Adelaide dad’s $240,000 18-month Tesla Powerwall nightmare

[Bud]

There are huge pieces of important information missing from the article, mostly what is using all that power!

Seems he may be running some computer equipment

...he has lost at least “three or four weeks” of full-time government IT consulting work.

[EEVblog]

Answers to questions:

[EEVblog]

Haven't watched it, but an update from a year ago:

Looks like he's doing mining:

The South Australian government has fantastic solar backed loans (150k), I have a business premise for my IT Business + home on the same property + are mining Chia Coin, Ethereum and Strayacoin.
Presently we have an ongoing consistent load of 5kW per hour via 240v supply (Austraila).

I still come back to the main issues of power outages, it was crazy to disconnect from the grid when he didn't have to. He's into home automation and has custom load controllers. He could have kept the existing grid for the base load and used the solar for some peak load. And he could obviously disconnect the crypto miners.

[johnboxall]

Five minutes of googling would have found him a professional system such as a dropbear or copperhead plus a genset for rainy weeks. And he could have a direct line to the designers in Australia. 

https://redearth.energy/products/copper-head/

[EEVblog]

Five minutes of googling would have found him a professional system such as a dropbear or copperhead plus a genset for rainy weeks. And he could have a direct line to the designers in Australia. 
https://redearth.energy/products/copper-head/

Yeah, so many other options, and several of them local. For issues of this scale if it was a local company it's likely the designer would have personally come out to investigate.
Who uses a Tesla for off-grid of this scale? It's aimed at high end grid connected homes.

[EEVblog]

My guess is that he saw the government loan program and figured:
a) that he could go absolutely crazy installing an insane system that would provide free power for the crypto miners (and other stuff of course)
b) Save cost on the grid connection upgrade if he simply went completely off-grid, which in theory should have worked.
c) The crypto profits would pay the loan back and he gets a free (or muc lower cost) kick arse solar system
d) Chose Tesla because he's a fan

But crypto has collapsed and he's stuck with a hideously unreliable system few if any people had experience installing on such an off-grid scale.

From the Yotube video description:

We decided to embark on a journey with a government backed $150,000 loan through our business with majority of the consumption going to business operations.

This involved Solar Lab (solarlab.net.au Justin & Max leading the install) who have done a stellar job, super impressed the install is seriously beautiful, it's my 4th solar install and these guys are second to none, the best customer support and the most attention to detail, the whole crew are just great.

In all honesty, Tesla Australia have also been fantastic to deal with, the predicament being the system is just not ready as advertised. We have an offgrid setup with 200 panels (70kW) wired into 8 Fronius inverters totaling 200 amps @ 240v into the batteries via Tesla Gateway and a Distribution Board. The entire schematic, wiring was endorsed by high level Tesla Tech's.

We've been advised this issue since June/Julyish is being looked into and we're not the only installs finding complications and it has been referred to as the Can Bus causing sync issues/lag/delay. I've also developed a Python scrypt to download over 1 million metrics (50 per second) via ethernet to the Gateway to see what occurs, some examples of what the Tesla Gateway is reporting can be seen below (watts) (Agh!! I can't share images here, I need to create a youtube video and go over everything)

Summary
We have 70kW of panels funneled into 50kW of inverters, charge cycles have no issues
It's the discharge issues that can occur at any time, we have had Solar Lab out for the last 8 hours and we now have 2 batteries online in hope that it will stabilise for now whilst we get Tesla back on the phone tomorrow (it's 11PM and Solar Lab just left) they were offering to connect us back to the grid /rewire for free but my concern is it takes the whole off grid configuration setup into a grid connected direction which doesn't allow Tesla to configure our end game product (Off grid 10 powerwall install).

They offered to reconnect him to the grid for reliability but he didn't take them up on it. Why? Because he seems to want to dick around with an off-grid system and make it work. 

