Energy
A Tesla Powerwall-powered Home: Will it Pay Off?
We’ve all heard by now that the Tesla Powerwall home battery is designed to store electricity, generated from solar panels and electricity captured from utility companies during off-peak rates, and provide overall independence from the grid.
It sounds like an amazing product, and I’m sure it is, but will it pay off to own one?
Understanding the Powerwall
The Powerwall is an energy storage unit otherwise known as a battery. It comes in two sizes today (although they can be stacked/expanded), 7kWh and 10kWh (what’s a kWh?) and costs $3,000 and $3,500, respectively. Note that the cost excludes an inverter and installation, both of which can be quite expensive to the point it can double the total out-of-pocket cost. The specs for the Powerwall come in at a whopping 220 lbs / 100 kg (unclear as to which capacity this represents) and 52.1″ x 33.9″ x 7.1″ or roughly 3.5 x 3 feet in dimension.
The concept is simple, the Powerwall battery stores energy generated through your utility company when rates are the lowest (or through solar panels) and ready on tap when you need it.
Installation
Tesla notes that the cost of the Powerwall does not include the inverter or installation. An inverter alone such as the one SolarCity uses can cost around $2,000 which does not include a separate installation cost.
Installation will vary depending on the following:
- Does your residence have an existing net metering?
- Is it already wired for a generator?
- What is the distance between the photovoltaic solar panel hardware and the location to where Tesla’s Powerwall would be mounted? The shorter the distance, the less cabling to run and thus a lower installation cost.
At 200+ pounds in weight, you’ll need to ensure that there’s ample space and structural support to where the Powerwall will be installed. There also needs to be sufficient cooling space and ventilation in the mounting location.
Primary Use Cases for the Tesla Powerwall
Tesla proposes two primary use cases for the Powerwall:
- Time of Use (TOU) offset
- Backup power
Let’s explore each of these options.
Powerwall provides a Time of Use offset
In many states and countries from around the world, a Time of Use (TOU) electricity rate is available through the local utility company. The concept is simple: you pay different rates at different times of the day. During peak hours the rates are higher than they are during off hours. Many Tesla owners that live in these areas that have TOU pricing will charge their cars during the evenings when rates are typically the lowest.
Unfortunately TOU pricing is not widespread here in Massachusetts but if you’re able to take advantage of it in your area, then the Powerwall may bring some value although it would take quite awhile to recoup the initial investment.
Taking a look at TOU rates from Southern California Edison, we can see that their off-peak rate is $0.11 while peak rate comes in at $0.46 for a difference of $0.35 per kWh. The large Powerwall unit is capable of storing 10kWh. Assuming you are able to fully charge the battery during off-peak hours each and every day, you would save approximately $3.50 per day.
Since the unit itself (without install) costs $3,500, it would take approximately 1000 days or just shy of 3 years before you “broke even”. This is assuming the utility company continues to offer off-peak rates throughout the year. Add in the installation costs and you’re looking at closer to 5 years before breaking even on the Tesla Powerwall investment
Of course, there’s the argument that having a solar panel system would allow you to charge the Powerwall battery for free through sunlight, but only if you fully ignore the cost of the solar system itself.
RELATED >>> My journey to installing a SolarCity system
Owning or leasing a solar system comes with its own break-even calculations so you’ll have to factor that into the equation with the Powerwall.
Powerwall provides backup power
The other stated potential use case for the Powerwall is to use it for backup power in the event your home power is completely cut off from the grid.
Don’t expect to power your entire house with just a single 10kWh Powerwall. Tesla’s site provides some good examples of how much power common home appliances draw. For instance the Powerwall would be able to power a typical refrigerator for 2 days. This time would of course be extended if you were able to replenish the battery through a solar system.
In the case of an extended power outage (think Zombie apocalypse), you may be able to power essential home services indefinitely with a properly sized battery and solar system.
The ability to re-fill from solar is a nice benefit, but the alternative would be a noisy gasoline powered generator.
