(1) We simply don't know what the useful life is going to be because of how new the advancements of AI focused GPUs used for training and inference.
(2) Warranties and service. Most enterprise hardware has service contracts tied to purchases. I haven't seen anything publicly disclosed about what these contracts look like, but the speculation is that they are much more aggressive (3 years or less) than typical enterprise hardware contracts (Dell, HP, etc.). If it gets past those contracts the extended support contracts can typically get really pricey.
(3) Power efficiency. If new GPUs are more power efficient this could be huge savings on energy that could necessitate upgrades.
Nvidia is moving to a 1 year release life cycle for data center, and in Jensen's words once a new gen is released you lose money for being on the older hardware. It makes no longer financially sense to run it.
Companies can’t buy new Nvidia GPUs because their older Nvidia GPUs are obsolete. However, the old GPUs are only obsolete if companies buy the new Nvidia GPUs.
based on my napkin math, an H200 needs to run for 4 years straight at maximum power (10.2 kW) to consume its own price of $35k worth of energy (based on 10 cents per kWh)
The deciding factor on whether to believe someone should not be whether they believe themselves, but whether they are worth believing. A murderer who acts in good faith is still a murderer.
Finally, developers are realizing that it's not how you write code or who writes the code, it's figuring out WHAT to write. LLMs are finally exposing this because the feedback cycle is so short.
> Finally, craftsmen are realizing that it's not how you woodwork or who makes the furniture, it's figuring out WHAT to make. IKEA is finally exposing this because the feedback cycle is so short.
You are assuming that the only downside of building a broken product are the development resources you spent in the process. That might be true for a new product, and only if it doesn't cause damage to your customers. For an established product that needs updates, breaking it means losing a lot of the value that was in that product.
At which point if you're short on capacity (but who knows how your demand might shift over a decade) it's not like you need to replace the original batteries to get that 20% back, you will probably be able to just expand the pack to bring the capacity up.
EDIT: As others have pointed out, powerwalls have inverters built in so it's not totally apples to apples. You can get a beefy inverter for $5k and it's still cheaper and you wouldn't need an additional inverter every time you add a battery.
There's going to be a bloodbath in that market in the next years. There are a lot of battery producers and most of them are not producing at full capacity. At the same time, manufacturing cost is dropping as well.
Some battery makers are producing batteries at a cost level of around 60$ per kwh. At that cost, the 16kwh battery would come out below 1000$ (not the same obviously as the product price). Sodium ion might push those prices even lower. Below 50$ soonish and eventually closer to the 10-20$ range in maybe 5-10 years. At that point we're talking a few hundred dollars for a decent size domestic battery. You still need packaging, inverters, etc. of course.
But the ROI at anything close to those price levels is going to be pretty rapid. And it wouldn't break the bank for households across the world. Add a few kw of solar on roofs, balconies, etc. It won't solve everyone's problems and certainly not in every season. But it can help reduce energy bills in a meaningful enough way. Even in winter.
Also worth pointing out: most of the US is south of Cornwall. The Canadian border runs roughly at 49 degrees latitude. Cornwall is the most southern point in the UK sits at 50 degrees. If it can work there, most of the US has no excuse. Also, the UK isn't exactly well known for their clear blue skies. Even people in Scotland much further north manage to get positive ROIs out of their solar setups.
I installed a 16.5kWp ground-mount array a month ago. I live in the US Northeast, in a mountainous location that means we get late sunrises and early sunsets. Nevertheless, based on my one month of data, it looks like we can generate all the power we need for our household on a sunny winter day, excluding electric vehicles. Even on overcast days, we can sometimes offset a significant portion of our usage. My locale does not have time-of-use rates, so there’s no point trying to do arbitrage for electricity prices. So right now I just have our battery configured for backup. My hope is that during the summer months I can reconfigure the system to use the battery to reduce grid reliance instead.
The expiring tax credits were what forced my hand. I’m the kind of person who likes to install things himself, and I probably would have gone that route for solar too, because the materials costs (sans battery) aren’t even half of the total cost.
Here in Europe, we got more than a month's worth of foggy, cloudy weather (something that looks like will keep being a thing), which is something I became painfully aware of as an owner of a solar setup.
No amount of battery banks can tide over such a long stretch.
By the way, let me ask you - considering your location, you must be getting a lot of snow, how do you deal with it, is it a problem? Panels are quite hard to reach on the roof.
I do indeed get a lot of snow. In January and February it snows roughly once every two days, although usually in small amounts.