[bdunham7]

a) that he could go absolutely crazy installing an insane system that would provide free power for the crypto miners (and other stuff of course)

I actually mined crypto for a few years using my surplus solar power, since Edison only paid a pittance for the year-end net surplus.  I don't see why going off-grid would help that use-case as the money would be better spent on more solar and less backup, allowing for the crypto operation to suspend if the power goes out.  I had mine timed to automatically ramp up during low power cost times and idle otherwise.

[EEVblog]

a) that he could go absolutely crazy installing an insane system that would provide free power for the crypto miners (and other stuff of course)

I actually mined crypto for a few years using my surplus solar power, since Edison only paid a pittance for the year-end net surplus.  I don't see why going off-grid would help that use-case as the money would be better spent on more solar and less backup, allowing for the crypto operation to suspend if the power goes out.  I had mined timed to automatically ramp up during low power cost times and idle otherwise.

It was a government loan, so he didn't have to pony up all the cost up front. Maybe figured the crypto profits would repay the loan and bingo, cheap system.

[nctnico]

a) that he could go absolutely crazy installing an insane system that would provide free power for the crypto miners (and other stuff of course)

I actually mined crypto for a few years using my surplus solar power, since Edison only paid a pittance for the year-end net surplus.  I don't see why going off-grid would help that use-case as the money would be better spent on more solar and less backup, allowing for the crypto operation to suspend if the power goes out.  I had mined timed to automatically ramp up during low power cost times and idle otherwise.

I agree. It would be interesting to know what he paid for the Tesla powerwall batteries. If he paid the price that is listed on Tesla's website, then he is looking at a price around US $0,50 per kWh just for storage costs. But likely he didn't read the fine print about the warranty and expected usefull battery life.

[james_s]

It was a government loan, so he didn't have to pony up all the cost up front. Maybe figured the crypto profits would repay the loan and bingo, cheap system.

I've been saying for years that the collapse of crypto was not if but when, and if the economy goes down the toilet crypto will be completely worthless rather than becoming more useful. It has always felt like a fad, I'm kind of shocked it has gone on as long as it has. I hate to think of all the gigawatts of energy it has consumed and millions of tons of carbon it has released into the atmosphere.

[Black Phoenix]

It was a government loan, so he didn't have to pony up all the cost up front. Maybe figured the crypto profits would repay the loan and bingo, cheap system.

I've been saying for years that the collapse of crypto was not if but when, and if the economy goes down the toilet crypto will be completely worthless rather than becoming more useful. It has always felt like a fad, I'm kind of shocked it has gone on as long as it has. I hate to think of all the gigawatts of energy it has consumed and millions of tons of carbon it has released into the atmosphere.

Totally true, but a lot gone for the easy money - making money from nothing, and some done a ton.

I have a family friend who was my neighbour here. His wife left him for another man and he said screw it.

He sold his apartment, quit his Tencent job and moved to his hometown in rural China. There he rented a warehouse and for 7 years (during the boom of Bitcoin and Etherium) invested in equipment and mined 24/7, taking advantage of the cheaper energy prices of his prefecture.

When things staring coming down, he sold all his investment and coins, made a ton of money, got married again with a childhood girl from the same town and moved back to Shenzhen.

He now lives in a Mansion in Yantian, close to the mountains (5 min away from me), his wife have a law degree done in the US (she's a consultant for international companies wanting to do business in China) and him being an IT guy open his own company also providing consultancy (I've done some work for him in laying cable and server racking and configuration).

Currently he is waiting for the first kid and have a better life that he only could dream about some years ago. But for his sucess case a ton of failures exist worldwide.

[tszaboo]

That's probably the worst designed system that I saw in a long time. What's that, 10 x 5KW inverters?
Took the pricing of the 5KW SMA sunnyboy: 1300 EUR, 25KW SMA sunnyboy: 2600 EUR. Instead let's spend 2.5x as much on the inverters, and let's have a lot of them. The more the better. I want more of everything.
Hybrid inverters? No, what's that. Let's have a separate box, right next to the inverters.

This was a guy, taking up useful solar incentives ordering an oversized, under engineered system so he can use it to mine a crypto fad (because Chia was that) that was pumped by chinese speculators. Now that his fake coin dumped from 1600 USD to 30 USD, he is desperately trying to get back out of the hole that he dig. First rule of crypto investment, don't invest that you cannot lose.

