448 How to Build an On- and Off-Grid System (Backup Box Hack, Huawei SUN2000, LUNA2000)
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- Опубліковано 16 жов 2024
- Unstable power grids, planned shutdown of electrical power, or even blackouts: How can we prepare our homes and home automation systems against such events? Today we will cover these topics with the eyes of an engineer, and I will show how I protect our home against short and longer outages.
In part one we protected our homes against short outages. Today, we will protect them against longer outages. I will focus on my PV, but also show how you could use an ordinary emergency generator.
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Thanks a lot for sharing this solution, Andreas. Basically you can go off grid on demand and perhaps just get a gas stove for cooking. Wonderful!
Indeed, the gas stove is waiting for the outage…
This is such a satisfying solution :) It was always a shame in my opinion that so much power is available in emergency situations, but not usable
I assume newer designs will integrate these possibilities right from the factory. Solar sill is in its infancy...
Your single phase to multi-phase back-up hack, works for two phase countries as well. My electrician thought I was crazy until he thought about it.
It also took us some time because it is a bit "out of the box" for a decent professional.
I had a solar system put in about 8 years ago, but because I was in the middle of a construction project (and had young kids at the time), I didn't take the opportunity to learn enough about the various tradeoffs. If I had your diligence and taken your structured approach to learning, I would have avoided a lot of mistakes! What has helped me learn was the installation of a much smaller DC-only system with some panels I got cheaply later - nothing quite like building it to learn.
Thanks for sharing your knowledge and experience!
I agree, I always have to use projects to learn! Reading book does not create enough questions for me .
Very clever solution. Thanks to Andreas. If somebody needs an motor driven generator, consider also a "tractor power axel driven generator". Old tractors are very realiable motors, and generators can be transported at the hook-up levers at the back of the tractor.
Good solution if you have a garage for the tractor ;-)
Indeed, often reffered to as PTO: power take off.
In some country side districts there are several old tractors in barns or open field with a minimal cover blancet. They use their new tractors with 200 hp + 1,7 m front&back tyres also for school trips daily (15 years is enough to drive these monsters).
If you have some loads on a UPS (like several outlets fed by a 1000W UPS), fed by some larger batteries that give you some time, you could just feed those batteries with DC from any source, tractor or just an engine or a car, then let the UPS switch back in with the grid and put up the tractor at your leisure. A little automation is required if you don't plan to stay home all the time.
astonishing!!! the lengths we go to keep America happy and afloat!!
I do not understand :-(
MANY THANKS to you Andreas! I was always wanting to have an independency option for my PVs and your solution inspired me on a way to go! Besides the Backup Box, I ordered similar automatic electricity switch from AliExpress (I have a monophasic 3.65 kw SUN2000 + 15kw LUNA battery) and spent few days to correctly arrange all wiring with an electrician. One conflict we noticed is that the system refused to work if a General (not the main entrance) switch was ON on the system. It was conflicting with the one switch on the Backup Box (I guess) so we had to turn it off permanently. Finally the system started to work as on your video, what a relief!
Greetings and thanks for sharing :)
Vladimir (Portugal)
Glad it works. Here, unfortunately, I never had the chance to "really" use it because we had enough eletricity during winter ;-)
A nice solution for already existing system and I'm glad it works for you.
For a bit more than a price of Huawei inverter + backup box you can buy Deye 8kWt hybrid inverter that can provide full-power 3-phase output in off-grid mode. Also Deye inverter supports unbalanced load, so up to 50% of nominal power (4 out of 8 kWt) can go to the load of one phase. Deye uses low voltage 48V batteries which are more universal comparing to proprietary HV batteries. Also Deye has Smart Load output which is designed to prioritize self-consumption over grid export, fir example by dumping excessive solar energy into a hot water tank. Of course that would be a different build, however total price would be similar, wouldn't require external transfer transfer switch, would provide full-power and correct 3-phase output.
It seems that Dye has a good product. I did not know it. However, as I said in my videos, I wanted a high-voltage battery.
And, as an engineer, wasting eletricity to heat water , is a no-go, too. I rather sell it for a cheap price to the community. Electricity is more valuable than 60C water. But charging a car battery would be a perfect application for this function.
I like the 3-phase problem's solution. Well done.
Thank you!
