above, is worth it if your energy use is higher than normal.
This could be because you charge an electric car, or you want to live as off the grid as possible.
For anyone with solar panels and potentially anyone on a certain tariffs that want to store cheaper off-peak energy the Powerwall will save you money.
Help with the cost of the Tesla Powerwall
Installing a battery like the Powerwall on top of the cost of installing solar panels is expensive.
However, there are ways to help with the cost, including the following:
The Smart Export Guarantee (SEG)
A system that can earn you money by exporting your stored energy back onto the grid.
You’ll need to check if your energy supply does this, if so 4-6/kWh is a good rate.
0% VAT on your solar panels and Powerwall
You will only qualify for this if you install both at the same time with the same company but it could really save you pennies if you plan on doing this.·
If you’re in Scotland you could benefit from solar energy grants.
The Home Energy Scotland Loan means you can get up to £6000 and £5000 interest-free when you install panels and batteries.