Fortunately I have a ground mount. The bottom row is roughly at waist height. I can (and have been) sweeping the panels off with a large push broom. Because my array is so large, I can only reach the bottom half of the array. But this usually is enough. When the panel starts to generate power, it also tends to heat up; the snow on the top half then often slides off on its own.
I might invest in a longer broom. It is not uncommon for people here to own “snow rakes” to remove large snow loads from their roofs. These usually have a rubberized “rake” with a very long aluminum handle. Or the novelty of this might wear off and I’ll just let the panel do its own thing. It is pitched rather steeply (close to 45°) and based on my observations of my neighbors, panels tend to shed the snow on their own eventually.
I've got a similarly sized ground-mount array, and I push the snow off with a triple-telescoping aluminum pole with a large squeegee on the end. An actual snow rake might be better, like the one you describe, but my setup gets it done. It takes some effort, but it's worth it to be able to collect the solar energy that would otherwise just reflect off the snow for days.
One thing to remember is as it becomes more widespread line costs will go up (assuming they are subsidized by kwh use, which they generally are) and no-sun power prices will increase as it's the only time when the grid needs power from non solar producers and they still need to cover cost incurred while they're not producing.
That will push the economics towards completely off grid systems as more people adopt solar, so if people are planning it for themselves they should probably consider that it will make sense to expand their set up in the future and that there might be a price crunch due to higher demand because of larger systems coupled with more people wanting to switch.
My partner works in the field and we once talked about this. I think the idea is that individual consumers’ and businesses’ batteries can serve the grid as needed. For example, if your car is fully charged and you don’t need it today, it can top up local needs.
So I think the writing isn’t on the wall yet for line price going up, although I’m of course talking of a) Belgium, and b) a future that could go wrong if utilities don’t fund smart metering.
That’s how it works for us here in Australia. We have 16Wh of solar and 40KWh of battery, and pay (and receive) wholesale rates for electricity. During the say electricity prices are very low or negative, and we run off the solar and charge the car then. In the evenings when demand is high electricity prices can spike, and our system will automatically sell to the grid then. Sometimes we may need to draw from the grid in the early morning to make up for that, but the price we pay then is insignificant compared to what we make selling the day before.
An interesting possible is the grid becoming smaller. Neighborhood scale.
In many places from Central Europe and further north dealing with arctic cold spells and dunkelflautes are near impossible for a home solar and storage setup.
But you also don’t want to pay for a continental scale grid the remaining 51 weeks.
So in your neighborhood add some wind power and a good old trusty diesel/gas turbine running on carbon neutral fuel and keep the costs to a minimum.
This is addressed by crowdsourcing generation and storage to household batteries. Surplus energy is banked locally instead of being dumped on the grid. The utilities buy it back from homeowners at wholesale rate under demand response programs when they can't meet demand.
Many cities in north america you cant get occupancy without grid tied electricity, so every house incurs the coat of bas government policies on transmission. Its why i havent bothered with this yet. The optimal setup for here is natural gas generator, some battery and some solar given how stupid the fixed charges are here but you cant live in your house if you disconnect from the grid (even better would be for fuel cell manufacturers to offer something sized for a house so i can get hot water put of it as well and a silent unit)
I'm not so sure. There are a lot of large-scale applications that would gobble up battery supply if it hit a certain price point. Grid-scale storage and datacenters, for example.
If prices for residential gear falls too much, I expect the manufacturers would just stop making it and focus on the commercial options instead.
IMO, there's close to no bad usecase for batteries. In almost all their applications, they end up spreading out power consumption favoring cheap energy for expensive energy.
If a datacenter installs a solar array + a giant battery pack for their power, that's much better than them heavily relying on a natural gas plant to generate power when the lights are out.
The commercial options would fall further in price probably than consumer prices. If you buy in bulk, you do research to find the most cost effective options. That's a common pattern with many things. I don't see why batteries would be any different. If anything, I'd expect consumer batteries to have higher margins. Tesla batteries are a good example probably. At those prices, a Tesla car would be unobtanium. Obviously they charge a lot less for batteries that go in a car.
The reality is that many battery factories might be operating at 40-50% capacity only. Exact figures are hard to come by but there are lots of warnings about over production, surpluses, etc.. That spells a lot of trouble for some of the newer battery producers promising more efficient batteries. Because unless they price match, they price themselves out of the market almost immediately.