Hi Andreas. I did quite similar things with a transfer switch with the exception that I use a 1000VA USV with external 24V batteries as Voltage source and I cleaned up the phases such that all I want to power ( light, freezers, IT and heating (just 35W for control and pumps) is supplied on one phase. This makes me sure that no dish washer, washing machine is powered in off grid mode thet may lead to overload of the backup power supply. I hacked the APC USV such that it self start when supplying 24 V. This needs just some sequential button presses which I realized with an Attiny controller. So everything is now fully automatical and work without manual interventions.
Cool! So your system is similar to a emergency generator, just without using fuel!
Here, we wanted to power the whole home, not only the critical systems with solar because in late February/March when they predict potential power outages, the sun should already produce enough energy for everything (except cooking). So we should be able to live a "normal" live.
As a UK resident, I envy your 3-phase supply. We only get one phase in domestic installations. But I suppose that implementing your solution would be much easier.
Indeed, you could save two phases of the switch. And the backup box would be simpler (and probably cheaper).
I feel that our situation (just 1 phase) is more convenient. No complexities, simpler wiring, you don't have to think how to balance load, etc...
If you need three phases, you can pay for a three-phase supply, but it make your life more complex.
I guess, I wouldnt have had the balls for the test of the full electrical instlalation, to be honest. Respect, Andreas.
I also double and tripple checked and waited at least one day before I had the courage of turning the switch;-)
Thanks, very interesting.
My proposed solution is Sunsynk 8.8kw hybrid inverter, Freedom won 10kwh battery and 7.6kw solar panels - lack of space forces the limit. Everything is single phase and the sunsynk takes care of switching between loads so connection is relatively simple.
I already invested in Huawai. And I need 3 phases in our home...
@@AndreasSpiess I understand. Sorry. Should have been more clear that I'm just sharing what I'm about to put into my own place as contrasted to your installation.
Very interesting solution. Here in Italy, residential customers are usually suplied with single phase 230VAC, so this type of setup would be even simpler to adopt.
Indeed, single phase systems are simpler in many respects.
Hi, many thanks for your inspiring project.
It must be noted that, at least in Switzerland, any modification to a house wiring requires the neutral regime to be of TN-S type due to differentiel protection requirements (FI or DDR). Older houses (like mine) were often connected using TN-C (1 wire for both neutral and protective earth PE).
No modification to the wiring is allowed unless it is changed to TN-S, so there is no way to setup an Off-Grid backup System. This can be quite costly. So my Huawei SUN2000 will still stop when Off-grid, until we find an economical solution (maybe just setup part of the wiring to TN-S, while having the rest of the house still on TNC, and getting no current when OFF-Grid).
Thank you for your information. Unfortunately, I do not understand your problem ( I am not "fluid" in house installations). This is why I trusted my electrician and hope, he got it right. There are also FI fuses in the backup box, BTW.
Earthing and wiring schema is a thorny topic, there are also lot of regulations involved
@@AndreasSpiess it's quite easy your Outlet have free wires going to it live, Earth and neutral and his wiring only has two wires - no extra earth pin
The Backup Box manual from Huawei explicitly forbids connecting to TN-C grid types. However, if the household is wired as TN-C-S then it is perfectly fine. You can't switch to TN-S unless the power company does it for the whole neighborhood supplied from the same source in your area, which would be extremely expensive. The cheaper option would be to change your TN-C system to TN-C-S system where you split the source Neutral(PE) wire into two at the power distribution box at your house. Of course this must be in correspondence with your country's electrical regulations. Another way is to convert to a TT system where you install separate earthing system for your house getting a completely independent protective earthing while you use the source Neutral(PE) only as Neutral. This again must be advised with your local electrical regulations.
Engineering and science rocks! This is awesome.
Thank you!
Thank's a million, I have ordered the transfer switch which, looking forward to testing this :-)
Hope you enjoy it!
I recorded "here is the guy with the Swiss accent" onto a solar powered recorder. So I can get a smile on my face even if power goes out for weeks.
Cool! ;-)
You may use a VFD (variable frequency drive) to solve the 3 phase problem. Many of them can be supplied by 1 phase + neutral and output 3 phases + neutral. You can also set the VFD to various parameters. This is usually done to power motors.