A 6.5kW generator can be had for for as little as $800. That generator can output 32,500kWh (50% load x 10 hours according that link). That’s 3x the power at less than 25% of the cost of Tesla’s offering. The cost for that power? About $15. The generator, unlike the Powerall, is mobile and can go anywhere you go. Generators typically have very low maintenance and can be re-filled quickly regardless of weather conditions (hurricanes, snow storms, etc – all likely conditions that will cause loss of power).
I have a Honda 6.5kW generator. My house has its own well, septic etc. When power goes out I fire up the generator and power the things I need. I have water, hot showers, heat (oil, fired by electric which is powered by the generator), lights etc. I have run for days off that generator in some of the worst weather conditions New England can throw at me. I’d argue if you’re serious about backup power, then a generator is still the best option.
Powerwall, as a backup power option and also from a pure cost-perspective, I feel is only a good fit for those who have a solar system installed and live in an area where the climate is more stable.
Energy
Taiwan power firm bets big on Tesla Megapacks as AI data center thirst grows
Taiwan’s Apollo Power orders 260 Tesla Megapacks, betting AI data centers will need more electricity.
A Taiwanese power company has ordered 260 Tesla Megapack 2XL units, roughly 1GWh of storage, betting that electricity rather than chips will decide how fast AI data centers come online. Apollo Power signed the contract with Tesla’s Taiwan energy arm on October 8, according to the company’s filing with the Taiwan stock exchange.
The filing says the units are meant for behind the meter storage and resilient grid projects, with delivery in batches from the end of 2027 and sites operating in 2028. Apollo and Tesla did not disclose a price, citing a confidentiality agreement. Apollo plans to pay for the equipment through a cash capital increase and bank financing, and it noted the purchase is not revenue and does not mean it holds firm orders from its partners.
Biggo reported that only about 33 units are under signed customer contracts, with roughly 150 more in negotiation. The same report put total project investment near NT$130 billion, but that figure includes installation work, with the equipment itself making up about 40 to 50 percent. In other words, a large share of this order is Apollo reserving supply ahead of demand. Apollo’s chairman told local media global large storage supply is tight, which is why the company locked in the units early, according to Yahoo Taiwan Finance.
Apollo also launched an AI data center and grid resilience alliance with Phison, Gigabyte and Shihlin Electric. The pitch rests on a pilot at Phison’s Zhunan plant, where Apollo and Tesla Energy Taiwan installed grid forming Megapack 2XLs in June. Tesla Energy Taiwan general manager Sun Hsiao-Han said the project went from demo to 1GWh in four months, and that Tesla Energy has deployed more than 50GWh worldwide.
Taiwan’s cabinet has approved amendments that would require large energy users to install their own generation and storage, which gives enterprise storage a regulatory tailwind.
The deal fits a pattern Teslarati has tracked. Tesla’s Megablock targets 1GWh commissioned in 20 business days, a pitch aimed squarely at fast moving data center builds. Megapacks already back xAI’s Colossus in Memphis and a 400MW AI campus in Brazil. Sun Media adds that Megapack 2XL was named among the first products in Nvidia’s DSX Ready qualification for battery storage in AI factories.
Deliveries are more than a year away, so the real test is how much of that 260 unit order turns into signed customer contracts.
Energy
Tesla Model 3 and Model Y can now do what only Cybertruck could
Tesla Model 3 and Model Y can power your home with Powerwall 3 during outages.
Tesla has turned its two top sellers into backup batteries for the house.
Tesla Energy announced on Tuesday that Powershare Home Backup is now available for new Model 3 and Model Y vehicles paired with a Powerwall 3, saying the car can “extend your home backup by over 2 days.” Minutes later, Tesla’s main account quoted the post with a broader pitch: “With Powerwall 3, every Tesla can now serve as your home’s backup battery.”
Until this week, the Cybertruck was the only Tesla that could send power back into a home, and that capability only began working alongside Powerwall 3 last month, after years of ambitious targets.
Tesla’s updated Powershare page says every Model 3 and Model Y ordered in the U.S. or Puerto Rico on or after October 1, 2026 can use the feature. Some, but not all, earlier cars also qualify. Owners can check on the touchscreen under Software, then Additional Vehicle Information, where a capable car shows “Powershare Support: Enabled.” As Electrek reported, bidirectional power on the two cars runs through an inverter Tesla calls PCS2 Lite, and the company has not said when that part entered production on each trim.
