18-month $220k Powerwall solar energy installation nightmare
couriermail.com.au
couriermail.com.au
He is running beyond the scale of that Tesla's controller unit can really handle:
> Tesla soon worked out that the system was being overloaded due to having too many Powerwalls connected at once ... The gateway is being overloaded, reaching 100 per cent CPU and RAM usage. There’s too much info when they are all online.
He is doing something very uncommon among customers, and Tesla apparently doesn't even try to make it work:
> But while Tesla claims it can do off-grid 10-Powerwall setups, there are only a handful around the world – most are backed up by grid electricity, papering over any outages. ... “At the beginning there were actually only three 10-Powerwall installs in the world that were off-grid,”
They also apparently have poor support for off grid firmware updates, possibly related to the lack of CPU and memory to both keep the lights on and upgrade at once:
> “During these upgrade cycles, the system goes into this chaotic state that takes between four and eight hours, turning off and on 50 times,”
There was an internal market, and all services used had to be paid for. Sales people could keep everything after paying the company a cut and all the costs of delivering what they promised the client.
So if they over promised to get a sale, it all came out of their personal profit. Seemed to work quite well.
The entire company was structured as a set of internal markets though. Never seen anyone else do this.
$220K to offset a $10k/yr electric bill is a 22 year payback period, which is quite a long time if you are using energy bills as a rationale.
The primary rationalization for storage when you have grid access already is grid backup, and the secondary rationalization is for energy price arbitrage. Backup is hard to value monetarily because it depends on how much not having electricity costs you. Arbitrage is easy to value, but doesn't pay back much unless you have extremely variable retail electric rates.
> “The most confusing and contentious point for me is that Tesla seems to express that the off-grid Powerwalls cannot guarantee 100 per cent uptime … [but] this was never expressed to me during deployment, and had I known this, I would not have embarked on this journey.”
For a $220k installation maybe they wouldn't have been incentivized to explain it. One mode of the grid behaves a bit like insurance, increasing reliability and masking variability. Going off grid when you have the option to stay on seems like an irrational choice.
“Of that, $150,000 was from a South Australian government-backed solar loan, with another $70,000 in cash.”
There might be some subsidy in getting an attractive interest rate, but AFAICT, the article doesn’t say anything about that.
Of course here it’s not that simple because you’ll be replacing worn equipment at some point and you will have to spin proverbial plates to keep that working well.
I suspect this is about 3 parts financially sound and 2 parts Captain Ahab if you look at the full math.
I agree. I have a battery backup system too for similar reasons. However, I think that the operating cost savings start diminishing pretty quickly when you have to size a system to go completely off grid and simultaneously can't tolerate a higher outage rate.
That said, if you take the customers word, it sounds like Tesla Solar gave them the impression that they would have 100% off grid up time and didn't deliver on that due to their own inadequate equipment.
Maybe there’s an n^2 algorithm somewhere, maybe the hardware is simply underspecced. Maintaining voltage stability in a system without mechanical inertia (like a generator would have) requires incredibly fast response times, and a system like that should have been verified to actually achieve those.
From the damage that was caused, it sounds like there are no “hardware” fuses built into this system either. That alone should be cause for regulators to take the product off the market.
What a joke.
If anything maybe they should have a special power wall for large installations, with a beefier CPU and sturdier components.
It’s not uncommon in tech and even to an extent automotive for the premium model to stay one hardware revision ahead of the consumer unit and after a few recalls iron out the reliability problems, after the R&D is paid off on whales, bring it down market and introduce something new at the high end.
That’s both technologically sound and plays on baser behaviors of the well to do (namely, classism). If normal people have the same thing I have then it’s time to sell it so I can feel special again.
No, it just sounds like inverter, to which there are two devices connected, one which suddenly draws a lot of current (like starting power tool, possibly the one pictured in the article) and an "electronic device" with switching power supply. When the large current draw happens, the inverter tries to compensate which results in a lot of power transmitted over higher frequency (several tens kilohertz rather than usual 50 Hz). That higher freq bypasses input cap and fries switching power supply.
Matthias Wandel did a video about his own problems with portable battery setup, which did the same: https://www.youtube.com/watch?v=c1QSn3i_IEo.
This inverter is just not suitable for powering different devices. ISTM those different "offgrid" technologies are just not ready for prod.
Browsing the "top" posts of r/TeslaSolar, you start to get an idea for how much of a pain in the ass is to deal with the company once things go pear shaped.
I'm not sure if I'm surprised or not that Tesla engineers didn't stress test their system by putting like, 50 Powerwalls on a string and seeing if the system could handle it.
Maybe this could have been simulated purely in software. Not sure.
I think devs voted to get rid of them because it was often QA and Product ganging up on Dev, but if you’ve never experienced Dev and QA ganging up on Product, you’ve missed out.
Getting rid of QA meant that Product cannot be outvoted except by a walkout. It’s part of why I’m not as loud about DevOps becoming its own business unit. At least it’s 2 against 1 again.
If it can't handle 10 batteries and can't handle updates without backup from the grid, why did they make/sell this setup? Two controllers with ~5 batteries would make a situation where one is active/normal and the other is being the grid so the reliability would be the same as whatever they promise everyone else.. Similarly, he doesn't actually need to be off the grid, his connection just doesn't meet his peak usage so the level of chaos seems to be just to be able to say this is an off grid setup?
A cousin proudly showed me her solar setup at a vacation home including the app showing her electricity savings and the various hardware components and all I could think of was the things that can go wrong at our own property when I am not around and my parents, kids, or siblings are using it.
After serving as my extended family's "IT support" for decades and dealing with a neverending stream of headaches relating to wifi, printers, Nest, unresponsive PCs, TV settings, car apps, and so on, I'm wary of installing a major system that requires someone to be basically on call to deal with minor problems or major outages as described in TFA.
Also, the fact that the Powerwalls have processing overloads with 10 connected? Give me a break. A Nintendo Switch can coordinate with up to 11 other Switches in Mario Kart for a LAN party without internet.
"How I cut GTA Online loading times by 70%"
Nobody thought to implement this as two separate installs? Or the dad insisted it had to be done his way and is now mad that what he wanted didn’t work after they told him not to go that way?
They say doctors make the worst patients. I’m getting a hint of that here.
After a while, it feels less like "iterative" product development and more like "highest bidder gets the feature" development.
It does work that way. I work for a unicorn security firm that internally has the rule that a bug impacting a business that pays less than 10K a year cannot be fixed. They are to be strung along until they quit on us.
Whether we are actually working on the issue we claim to be working on entirely depends on your ARR. If you are a customer with less than 10K ARR, your bug is not getting any attention from engineering, just endless promises from support.