I agree. But in my home, this would be a solution without a problem ;-)
Nice addition to your solar system, great this works.
Thanks 👍
Hallo Andreas. Ich wurde durch einen gemeinsamen Viewer auf Dich aufmerksam gemacht. Unser Swiss-Alpöhienglisch hat offenbar parallelen 😀 Wowww, dein Kanal ist ja gigantisch! Falls Du mal eine tolle Idee hast, wie man ein Schweizer Taschenmesser mit deinen Skills aufmotzen/umbauen/ergänzen/abändern/elektrifizieren oder was auch immer könnte, lass es mich wissen. Wäre spannend mal eine Zusammenarbeit mit Dir zu machen.
Liebi Grüessli vom Bodäsee
dä Felix
Hallo Felix,
ich kannte deinen Kanal noch nicht (nun hast du aber einen Subscriber mehr ;-) .Ich habe ja früher immer mein Taschenmesser für die Mailbags verwendet und da hätten wir einen Ansatzpunkt. Allerdings ist diese Videokategorie nicht mehr so beliebt und deshalb habe ich schon lange keines mehr gemacht.
Meine Zuschauer haben sich beklagt, dass mein Messer Stumpf ist...
Hallo Andreas. Deine Antwort hat mich sehr gefreut.
Vielleicht gibt's ja mal ein Video mit einem micro GPS Trekker ... oder irgendwas in Richtung Funk.... oder Photovoltaik auf der Griffschale... die springende Idee ist mir bislang noch nicht gekommen. Lass es mich Wissen, wenn Du eine tolle Idee hast. Wenn ich mal was baue in mit Elektronik, werde ich Dich mal anfragen ob das spannend sein könnte für Dich.
Liebe Grüsse
Felix
The transfer switch is the key.
Not only. I think, all parts are needed...
This is how all Solar installations should be installed rather than sitting there usless during a power outage.
I agrree.
@@AndreasSpiess There's some safety concerns. If the power is cut so workers can operate on the lines?
@@cmuller1441 the inverter is already detecting grid power loss, so instead of turning itself off why doesn't it just cut the connection to the grid?
@@35manning An increasing number of inverters do just that. In the US, most notable are SMA and MPP, both of which have options for daytime backup without batteries.
Great video, thanks for sharing. I like your approach "take responsibility"
Thanks for watching!
Nice. That's how I protect and provide the IT@home. :)
Thanks.
You're welcome!
Hi Andrea, maybe I missed it but did you consider a Hybrid inverter. You could check the Growatt systems. I use a SPF5000ES, only 1phase but you have 3P options aswell. The only drawback this system does not netmetering (export to grid) but new hybrid systems with this option exist. All switching from grid to inverter is automatic, the inverter is disconected from grid, If you use correctly sized batteries for storing sunpower 'you are good to go'. just my 5cents. Thank you for your great videos! You inspire! 73
My inverter probably is called „hybrid“ ( I do not know the exact definition). It uses solar, manages the battery, and provides 3phase power to my home.
A hybrid inverter does the switching between sources automaticaly. source 1 = PV, 2=battery, 3=grid/disel agregat
@@Phoerixx my Multiplus also have a transfer switch, but if you have a 3 phase at home and only one phase inverter, you have to use an external ATS
From my experience with my install. Basically the same as yours without the transfer switch; the backup output from the backup box is always powered; even when the grid is up.
In my case (three phases), this would give a big short-circuit. So you are lucky you can do it without transfer switch.
Very interesting. Ideally I would have liked to see what happens when grid comes back. Also, I would like you to have identified the "two breakers in seroes" that the electricity suppliers requires - presume one is the changeover switch and the other is part of the Backup Box.
Having the breakers in series reduces the risk of sticking contacts, thus injecting power back into the grid. He showed them in the schematics.
Nameless ghost is correct. And the switch back is without effects. The transfer switch takes a few milliseconds to automatically switch from backup to the grid. You hardly see it.
Wow, it looks like you know how to party! 🎉 I'm so jealous of your fancy setup; it sounds like you'll be set for any power outages! Thanks for sharing such a cool project. I really like how you've put your whole house (almost) on backup mode.
I'm purchasing a 3-phase hybrid inverter (Solis) with backup mode. According to the datasheet, the AC backup port is also 3-phase, which can switch to battery in 40ms in the event of a power outage. I'm not sure how this inverter can be integrated with the whole house. I might need to implement your solution later on.