Just 11 companies control 90+% of manufacturing capacity, I think they might need to adjust their ambitions in the face of demand, but I think most of them are too big to fail.
Its weird to read about Schneider Electric not bothering with brand awareness. They aren't a household brand, sure, but they are well up there with Siemens and the like in industrial/b2b sector and their marketing budget is allocated accordingly.
IIRC, the original idea was that they would pull older batteries from circulation when their capacities dipped, and then repurpose them as powerwalls, an application where weight is irrelevant.
This was back when they expected the batteries to plateau at ~80% capacity after a few years, and they had battery swapping on the roadmap, so they needed to plan for a future where they had a steady supply of batteries that car customers did not want.
The idea took hold, but the batteries lasted longer and swapping didn't pan out, so now they are competing with themselves for battery supply.
Electric car battery degradation has been super interesting, in that they are going way further than people thought they might. Jonny Smith on youtube bought a 300k+ mile Tesla and the battery is at like 75% health.
As far as I can tell if your battery isn't air cooled, it can go a very long way
There was some research[1] that strongly suggested that varied use makes them last much longer than the steady use that most battery tests do. That is, bursts of high-current draw followed by moderate draw etc vs the constant current load typically used when evaluating battery performance. From the paper:
Specifically, for the same average current and voltage window, varying the dynamic discharge profile led to an increase of up to 38% in equivalent full cycles at end of life.
This was unexpected, hence explains why they fared better than predicted.
Huh, unexpected is right. Bursts of heavy usage being better for longevity than steady usage goes against pretty much all conventional engineering wisdom.
Without knowing anything about it, I would posit that degradation accelerates the longer the battery is kept above some threshold temperature.
So, a heavy-burst+low results in a sudden high temperature then settling into a lower temperature. Steady flow keeps it at moderate temperature (above threshold) for a long time.
The paper notes there are multiple degradation mechanisms at play, and they are influenced by different factors, such as age, cycles, depth of discharge, state of charge at rest and so on. Hence the non-trivial response to more realistic discharge curves.
However they also note more material studies are needed to understand these mechanisms better.
What do you mean? It did pan out for Tesla. Faking a single demo granted them 75% more ZEV emissions credit government subsidys [1]. That increased their profits by hundreds of millions of dollars.
All they had to do was go on stage and “swap” a battery without any clear video of the process and never “demonstrate” it ever again.
This is a company known for faking prominent demos like the FSD demo (where it crashed into a wall during filming), the solar roof demo (where they used regular roof tiles and claimed they were solar panels), the optimus demo (where they were teleoperated), etc.
Assuming they even did a battery swap, for which the official demo presents no clear video evidence, preferring overhead views over a close-up of the process or a glass enclosure to see the inner workings, it was at best a one-off custom-made device at the time. The one battery-swap station they claim existed has zero stories of any actual battery swaps, instead only evidence of it operating as a regular Supercharger [2].
They didn’t fake the demo, but the legislature quickly rewrote the law because it was intended to give Toyota ZEV credits for hydrogen cars.
Tesla did briefly operate a swap station at the site of the Harris Ranch Supercharger until California changed the rules.
There are several reports from people who used it on teslamotorsclub.com, and I saw it with my own eyes.
Hilarious that your source is Ed Neidermeyer. Perhaps the only thing more impressive than Elon’s lies about the state of self driving are Ed’s lies about how Tesla is going bankrupt Any Day Now.
It’s ok though, Ed’s stock manipulation antics enabled me to stuff my IRA with Tesla shares (since sold, when Elon went nuts) and make a nice little headway on my retirement savings.
Cool. Then if you are not lying, then it should be easy to present a clear video demonstrating the automatic battery swapping machine in action and swapping out a battery in 90 seconds as claimed in the demo.
Battery swap was and remains really risky for anyone doing it. You're taking a $10k asset, and swapping it for another $10k asset of unknown provenance. Does anyone really want to be in a situation where they purchase a new Tesla with a brand new, max-range battery pack, then swap it once on a road trip and get one that's been used for 300k miles and is at 75% of original capacity?
The bigger risk is you need a standard battery pack. Sure you can put 3 in a truck or something, but you lose all the space that a standard battery size wouldn't fit but you can cram a cell in. Electric car design is about stuffing batteries where there is space - you need a lot of cells, but the individual cells are small.
As long as you can always swap your battery again I don't see the problem
As long as the average battery health in the system is like 90% and the minimum is say 80% why would you care if you're getting a new battery every few days?