The home side is simpler. A house that already has a Powerwall 3 and either a Wall Connector 3 or Universal Wall Connector needs no additional equipment, and Tesla says compatibility is enabled through a software update. When the grid drops, the Powerwall and the car work together, with up to 11.52 kW of continuous power available. Tesla’s “over two days” estimate assumes a home using 30 kWh per day and a car starting at a 90 percent charge. Standard trims are rated for up to two days, while the Cybertruck adds more than three.
There are limits. Powerwall 2 and Powerwall+ support is listed as “coming soon.” Model S and Model X are not included, and Grid Support, the program that lets Cybertruck owners in Texas send power back to the grid during demand spikes for bill credits, is not available for Model 3 or Model Y.
The rollout also lines up with something Elon Musk said more than three years ago. At Tesla’s March 2023 Investor Day, Musk said, “I don’t think very many people are going to want to use bidirectional charging, unless you have a Powerwall.” Tesla has now shipped the feature for its volume cars with exactly that requirement attached.
The Powerwall pairing was the hard part on Cybertruck. Tesla told owners in December 2025 that Powershare with Powerwall had been pushed to mid 2026, and lead engineer Wes Morrill explained that two devices capable of forming a home’s grid have to negotiate which one leads during an outage, across multiple generations of hardware. With that work done for the truck, Tesla was able to extend it to the Model 3 and Model Y within a month.
Ford and GM have offered home backup from their EVs for several years, but both require a separate inverter and backup hardware. Tesla’s version leans on equipment many Powerwall 3 owners already have on the wall. Powershare for the two cars also ships as part of software update 2026.38.3, the same release that began delivering Halloween Mode on Tuesday.
Elon Musk
Google just picked SpaceX for its first step into orbital AI
Google will launch its first Project Suncatcher AI satellite on SpaceX’s Transporter-18 rideshare next week.
Google is about to put its own AI chips into orbit for the first time, and it is paying SpaceX to get them there.
The company said Thursday that the first in-orbit test of Project Suncatcher, its research effort to find out whether space can host large-scale AI computing, will fly next week on SpaceX’s Transporter-18 rideshare mission.
The satellite, called MVP, is about the size of a refrigerator and carries four of Google’s Tensor Processing Units, the same chips Google runs in its ground data centers. Google originally planned to launch two custom satellites in 2027, but chose to move faster by integrating its chips into a satellite.
MVP’s solar panels supply about one kilowatt of power, and Google will run Gemini models on the TPUs only in bursts of roughly 15 minutes before the chips shut down so the radiators can shed heat. In a blog post, Google said its Trillium TPUs survived vibration testing that mimicked sustained launch loads of up to 10g, with individual components seeing 50 to 100g, and handled a radiation dose greater than a five year mission would deliver.
SpaceX and Google mull massive partnership on Musk’s orbital data dream: report
Next week’s flight, slated for October 1, follows a relationship that became public in May, when Teslarati reported that Google was in talks with SpaceX for a launch deal tied to orbital data centers. Google also holds a stake of roughly 6% in SpaceX.
The two companies are chasing the same idea from very different starting points. SpaceX’s own orbital compute program is built around the AI1 satellite, a roughly 70 meter structure derived from Starlink V3 hardware that is designed for 150 kW of peak compute, about 150 times the power MVP will draw. Elon Musk has brushed off concerns about crowding orbit with those satellites, and SpaceX is building its Gigasat factory in Bastrop, Texas, to produce them, targeting an annualized rate of about 1 GW of space compute by the end of 2027.
Musk also posted on X on Thursday that “the amount of compute in space will obviously round up to 100% of all compute.”
Google has been more cautious in public. Its research estimates that launch prices need to fall below about $200 per kilogram before an orbital data center can compete with a ground facility on energy cost, a threshold the company believes could be reached around the mid 2030s. The Suncatcher team has said it expects the effort to remain a project rather than a product for years, which leaves the first real test of its hardware riding on a rocket from the company with the most aggressive timeline in the field.