I also do not know if they are certified to be used on public grids.
In Canada we have much the same problem. My plan will use a generator but the only legal way to do it is with a transfer switch and you need to mind the grounding when doing a whole house application as opposed to backup circuits. I only have two phases and can jumper them with an adapter to my generator.
A generator is a good and simple possibility!
Hello ANDREAS. Can you share an electrical diagram/scheme with us for your solution on- and off-grid system with Huawei components? Thank you in advance. Great video and keep up the good work.
I thought it was quite evident in the video. I do not have a diagram :-(
Having solar and the grid being down was a major source of consumer outrage in Florida after hurricane Dorian (2019), without power being restore for a week, or more. Personally I'm learning that Swiss have 3-phase power supply to residences. Many regions of world only have 2-phase power. Thanks for sharing your learnings.
In Florida, my system would probably be more valuable ;-) I was there after a Hurricane and saw what it did. Not nice!
In Europe, quite a few countries run 3 phases to residential buildings.
Great content ! So the UPS will take over the grid when its goes off ? Is there a special UPS for that?
If you mean the UPS for my lab: It was an Eaton. But it was defective after a short time...
Super video, really enjoying my front-row seat!
Thank you for your kind words.
Great video! For a 1-fase house, can we just enter the grid on the backup box and exit the whole house on the backup load?
I think so. But you still need the switch that switches the backup power to your home.
Great video, very interesting, but one note of caution...
With star-wired 3-phase, the neutral cable may be only the size of a single phase or even smaller, as a balanced load will have no neutral current and most 3-phase devices will have neutral current less than a single phase current (because the three phase angles sum to 0 and the neutral only carries the imbalance).
However, you now have all three phases in phase. That means the neutral current will be the sum of the phase currents, so the neutral may be overloaded. I don't think you mentioned that, so take care to check the neutrals are appropriately sized.
I agree. But my inverter only delivers the power of one phase if in off-grid mode (3kW). So it should be ok.
Thanks Andreas for this pretty interesting hack.
You are welcome!
Be aware of those chinese ATS. I know mant people reporting reliability issues using it. Thanks for your amazing work making these videos
Others said the same. I got a 3 phase model instead of one with 4 and Aliexpress refunded the whole amount. So I will do some reliability tests on my bench...
Have a look to Sungrow hybrid inverters (e.g. SH10RT). They have the backup box and transfer switch functions integrated and can deliver 3 phases on emergency power.
hybrid inverters are the way to go. all you need in one box. don't install something else or be prepared for blackouts !
A hybrid inverter is not enough as I showed in one of my earlier videos because it has to switch off (by law) when the grid is off. The SH10RT is the same as my Huawei and needs a STB5K backup-box. It also only provides "emergency power" (info from the homepage of Sungrow)
@ulistermclane You are right, and I was wrong. The SH10RT has a Backup box built-in. Still, you would need the trick with the switch if you want to feed your whole home (or connect everything to the backup line, which is probably ok because it is very strong). The price is also very ok.
Please take a look at the Deye/Sunsynk inverters
I hope, I will not need another inverter for the next 10 years or so ;-)
Consider exploring Victron equipment. MQTT, ModbusTCP and Node-RED is native to the ecosystem. Your changeover will be within 20ms.
My colleague uses Victron and is happy with it. Have to keep mine for the next few years...
I guess the delay comes from inverter start-up in off-grid mode, where it takes time to switch the system and supply electricity. Backward switch to grid is nearly instantaneous. I guess and switch relay will have the same delay to do the mentioned process.
Does the transfer switch back automatically to mains power once the grid power is restored ( after a suitable delay ) ?
Yes. I connected it this way.
Hi Andreas
1) Where is the Huawei smart power sensor located in the setup?
On the grid side of the Automatic Transfer switch?
2) Is the any circuit breakers or relays on the grid side of the ATS? Like a EHFI relay?
3) I assume the grid meter is on the grid side of the ATS?
4) Since the SUN2000 gets its power from the house grid, which in your case is powered by the backup box when off grid, can that be the reason it still powers the inverter allowing the solar panels to provide power for the house grid as well charging the Lunar2000 battery?