If anything it removes a big cause of depreciation from your car
That is fine if you always are swapping. However if you normally charge at home that becomes a big deal - if your current battery wears out/fails because it has 500,000k miles on it are you out a new one? Do you pay for the tow to get to a swap station? Again, if everyone always swapped this would be easy to amortize and not a problem but the mixed use.
Of course this isn't a new problem. I know people who own their own welding gas tank - but they always swap the tank out. The place they swap at somehow handles when the tank needs to be re-certified - and people don't ask questions.
In some mysterious future where swapping EV batteries during a road trip is a normal activity, then the battery packs won't be living in a vacuum -- their status can be known. Whether it is known by reading the pack's own electronics, by status reports from connected vehicles and charging stations, by direct measurement, or by some combination of these things: The status is knowable. It doesn't have to be a big ball of mystery.
How much value the marketplace finds in this health status is a different question. And this question is one that we cannot yet know the answer to -- this is not a reality that we presently live in.
We can speculate about how that potential future may be shaped, but that kind of speculation is kind of meritless since that version of the future may never actually happen (and at the present, it sure does seem very unlikely to happen any time soon).
1. California changed the rules shortly after Tesla demonstrated their swap station, which practically eliminated the tax credit for battery swap (at the behest of lobbyists for Toyota, who were backing Hydrogen Fuel Cell technology). Specifically, the credit would be prorated by the percent of “fast refueling” sessions a car did, so EVs primarily charged at home received almost nothing while HFCV got the full credit. Building swap capability adds complexity to the car (think about all the fluid connections), which isn’t worth it without credits.
2. It was also around this time that a Model S ran over an anvil (or something) which punctured the pack and started a fire. In response, Tesla added an aluminum battery shield, which further complexifies swapping and was probably the final nail in the coffin.
3. The logistics of storing your very expensive battery (so you could get it back later) basically make the system unworkable. When the Tesla swap station at Harris Ranch (you can still see the former building, next to Harris BBQ, which currently houses the restrooms) was operational, you had to make a reservation some hours in advance so that Tesla could have a pack ready and be ready to take your pack to/from storage.
3a. Gresham’s Law. Without eventually returning the pack to the original owner, there is an adverse selection problem: people with very weak packs will gladly roll the dice on a swap, but those with brand new packs are reluctant. So the average quality of packs in the swap network will quickly decline creating a death spiral.
3b. You could probably fix 3a by leasing the battery (or selling battery-as-a-service) but car buyers mostly don’t like that, especially back in 2013.
In addition to all of that, it just doesn't outcompete recharging in the end.
Even if the swap station got to where it was hoped (no reservation needed, automated, drive in, swap, drive out), you'd have a choice between a ~5 minute stop at a swap station, or a ~10-20 minute stop at a charging station. The swap station is always going to be more expensive since it's inherently more complicated, so you're spending more to save a few minutes. And when you stop at the swap station you can go answer the call of nature and grab a snack while you wait. If you want to do either of those anyway, then visiting the swap station means you'll do the swap, then go do those other things, and probably not save any time at all.
Charging time just isn't that much of an issue at this point. I've been driving a Tesla for a decade at this point, with thousands of miles of road trips around the eastern US, and I've never found myself wishing for battery swap infrastructure. Newer cars charge much faster than mine does, too.
I could potentially see value in a car with a smaller built-in battery for use around town, and an empty space for a larger battery, that you rent from swap stations for longer road trips. Of course, that doesn't work with anything on the road today.
Probably because the economics just don't make sense here. You'd have to have so many compatible cars on the road, driving all day with no opportunity to charge. I'm having a hard time imagining a place I've been to in North America where that'd seem logical.
> As of June 2024, Nio had installed 2,432 power swap stations in China, including 804 along highways, representing the largest battery swapping network in the country. Nio aims to expand to 4,000 stations globally by 2025. By February 2025, Nio had 3,106 battery swap stations in China, with 964 located along highways. In January 2025 alone, Nio added 111 swap stations and provided 2,949,969 battery swap services, averaging 95,160 daily.
> Reduced Upfront Costs: Battery swapping allows drivers to purchase EVs without bearing the full cost of the battery, often the most expensive component.
I also wonder if it's a scheme to get people through the door and then leech off them with a lifetime subscription.
In the UK, where the OP is from, the equivalent of the battery you linked is available from Fogstar for £1850 (includes 20% VAT), shipped. Without the VAT that works out at ~$2000. A compatible high end 9kW inverter is available for around £1200.