[electr_peter]

Ignoring monetary aspect, from technical point of view it is really not optimal to construct higher power system from small components when one bigger would do. It is like attaching 5 small trailers to a passenger car to move some stuff instead of renting mid size cargo truck.

[EEVblog]

That's probably the worst designed system that I saw in a long time. What's that, 10 x 5KW inverters?
Took the pricing of the 5KW SMA sunnyboy: 1300 EUR, 25KW SMA sunnyboy: 2600 EUR. Instead let's spend 2.5x as much on the inverters, and let's have a lot of them. The more the better. I want more of everything.
Hybrid inverters? No, what's that. Let's have a separate box, right next to the inverters.

Yeah, I would have gone with hybrid interters each with their own battery system (or even just some of them), all independent but grid connected.
In subirbia here in Australia the grid is pretty darn reliable. A whole house AC backup is nice to think about having, but so rarely needed that it's silly to even try at this scale. Just have an emergency power outlet and wiring for emergency items in case of power failure.
This is why only remote properties have off-grid solutions, because they don't have the grid. And hardly any of them use Tesla, as there are heaps of robust proven large scale off-grid solutions available, several of which are aussie designed and made.

[nctnico]

That's probably the worst designed system that I saw in a long time. What's that, 10 x 5KW inverters?
Took the pricing of the 5KW SMA sunnyboy: 1300 EUR, 25KW SMA sunnyboy: 2600 EUR. Instead let's spend 2.5x as much on the inverters, and let's have a lot of them. The more the better. I want more of everything.
Hybrid inverters? No, what's that. Let's have a separate box, right next to the inverters.

Yeah, I would have gone with hybrid interters each with their own battery system (or even just some of them), all independent but grid connected.
In subirbia here in Australia the grid is pretty darn reliable.

I'd imagine that at high power levels the inverters will have trouble to keep sync with a grid connection which can transport several times less energy than the installed solar system.

edit: fixed typo in bold

[EEVblog]

That's probably the worst designed system that I saw in a long time. What's that, 10 x 5KW inverters?
Took the pricing of the 5KW SMA sunnyboy: 1300 EUR, 25KW SMA sunnyboy: 2600 EUR. Instead let's spend 2.5x as much on the inverters, and let's have a lot of them. The more the better. I want more of everything.
Hybrid inverters? No, what's that. Let's have a separate box, right next to the inverters.

Yeah, I would have gone with hybrid interters each with their own battery system (or even just some of them), all independent but grid connected.
In subirbia here in Australia the grid is pretty darn reliable.

I'd imagine that at high power levels the inverters will have trouble to keep sync with a grid connection which can transport several times energy than the installed solar system.

Why is that? What's the difference between 10 houses on a street with one hybrid inverter each vs 10 on the same house in terms of sync?

[Circlotron]

If his average power draw was <4kW

And that 4kW would eventually end up as heat. Must have a lot of ventilation happening. I wonder how noisy his property is when going full swing, both from the ventilation and the devices consuming all that power?

[nctnico]

That's probably the worst designed system that I saw in a long time. What's that, 10 x 5KW inverters?
Took the pricing of the 5KW SMA sunnyboy: 1300 EUR, 25KW SMA sunnyboy: 2600 EUR. Instead let's spend 2.5x as much on the inverters, and let's have a lot of them. The more the better. I want more of everything.
Hybrid inverters? No, what's that. Let's have a separate box, right next to the inverters.

Yeah, I would have gone with hybrid interters each with their own battery system (or even just some of them), all independent but grid connected.
In subirbia here in Australia the grid is pretty darn reliable.

I'd imagine that at high power levels the inverters will have trouble to keep sync with a grid connection which can transport several times less energy than the installed solar system.

Why is that? What's the difference between 10 houses on a street with one hybrid inverter each vs 10 on the same house in terms of sync?