Because Huawei states only the L1 inverter can run in pure off grid mode, not the M1 you have (and I). The M1 supposedly only allows the battery to provide backup power…
For me, if the SUN2000 does not charge battery and run house on solar when off grid, backup box is not much use.
So I am really curious how you made it do it!!!
Best regards from Denmark
The Smart meter is on the grid side. There is no need for it if off-grid. As said, my inverter charges the battery in off-grid (Huawei info is probably outdated).
The rest of your questions should be answered in the video.
Thank you very much for that super hack :) but would be possible to get more detailed your connection drawing ? Or maybe even video ?
I do not plan a next video and think, an electrician should be able to draw the needed diagram.
Interesting exactly what I need , I want to make my own back up box , do you know what the signal/ voltage is given from the original backup box to the inverter to fire it in back up operation?
No. I assume the backup box just has a relay contact.
Hi Andreas, I love you solution and like to test your creativity!.
We have a home with
3 x 10k 3phase inverters with each 15kw batteries and 3 backupboxes (66pv panels).
The house is powered by 3 x 400V+N (32amp) and inside the house evrything is cabled on 3 times 230v , we needed the 400v for heating pumps and the Electric car.
How would you propose to power the house and combine the 3 backup boxes mono phase 230v and create
1) 3 phase 230v
or even
2) 3 phases 400V+N
Any solution is good (UPS, transformator or recabeling)
Thanks for your creativity
Alex
I do not do consulting (too dangerous). I only show my findings in my videos. But I am sure, with the understanding of what I did, you will find the right way for your situation that is legal and working. Your situation is basically the same as mine. The only thing is that I had to do a trick because I only had one phase to power 3 phases.
As I am not really an electrician I have some issues in understanding the ATS-wiring (to be able to discuss with my electrician). My understanding: Source A (upper area): Phases 1-3 are not connected, just phase and neutral on the green connector from Grid. Source B (lower area, upper connector): The phase from the backup-box is connected to phase 1 and also to 2 and 3, right? The green connector is connected to phase and neutral from the backup box. The lower connector on the lower area is the output to the load.
Yes. The Huawei inverter only provides one phase. But I wanted light in all rooms. So I connected this one phase to all phases.
Hello Andreas. I'm new to solar and thought this video was very interesting. I'm just wondering why you are investing this amount of money for something a 1000€ petrol powered generator could do, during a longer blackout?
As you, I like things simple, so my plan is to use solar to complement my grid. No batteries, no inverters, no big investments, only solar DC to DC load. Small investments, but still a system that continues to work when the grid goes down. That happens 1-2 times/year here in Sweden and it never lasts longer than a few minutes.
As I said, I'm new to solar, but my plan is to use the sun and solar panels to power pumps and resistance wires to heat up my pool, cook food, heat my house and run my water heater. This will work in theory and I'm gonna try to make it work. Simple and cheap solutions.
I really like your videos, so keep up the good work 👍
The backup solution was a hobby for me. Not needed in Switzerland (like in Swiden)...
@@AndreasSpiess Ok, I understand. Thanks for the reply
Very interesting, thankyou. I enjoyed watching it.
You are welcome!
I believe two important things should be noted for this solution:
1. In this way you connect the whole house load to the backup system. This means the house load should not exceed more than 5kw for LUNA2000(10-15kwH) or 2.5kW for LUNA2000(5kwH). Shorting the three phases means that you support the whole house load and some households may exceed the 5kW(2.5kW) limit which would cause the battery short circuit breaker to activate. Most three phase stoves can operate with a single phase, excluding the oven. This means having only 1-3 burners turned on (or maybe a boiler) will get you close to the 5kW(2.5kW) limit.
2. The L1 terminal in the backup box and source A terminal of the ATS switch should be connected to the same phase. Otherwise in cases where a single phase drops, due to a short circuit break from the sourcing power distribution box for the household, you may get unpredictable behaviors. One scenario is where an inverter goes into off-grid mode but the ATS switch does not transfer to backup power, leaving the household powered with the remaining phases from grid. Another scenario is where the inverter enters alarm mode due to missing a phase for proper operation in grid-tied mode, but the missing phase is not the one that triggers switchover to off-grid mode, this way the ATS switch may completely shut down power to the house although you can power the house with the remaining phases.