The ROI is really attractive once you look past the overpriced kit.
I believe Chevy offers V2H on all 2026 Equinox EVs. Enabling this needs their V2H Enablement Kit and I believe you also need their PowerShift Charger. That would be around $38k for a 2026 Equinox EV LT, which has an 85 kWh battery, $6300 for the V2H Enablement Kit, $2000 for the PowerShift Charger. Installation via the company Chevy says to use is $2000-5000 according to the net.
That brings us to $51-52k, and would give 70ish kWh of usable backup capacity. That's around $750/kWh of capacity.
Getting that capacity with Powerwalls would require 5 of them and cost quite a bit more.
Plus, with the V2H approach when you aren't having a power outage you can use it as a car. :-)
I am writing this off grid, using about 15kwh of batteries and a $1200 (6kw) inverter. My entire system puls panels and racking those panels, plus wiring some un-powered shacks was about $10k, though I did the work myself (which would probably hae been another 3-5k if I could have found someone to do it.
> which would probably hae been another 3-5k if I could have found someone to do it.
Yo. If you can find an electrician to stop by my house and turn a light switch off for less than 1000$, please inform me. I got a quote for 25k$ to install a system that size, and that price. City code has me by the balls: I can't modify my main panel without inspection, the inspector won't show up without a licensed electrician, and electrician wants the labor. I pointed out that we're talking 8 hours of labor — call it 2500$, lawyer money — and he was like "what's your choice". I'm in Texas.
Ha, they actually messed up a bit and I had to repair a bit of the wall / wainscoting. Because of this they knocked $100 off of the price that I listed earlier.
To get a journeyman electrician license in Texas, you need to have 8000 hours of documented on-the-job experience working under a licensed electrician[1].
So you'd need to find an electrician who will let for you work them on the weekends, and if you work 8 hours every Saturday and every Sunday, then it will take you 500 weekends.
A residential wireman license only requires 4000 hours[2], but I'm not sure if that kind of license would be good enough for the inspection.
Isn't there an exclusion or lower entry requirement if you have a technical education like engineering degree? Like if not electrical engineering because I guess that would be obvious there should be lower entry bar - but for all others at least somewhat related...
I guess if you want to dabble with installing battery packs with inverters, that's not your typical bachelor of arts who is trying to do so.
Where I am at (rural CO), as long as it can be inspected and meets code, the county is fine- you don't need a blessing. Septic is different (that's a $175 certificate, though). But for electrical all you have to do is meet codes, which isn't really super hard.
This right here - I have been investigating getting my own contractor license for DIY work on a property I own that must be permitted but city will only issue permits to licensed contractors. Took a practice test for the exam on a whim and nearly passed it without studying. Anybody seriously considering DIY'ing the install of something like this probably could get a license without a lot of work.
From what I quickly checked you can modify your own home there is an exclusion for doing electrical work on your property - seems like main panel would be somehow excluded from what qualifies as "yours".
That exemption is from the state code and applies to "work not specifically regulated by a municipal ordinance that is performed in or on a dwelling by a person who owns and resides in the dwelling".
Hoss I am sorry to hear that- I have literally no idea what electrical costs, as I've been doing it myself. If you're living close enough to other humans that the can observe and complain, then we're not really in the same situation.
But that doesn't really change my point, does it? Like, if they are installing $6k worth of equipment and materials, then that's what the up-thread points was about paying 10K more for tesla-branded equipment, right? I get that at a certain point the labor makes the cost of materials less of a deal, but my point was that my battery+inverter+panels+material is still less than the equipment they are describing.
This is still not an accurate comparison. I'm not a Tesla fanboy but of all of the major players in the non-diy game (Enphase, Franklin, Tesla, Sol-Ark) they provide the best value for money, and are impressive pieces of equipment.
The EG4 18k has 11.5 kw backfeed capability, with a rather pathetic 65ish amp in-rush. Obviously 18kw usable solar capacity(they technically let you land up to 21kw, but only 18 is usable).
The Powerwall system you outlined can take 60kw of usable solar input, has 34kw standing backfeed capability, and a whopping 555 amp in-rush (not a typo, it's 185 amps per unit).
None of those things matter when your solar array is 4.5 kW and you have a standard 150A/200A grid in....
Like I said, they basically are not sold to scale like a normal household uses electricity.