The impedance of the cable feeding the houses. The cable that runs through the street from which the homes a branched off will be much thicker so no real problems there. The impedance of a cable designed for -say- 63A might be too high to sync 200A of hybrid inverters. Even when most of the power is consumed at the location of the solar panels AND the power fed into the grid cable is limited, there still is a very low impedance, local node where the hybrid inverters push their power into.  At least this is something I'd thouroughly check.

BTW: fixed my typo in my text. It seems you have interpreted the sentence correctly though.

[Someone]

That's probably the worst designed system that I saw in a long time. What's that, 10 x 5KW inverters?
Took the pricing of the 5KW SMA sunnyboy: 1300 EUR, 25KW SMA sunnyboy: 2600 EUR. Instead let's spend 2.5x as much on the inverters, and let's have a lot of them. The more the better. I want more of everything.
Hybrid inverters? No, what's that. Let's have a separate box, right next to the inverters.

Yeah, I would have gone with hybrid interters each with their own battery system (or even just some of them), all independent but grid connected.
In subirbia here in Australia the grid is pretty darn reliable.

I'd imagine that at high power levels the inverters will have trouble to keep sync with a grid connection which can transport several times less energy than the installed solar system.

Why is that? What's the difference between 10 houses on a street with one hybrid inverter each vs 10 on the same house in terms of sync?

The impedance of the cable feeding the houses. The cable that runs through the street from which the homes a branched off will be much thicker so no real problems there. The impedance of a cable designed for -say- 63A might be too high to sync 200A of hybrid inverters. Even when most of the power is consumed at the location of the solar panels AND the power fed into the grid cable is limited, there still is a very low impedance, local node where the hybrid inverters push their power into.  At least this is something I'd thouroughly check.

BTW: fixed my typo in my text. It seems you have interpreted the sentence correctly though.

I thought the point was this person/setup in question was entirely off grid, so had no external sync.

[EEVblog]

The impedance of the cable feeding the houses. The cable that runs through the street from which the homes a branched off will be much thicker so no real problems there. The impedance of a cable designed for -say- 63A might be too high to sync 200A of hybrid inverters. Even when most of the power is consumed at the location of the solar panels AND the power fed into the grid cable is limited, there still is a very low impedance, local node where the hybrid inverters push their power into.  At least this is something I'd thouroughly check.

Sure. You'd upgrade the capacity to the street, or maybe just not have as much solar installed. Or maybe have an independent battery system for extra loads. Or...
There were plenty of options and he chose the one that would be most likely to give him power outages if anything went wrong. And then struggled with it for a year and half, and refused a free reconnection back the grid when offered to sort out the power outages.

[John B]

The impedance of the cable feeding the houses. The cable that runs through the street from which the homes a branched off will be much thicker so no real problems there. The impedance of a cable designed for -say- 63A might be too high to sync 200A of hybrid inverters. Even when most of the power is consumed at the location of the solar panels AND the power fed into the grid cable is limited, there still is a very low impedance, local node where the hybrid inverters push their power into.  At least this is something I'd thouroughly check.

Sure. You'd upgrade the capacity to the street, or maybe just not have as much solar installed. Or maybe have an independent battery system for extra loads. Or...
There were plenty of options and he chose the one that would be most likely to give him power outages if anything went wrong. And then struggled with it for a year and half, and refused a free reconnection back the grid when offered to sort out the power outages.

Yeah but 0.135MW of off-grid battery and solar is some giant e-peen.

[tszaboo]

That's probably the worst designed system that I saw in a long time. What's that, 10 x 5KW inverters?
Took the pricing of the 5KW SMA sunnyboy: 1300 EUR, 25KW SMA sunnyboy: 2600 EUR. Instead let's spend 2.5x as much on the inverters, and let's have a lot of them. The more the better. I want more of everything.
Hybrid inverters? No, what's that. Let's have a separate box, right next to the inverters.

Yeah, I would have gone with hybrid interters each with their own battery system (or even just some of them), all independent but grid connected.
In subirbia here in Australia the grid is pretty darn reliable.