I agree.
I have worked a bit with UPSs in hosting servers and datacenters and connecting a UPS to a UPS (daisy chained) is a hard no-no as it can cause critical failures, and seeing that the solar inverter and battery is on a sense working as a UPS here; One threat is that the current draw can cause the upstream UPS to go into an overload condition or distort the output voltage waveform. When this occurs, it can prompt the UPS to detect a power fluctuation, revert to battery power, and continually cycle between the battery and normal operation. Plugging one UPS into another can also spark inverter compatibility issues, where the unit closest to the load doesn’t recognize the other UPS’s power as sufficient. This compels both UPSs go to battery, defeating the intent. Daisy-chaining can also force UPS controllers to work against each other, leading to harmonic distortion on power lines.
So... you might want to make sure that this is not that case in your scenario.
Thank you for your input! I am not sure how much your scenarios apply to my case. My small UPS for the computer and the network only consumes about 300W ( constant load). The PV inverter can supply 3kW in backup operation. So I hope that the influence of the small UPS on the inverter is not big enough to create problems. And the small UPS does (hopefully) not care where it gets the energy from. What do you think?
i plan to use 3 victron inverters, so i whould get 3 phase power even during a grid fail (we need 3 phase to run our wood based heating systems and some other important things).
The viscron inverters have the benefit of supliing power without any downtime at all (like offline ups). You can use any Solar inverter with them, only thing you need to make sure is the inverters need to have more capacity than the solar inverter. Once the battery is fully chared the vicron inverters rise the frequency to 51hz to disable the solar inverters.
My colleague has a similar Victron system. He is happy with it. I think, he has a low-volt battery (or batteries), though.
Hello Andreas, I have at the moment also a SUN2000L1 so only one phase, without battery or backup box, and my parents are also asking for a solution when the grid goes off.
You got a really good price for the 10 kWh and the backup-box, I think now it is much more expensive.
I think that a better solution is to buy an off-grid inverter that accepts non proprietary batteries, I am thinking about a Growatt with Pylontech batteries, this inverter will be connected between the Huawei and the house and will work as an UPS when the grid is off, without the delay that the Huawei has. Of course no hack of the electrical network will be needed.
I needed an on- grid because it’s main purpose is producing energy for our home and sell the rest. We produce 5x what we need in the summer months.
@@AndreasSpiess I have also on-grid and already injected a lot, but instead of Luna + Backup Box + Hack + UPS I want to use a Growatt + Pylontech. Much more KISS than your approach imho. I guess you didn't know that the Huawei has that 3s delay when commuting from on-grid to off-grid?
maybe since DIY self storage isnt practicle, combining all the extra solar energy could make it more practical, to say move a mass battery, a huge rock that spins, having like 50 solar connections hooked up to it all giving their extra energy to spin it where on their own couldnt do it, then this spinning mass will be slowed down to use the energy in the winter, obviously would this be a net gain is something a little math would figure out quickly, but other than pumping water, no long term solar storage really exists...
@@bbogdanmircea I do not know which particular products you look at. Just ensure your inverter or battery can do all the needed off-grid switching.
@@mikejones-vd3fg We can store a lot of electricity in our alpine lakes. But for the moment, I do not care too much about it. We still burn lots of gas and coal during spring/summer/autumn. If we can replace that part, we already have something... For the rest, we have a few years left. And as an engineer, I am confident that innovation will not stop.
Yesterday weve installed a 200kw diesel generator at our company in bern. Just for worst case situations.
Slightly bigger than my installation ;-) But it is scary that we have to do such things in Switzerland.
Depending on the purpose, it might be wise to add a battery pack to close the gap between grid switching. Power generators have a small startup time and a small period of time to produce a stable output. Larger installations and critical infrastructure are not pleased with a delay of 1,5s. The batterypack kicks in first and as soon as the power generator produces a stable output the grid switches to the generator. Very reliable, very expensive too.
Very interesting, usefull and entertaining. What else? Btw, at 5:38 you metioned that "old motors" won't work in a star configuration because of the rotating field. However, by useing the Steinmetz circuit (adding capacitor to create fase momentum) it is possible. Of course with the downside of losing a lot of power/torque from the motor. I had to come up with this solution several times (air compressor, no 3 phases available). It is however a emercency solution that I would not recommend.
