With all of the distractions impacting Tesla’s bottom line at the moment, it’s easy to forget that the company dabbles in so much more than rocket ships and electric vehicles.
Before Elon Musk took on his latest role as chief agitator, his vision was one of a society that was free from the shackles of fossil fuels, one that could charge a vehicle from home and reduce its reliance on the grid by harnessing the power of the sun.
You may have missed it, but Tesla’s Powerwall technology, which is essentially a giant battery pack that can store energy for use at a later time, is now in its third generation, boasting a number of improvements over previous iterations and a brace of new, automated features.
By late 2024, Tesla had deployed over 750,000 Powerwall units globally, with almost 100,000 of those part of the company’s Virtual Power Plant (VPP) program, which aims to “borrow” energy from domestic Powerwalls and feed it back into the grid when demand is at its highest.
This is particularly important in regions where the grid is unstable and homes are faced with regular blackouts. Places like Puerto Rico, where Tesla has been investing heavily in its VPP program.
Readers in the US will also likely be familiar with the sleek white packs that adorn the garage or exterior walls of a home – particularly those that are also fitted with solar panels – and supply energy to power lights, domestic appliances and the battery packs of electric vehicles.
However, the UK also has a plan to reach net zero by 2050, with renewable energy sources crucial to hitting that target. Private homeowners are becoming more receptive to installing solar, as the technology becomes more reliable and more affordable, with Tesla’s plug-and-play domestic battery set-up among the most popular.
It’s easy to see why, because Tesla aces the user experience with its electric cars and it has done so again with Powerwall, thanks to a simple and intuitive app experience that seamlessly integrates with the same software that smartphone users harness to check on their EV charge status and even unlock the car.
To prove its idiot-proof nature, Tesla invited me to drive up to the Lake District in the deepest, darkest depths of North West England (an 800-mile round-trip from my house), where it had installed one of its newest Powerwall 3 models on a remote character property nestled at the foot of the valley of Mardale in Cumbria.
A simple set-up
It took just one stop in Tesla’s previous generation Model Y to tackle the 400-odd miles required to reach the remote Haweswater Reservoir. The efficiency and ease of running and charging Tesla products never ceases to amaze me.
Upon arrival, the Model Y’s battery packs were seriously depleted, so required plugging in to Tesla’s Wall Connector for a top up.
Seeing as the residence had been fitted with Powerwall 3 and solar panels, the system was able to begin charging the car from energy stored within the Powerwall’s 13.5kWh battery pack.
A new feature in Tesla’s smartphone app, dubbed ‘Charge on Solar’, allows owners to gain greater control of the way their vehicle is charged, using excess solar energy when it is available.
Like Tesla’s Charge Limit interface, which allows owners to adjust the amount the battery that’s topped up during any given charging session, the Charge on Solar feature uses the same basic slider set-up.
In essence, owners can set their charge limit at, say 50%, which for some will be enough to tackle a week’s worth of trips, with the Charge on Solar slider set from 50% to 90%, meaning the battery gets a bonus top-up of 30% if there’s enough excess solar to do so.
With the bruised clouds hanging low over the Aquila house on the Haweswater reservoir, it didn’t feel like excess solar power was a regular occurrence. But in those places that are blessed with plenty of sunshine, it feels like a great idea.
But more than simply being a way to top up your EV’s batteries without relying on the grid, the Powerwall can also act as a back-up during black-outs and draw power from the grid during off-peak tariff times to reduce household bills.
Crunching numbers
Half expecting a gigantic, obnoxious battery pack and myriad trailing wires, I was pleasantly surprised by how compact Tesla’s system proved to be. Even when attached to the side of a quintessentially British period property, it didn’t jar with the aesthetic too much.
The Powerwall itself is a sleek white box that weighs some 130kg and measures just over a meter tall (around 43 inches) and 609mm wide (around 24 inches). This has to be paired with a Tesla Gateway – the brains of the operation – which sits inside the house and looks like an additional fuse board.