I'd imagine that at high power levels the inverters will have trouble to keep sync with a grid connection which can transport several times less energy than the installed solar system.

edit: fixed typo in bold

When the inverter is producing power, it increases the voltage. It has a voltage limit built in, so if the voltage goes 230V+5% (or whatever the local voltage standard is) then it reduces the output power to stay within the limit. This is a legal requirement for all inverters. Now, if you have 10 inverters in parallel, then suddenly you have 10 control algorithm fighting against each other to export as much power as possible. I don't think I need to tell you why this is a worse than having two inverters trying to do the same. Number of poles and zeros in a control system?

That's probably the worst designed system that I saw in a long time. What's that, 10 x 5KW inverters?
Took the pricing of the 5KW SMA sunnyboy: 1300 EUR, 25KW SMA sunnyboy: 2600 EUR. Instead let's spend 2.5x as much on the inverters, and let's have a lot of them. The more the better. I want more of everything.
Hybrid inverters? No, what's that. Let's have a separate box, right next to the inverters.

Yeah, I would have gone with hybrid interters each with their own battery system (or even just some of them), all independent but grid connected.
In subirbia here in Australia the grid is pretty darn reliable.

I'd imagine that at high power levels the inverters will have trouble to keep sync with a grid connection which can transport several times energy than the installed solar system.

Why is that? What's the difference between 10 houses on a street with one hybrid inverter each vs 10 on the same house in terms of sync?

There is a non negligible impedance between those inverters, dampening the system. What you end up with is: The house closest to the feed is going to export 100%, and the one further away will export 0%.
I've seen the math on this. I was working on a project years ago, where the idea was to control this excess power to generate imaginary currents and stabilizing the grid. Controlling the inverter with RS485. This "too much sun" is a small issue in Belgium, I think it was estimated that 5% of the installations loose more than 150 EUR per year because... the grid operator refuses to upgrade the cabling or transformers.

[madires]

The maximum voltage for feeding the grid is 230V *1.1 = 253V over here. If this voltage is exceeded inverters have to shut down to prevent damages. The resistance of the local power distribution grid and each building's power connection helps to regulate things within limits. Besides that, the electricity supplier (or operator of the local power grid) defines how much kW can be fed in by each PV system without overloading house connections or the local grid. But wIth heat pumps and EVs I'd guess that we have to upgrade the power grid anyway.

[trobbins]

One aspect of interaction can be the mechanism that the PV inverters use to determine there is a valid grid to feed into.  As an example, SMA PV inverters afaik use a technique that stops exporting power for a short portion of a mains cycle, and monitors the response of the grid during that time to confirm a valid connection.  That 'disturbance' from the PV inverters caused an unforeseen oscillatory kVAR response from co-located battery inverters in a grid connected system.  The response was related to the number of battery inverters on-line, and was able to be somewhat alleviated by modifying the control system of the battery inverters, but not stopped.

I'm not aware of what technique Fronius use, and in this Tesla system it looks like there are unresolved issues without any PV involved.  But it may not take much to alter a stable operation used by the manufacturer to confirm acceptable operation, compared to field installation differences coming into play (like as suggested the different distances from the common AC bus to each battery inverter - as compared to placing the distribution bus in the middle and using equal length feed cables to each battery inverter).

[nctnico]

One aspect of interaction can be the mechanism that the PV inverters use to determine there is a valid grid to feed into.  As an example, SMA PV inverters afaik use a technique that stops exporting power for a short portion of a mains cycle, and monitors the response of the grid during that time to confirm a valid connection.  That 'disturbance' from the PV inverters caused an unforeseen oscillatory kVAR response from co-located battery inverters in a grid connected system.  The response was related to the number of battery inverters on-line, and was able to be somewhat alleviated by modifying the control system of the battery inverters, but not stopped.

I think that in the end synchronisation to the grid by using the grid itself turns out to be a less and less useful method for solar inverters (and other distributed renewable energy sources). At some point a seperate synchronisation signal will be needed (and no, not through something wireless you can jam/spoof like GPS). Grid operators in the US are already looking at resillient ways to synchronise devices feeding the grid.