EDIT: What the heck is in-rush and backfeed? Are you talking about AC input to charge the batteries? The 18k is 50A @ 240VAC (12kW) fyi. Also, why does the charge rate even matter there? For the AC output its also 12 kW...the family is average 48 kWh days, which is 2 kW hourly average...
Inrush is exactly what it says it is, it's inrush current. When you have a sudden surge on something, that's inrush. Lots of appliances in your home have a large inrush, much larger than the breaker they're on. Inrush happens faster than a breaker trips, which doesn't matter when you're on the grid and the inrush is lower than your mainbreaker, it matters when you have an inverter in the way with a passthrough limit and an inrush limit. Typical central HVAC units have LRA over 100 amps.
If we're talking about 'doesn't even matter with a 4kw array' well, hell, how the hell you gonna charge ~40kwh of battery with solar array that nominally produces 20kwh a day on its best day, assuming all conditions are perfect?
Backfeed is what the inverter can push out from the battery to the home. It's the size of the tube coming from the gallons of water reservoir. EG4 18k has a tiny tube, no matter how much battery you put on it. Like emptying a 50 gallon drum with a drinking straw(and with the 4kw array, filling it with a 12 oz cup).
> Inrush is exactly what it says it is, it's inrush current
These are not terms commonly used in the industry, thanks for the clarification.
> Lots of appliances in your home have a large inrush, much larger than the breaker they're on.
And inverters are designed to compensate for short term surges too fyi. The 18k provides 65A for a few seconds as an example.
> well, hell, how the hell you gonna charge ~40kwh of battery with solar array that nominally produces 20kwh a day on its best day, assuming all conditions are perfect?
Because you can't and don't need to...you should be asking the author of the original post, because they do what pretty much every other grid tied system which is that you pass through the power from the grid.
> Backfeed is what the inverter can push out from the battery to the home.
> It's the size of the tube coming from the gallons of water reservoir. EG4 18k has a tiny tube, no matter how much battery you put on it.
1. The 18k can push 50A on each leg and most residential are sized at 150a or 200A, which are ridiculously oversized, so at most, even with two EVs and a 4 ton AC running in Texas, I max out at 150A. I can put 3 18k's in parallel if I really want to and its STILL cheaper than a powerwall battery/inverter combo.
2. There is no reason to have a "pipe" so large that it only is used for less than 5% of the overall runtime. This is why the powerwall setup doesnt make any sense.
>These are not terms commonly used in the industry, thanks for the clarification.
It's such an industry term that it's literally a named feature on multimeters.
>The 18k provides 65A for a few seconds as an example.
Yes, you'll see I gave you that spec in the opening comment. It's not a good spec for a whole home hybrid inverter.
>the 18k can push 50A on each leg and most residential are sized at 150a or 200A
That's not how you read a spec sheet for 240v device. A home service is 200 amp, at 240v. That's 48kw potential. 12k is 12k regardless of whether that's (120v * 50a) + (120v * 50a) or (240v * 50a). The legs aren't cumulative. You're implying the standing load capacity is somehow higher than its inrush capacity. It would need to be a 24kw (on the ac side, all of the janky chinese rebrand inverters all list their DC input to try to make themselves seem bigger) inverter to do what you're implying.
(50a * 120v) + (50a * 120v) = 12kw
A small home with a smaller 150 amp service is (150a * 240v), 36kw.
Edit: screw it, I'll address this as well -
>There is no reason to have a "pipe" so large that it only is used for less than 5% of the overall runtime. This is why the powerwall setup doesnt make any sense.
There sure is! The whole point is to offset usage. 50 amp standing load capacity means you can only ever offset 50 amps of usage at one time. Sure, most homes don't hold anything higher than that for long but I've seen plenty of homes hold over 20kw for a bit if they have pool pumps, well pumps, pool heaters, or any number of things going on. Any time the home draws more than 12kw instantaneously you'd be getting charged peak rates, which could be avoided with a larger standing load capacity. In addition, if you're in a municipality with a 'demand' rate you could enter in to a different billing rate any time you go over a certain amperage, meaning that ability to offset more of that in that instance, even just for an inrush, could make an even larger difference on your bill.
Look man, I run an $800 chinese inverter, and my batteries are MuRatas I harvested from decommissioned Sonnen cabinets that I rewired with chinese BMSes. The Powerwall 3 is a really good product and the pricing is great compared to comparable non-diy consumer grade products. The EG4 is not a good comparison point because it has nowhere near the spec or capability. You would need 3 EG4 18ks to have the inrush capability of a single Powerwall 3. Battery capacity (volume) is not the sole determining factor in value. This isn't even relevant but just as an aside, the EG4 isn't even a good value for the DIY scene, and has functionally the same support as rebranded drop shipped Chinese inverters.