Plus, there’s another box that takes a feed from the solar panels on the roof, as well as the wiring to make it all work. It’s no wonder Tesla offers a base price, but then sends interested parties to trusted installers to get a final quote.
On that subject, the Powerwall 3 costs £6,600 (around $8,500 / AU$13,500) in the UK, without delivery or installation, plus an additional £1,170 (about $1,500 / AU$2,400) for the required Gateway. Tesla points out that there may be “other costs” and fees from the certified installer.
Most ballpark estimates put a standard installation at over £10,000 (around $13,000 / AU$20,500), which is a hefty initial outlay. But Tesla predicts that, on average, Powerwall users can save around £1,450 (around $1,800 / AU$3,000) per year on their energy bills when paired with solar that, by the way, will cost even smaller residences at least a further £6,000 (about $7,700 / AU$12,300) to install.
So with some quick napkin calculations, it will take an average of 11 years before your Tesla Powerwall 3 breaks even – although Tesla’s predicted savings seem exaggerated, given that Uswitch calculated that the average UK household’s electricity usage equates to around £800 per year.
But it’s not just about the financial argument, as the reduction on the grid is a big talking point, especially as more households start charging EVs from home.
“The average EV will roughly double the annual electricity use of a typical household and in future, as EVs grow in popularity, the flexibility of your home charging and that energy delivery will become understandably more important,” a spokesperson from home charging experts Ohme told me.
“For EV drivers that means charging their cars at the cheapest and greenest times, while for energy suppliers that means maximizing use of renewable energy and helping them to better predict and control that supply and demand domestically, locally and nationally to ensure there’s a healthier energy system overall,” they added.
By supping energy when it is least in demand (usually in the dead of night) and discharging from Powerwall when the nation is cooking dinner and bingeing Netflix, it prevents the big spikes in that cause energy providers headaches.
Ohme does this with its next-generation home chargers, which can dynamically charge all of the EVs on its network, according to differing levels of supply and demand on the grid. But Tesla’s Powerwall effectively achieves the same results, with the added bonus of also using solar power.
Riders of the Storm
While there are other solar and battery storage systems on the market, Tesla excels with its software, enabling even knuckleheads like myself to easily see how the product is performing.
Alongside the aforementioned ‘Charge on Solar’ feature, Tesla also offers ‘Storm Watch’, which tracks incoming severe weather and automatically charges Powerwall to its full capacity to prepare for any potential outages.
This will then allow for a seamless switch from the grid to Tesla’s domestic battery system, allowing most households to go about their business for a day or so before the Uninterrupted Power Supply (or UPS, as it is known) needs topping up again.
The smartphone app also gives a clear breakdown of how the Powerwall is performing, how much electricity the household has used in a day, week, month or year, as well a simple graphical breakdown that visualizes the percentage that’s been derived from solar or from the grid.
In sunnier climates, the app might show an ‘Impact’ figure that reveals the residence has been 88% ‘self-powered’ in any given 24 hour period.
In the last quarter of 2024, the Powerwall set-up in the admittedly gloomy Lake District house provided energy for lighting and appliances 4% of the time, according to the app I was given access to, with another 4% provided by solar. The remaining 92% was taken from the grid. It provided £73 in estimated energy value.
The first three months of 2025 proved much better, with 4% solar, 10% Powerwall and 86% from the grid, providing £134 of estimated energy value.
But what wasn’t so obvious was the amount of money it was saving the household by charging during off-peak times, when energy tariffs are considerably cheaper, and discharging during the most expensive period.
One section in the app revealed that the Powerwall had discharged almost as much as it had charged in the first three months of this year, suggesting the household was essentially benefiting from the cheaper energy tariffs 24/7.
For those thinking of ‘going solar’, Tesla’s ecosystem is as simple as they come… arguably stylish for a domestic battery system, too. Plus, it works seamlessly with the existing app that its EV owners will already be so familiar with.
But until the price of this technology comes down, it feels like it we are back in the early days of electric vehicles again. A technology that’s reserved for the wealthy early adopters that are willing to swallow the significant upfront costs.