I'd love to know why you'd choose an EG4 18k (which is actually a 12k AC inverter, with a questionable track record on support and warranty) over a Sol-Ark 15k (which is actually a 15K AC inverter, and has tech support that responds) now that Sol-Ark dropped the price on 15ks to sub $5,000 MSRP.
I'd rather land wires in a Sol-Ark, it has better support, it has a higher AC output, it has a higher battery charge rate, and it's the same price.
Yes, 48 amps at 240 is 11.5kw. Each Powerwall 3 is 11.5kw(edit: not to be confused with its capacity which is 13.5 kwh, one is a power output, one is a storage capacity. Just so you don't go thinking that's some amazing mixup between the comments). The original comment is all within your framework of 3 Powerwalls vs one EG4 18K with 3 batteries. That's 12kw AC for the EG4, and 34.5kw on 3 Powerwalls. I've never stated a single powerwall has more output than that(hell I even rounded down on the output of the 3 powerwalls to 34kw), only that they have a very impressive inrush and solar capacity. The incongruity of the comparison between the two systems is the entire origin of this discussion. Do you even remember what you posted and I responded to? You don't know how to use an amp clamp and don't understand the American split phase power grid. Stop consulting ChatGPT for 'gotchas' and actually read what you're writing.
Just to be perfectly clear on your continued misunderstanding - each powerwall is also an inverter, it has its own AC power output. That stacks. The batteries strapped to the EG4 are all limited to going through the EG4. That means no increased output for adding more batteries. No stack.
With 3 EG4s in the comparison you would have a similar standing load capability(36kw claimed), however you'd still only have roughly 1/3rd the inrush capability(190 amps).
Honestly, I thought I started this conversation nicely enough and went out of my way to be informative and you've only tried to insult me and be snide while having the loosest grasp on the subject matter.
You keep throwing out specifications without understanding their real life installation use cases and then go as far as to make claims like "EG4 support is bad for DIY'r" which is so far from the truth it's hard to take anything you say seriously. There are hundreds of thousands of forums and YouTube videos from DIY who rave about EG4. In fact Sol-ark has a sketchy support track record (source - several installers I work with)
> The original comment is all within your framework of 3 Powerwalls vs one EG4 18K with 3 batteries. That's 12kw AC for the EG4, and 34.5kw on 3 Powerwalls.
And for the last time, you do not need 34.5kW continuous AC output for a house that is averaging 2 kW per hour per day. Yes, they have two EVs, but also these do not need to charge at their full potential if you plug them in every night. The author isn't generating enough energy from solar of their battery bank so it's pulling from the grid anyway for those loads, so a grid bypass (which EG4 supports up to 200A) means you don't need the inverter to pump out 34.5 kW to loads anyway.
The thing you keep glossing over is that the fundamental problem with a powerwall for scaling systems is that each battery bank you purchase requires you to purchase a built in inverter. The same nearly identical system from EG4 is an 18k + 15 kWh battery which costs $8k, and powerwalls cost $12k+. Thats a 50% premium to get you 185 LRA but 8 kWh less capacity. For an extra $250 you get an AC soft start and a 185 LRA is completed unnecessary and irrelevant.
> Yes, 48 amps at 240 is 11.5kw.
You keep saying these things like I don't understand the math.
> You don't know how to use an amp clamp and don't understand the American split phase power grid.
Lol. And you don't even understand that specifications ratings because they very explicitly say the amps at VAC ratings (120/240) because while it's entirely possible to reach the full potential of wattage... in real life, it's unlikely you will due to how split phase works with inverters. Inverters are rated by amps per leg because your loads on one 120v leg could be higher than the other one (unless all of your loads are 240v in which you would always be using the same amps on both legs).
So to conclude:
1. An identical system is $53k (Powerwall) versus $31k (EG4), which is still hilariously overpriced.
The only measurable differences are:
EG4 gets 6 more continuous AC amps (up to 1.44 kW more)
Powerwall gets much higher surge capacity (555A vs 195A)
EG4 gets 8 kWh more capacity
2. If you need more than 195A surge, you put a soft start in or just let the inverter bypass temporarily to grid.
3. You would never size this system with 3 inverters for someone averaging 48 kWh/day, so the author spent £7k on an additional battery and got an unnecessary inverter purchase which is now directly eating into his ROI.
>You keep throwing out specifications...
>And for the last time...
Well, neither of these are relevant to my original comment. I never commented on the value prop of the original install, only that your comparison in pricing is just not accurate as one is much more capable. Yes, lots of people want 34kw of standing load, because they want to ensure the offset of their HVAC unit. Generally people getting these systems have ridiculous homes, I've worked on a home with 3 20kw diesel generators. I've worked on a home with a seperate 200 amp service just for their pool side projector TV. Just because someone's wants aren't reasonable doesn't mean they don't want it.
>There are hundreds of thousands of forums and YouTube videos from DIY who rave about EG4.
EG4 sucks to try to pry anything out of. I don't actually like Sol-Ark that much either, but they're better to deal with and a better deal. Best deal is just to get an SRNE or similar straight from the source. Again, I paid $800 for my SRNE. I could get a second and parallel it and be outperforming the EG4 for a $3,400 discount. Youtubers are youtubers, not a source of truth. All those same youtubers shill battle born, too...
>Lol. And you don't even understand that specifications ratings because they very explicitly say the amps...
I'm not the one that has conflated two 50 amp phases with a 100 amp service. That's a 50 amp service. 12kw is 12kw. I keep repeating the math because you clearly keep misunderstanding it. A small electric range is typically on a 240 50 amp circuit, incredibly common in most households, and that's a small one.
>Identical system.
How is this identical? $5K for all other labor and materials? How much you paying per foot for the Class K to parallel the batteries? What's the homerun distance on the PV? Your AHJ require metal conduit on the DC runs inside the attic? Shit, if they require a 3R lockable lever disco that's $900 right there before fuses. What you penetrating with? What racking system you using? Shingle or metal roof? If shingle you doing the labor to pull shingles and put in flashing or you hacking it up with some HUGS/RT Minis? What's your max span between mounts given the wind load? S-5!s and HUGs add up fast when you can't get away with a large span. What's your interlock method? If you're landing in the MSP are you derating the mainbreaker? You value your time so little after all that material that you're still under $5k?
Edit: Also, you're gonna be paying a whole lot for LTL on that partial pallet of panels and 14' (if you get the short stuff) racking.
> Yes, lots of people want 34kw of standing load, because they want to ensure the offset of their HVAC unit.
The author of the post lives in the UK and averages 2kW load, a 4 kW PV system, and 45 kWh battery system. It's literally impossible for them to run a standing load of 34 kW for more than 1.5hrs without a grid tie. Why do you keep ignoring this?
That's not really apples-to-apples comparison. The Tesla batteries are AC coupled so they work with an (AC coupled) microinverter array. For a DC coupled battery you have to have a hybrid inverter and DC couple the batteries.
Your point that they are overpriced still stands though.
Ya as someone else pointed out, powerwalls essentially have an inverter built in. But this is really dumb to have inverters tied directly to each powerwall battery. This is like anti-scale.
A small thing I want to remark is that at that price, a Model 3 costs less than 3x, and has more than 3x the battery capacity.
Considering DC connectors on EVs provide a direct electrical connection to the battery terminal, and the charge-discharge circuitry in residential hybrid solar inverters can handle them just fine (provided it supports the voltage ranges, but people did this).
I think it's an enormous missed opportunity, that the most common charger standards don't support this (CCS2 doesn't, Chademo does, no idea about NACS)
If this was a thing, I think it would completely reshuffle the EV market, I don't know how used residential batteries depreciate, but I doubt they lose more than half of their value in 5 years like EVS do.
I'm talking about something a bit different - the Ioniq uses a V2L, which means it has an onboard inverter that generates AC mains voltage through the plug, and can be used to provide equipment directly.
What I'm describing is using the cars DC charge port and connecting it to inverters DC battery port.
For what it's worth, Tesla PV/batt inverters are bad, almost as bad as the Chinese manufacturers mentioned ITT. PW3 has very high failure rate ~10%+RMA, not good enough IMO to be in the path of power at my house.
(Their motor inverters are world-class, but totally different topology)
> everyone trying to fix the medical establishment is immediately called an anti vaxxer, science denier, etc.
That's because the thought leaders who are fed up with the medical establishment are gaining traction by spreading anti-vax and science denial ideas and not calling out specific medical establishment (other than "big pharma is a boogie man!"). So, it's hard to take their position seriously (even though, I too and anti medical establishment)
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