With some Variable Frequency Drives it is possible to power smaller 3 phase motors with one phase.
@@olafvanes Indeed, there are plenty of those on AlieExpress etc... Usually for smaller motors. Their price is quite reasonable.
@Philip: As you know, I forgot all these things during the years because I hardly touch more than 12 volt systems. But good to know in an emergency situation.
@@AndreasSpiess I'm very fond of 12V systems too and I'm replacing 230V circuits where I can with 12V (or 24V). This goes very well for everything related to lights. Makes it handy for battery backup and legislation is much easier.
@@PhG1961 My radio room (with the exception of the PC) works on 12V, too. But the lab is on different levels... 12V is really very simple: Just connect a LiFePo battery and it works...
Hello Andreas, thanks for your videos. I have noticed one possible problem with connecting 1 phase to 3 phases and it is possible overloading of neutral (blue) wire on appliance connected to 3 phase to star. If phases of AC are shifted by 120 degree, as from grid, than in balanced load there is no current on blue wire and in worst unbalanced case there is same current as maximum on each phase wire. Therefore blue wire has normally same (or smaller) diameter as phase wires. If all three phases are conneted to one though, there is no shift, and on blue wire current will be 3x phase current. As this is how my water heater is connected (3 phase to star) i have been thinking about current on neutral wire an it is freshly in my mind. As you do not use electricity for heating, this is probably not an issue for you, but it is important in general, as this could lead to serious overheating of blue wire if used for longer time. I hope this is not already mentioned in other comment, but there are too many.
In principle, you are right. However, my inverter only delivers 5kW. So there is no problem with that. Plus to save (precious) energy when the grid is down, I do not use such high-power applications.
Hallo Andreas, super Idee, ich überlege das auch umzusetzen. Ich hoffe, dass Ihre Schaltschrank Innenleben normalerweise mit eine auf Maßgeschnittene Abschluss-Deckel auch geschützt ist, sonst ist es sehr gefährlich die Sicherungen oder diese Schalter zu nutzen, da blanke Kontakte zufällig zu berühren sind. BTW: ich folge Ihre Kanal seit Jahren, habe sehr viel von Ihnen gelernt und umgesetzt. Weiter so! :-) Liebe Grüsse aus Ungarn!
Ja, der Schaltschrank ist normalerweise abgedeckt!
Hi Andreas, thinking from a DFMEA-perspective: If you ever have an "oh-sh*t" moment (electrocution/fire/etc.) and need to kill power to the house, won't the inverter be a try-hard and override your "main power off" action? How can you easily kill main power in your meter-box , in such a situation?
Surely there's a second fuse box after that one that has RCDs and stuff, so he can cut off power from there
In most houses (as is the case in his) you have a RCCB/RCBO switch in the circuit. I assume that his failover solution is before said switch, so if he needs to cut the power to the whole house, he could use that switch. Maybe the transfer switch also has a manual override, too.
I have a fuse right at the inverter that I can switch it off manually. And the one I used to cut-off the grid.
Correct me if I'm wrong but Star connected motors supplied from 1 phase will overheat immediately, the currents will be the LRA (Locked Rotor Amperage) and the system will overload the inverter 🤔 ....... Star connected resistive loads can "overload" the neutral wire if they are too high, but if they are small loads I do not see that much problem
The problem with star motors is well possible. I do no more remember these topics from my EE studies ;-)
Nice hack. However I still would try to have priority loads on separate line/phase. Because you know... power of habits. Especially if you don't have any constant "alarm"/indicator that grid is off.
With out 10kWh battery and solar charging also in off-grid mode we could live our life off-grid during a big part of the year. So it is not too critical.
I guess the same idea could also be done with an electric car equipped with vehicle2load. That is usually a few kW output, but not sure if it can be automated and wired to be always ready when the car is plugged in. And another thought. Maybe 3-phase equipment can be wired to have supply only from grid, as that would guarantee no odd behaviour if all phases are shorted. At least heat pumps etc are probably best to isolate like that. Otherwise a very innovative idea!
So far we have no vehicle2load here. So I did not look into this matter...
This video does not mention, is the Smart Meter (DTSU666-H) also required for this solution to work? In the wiring diagrams I am seeing this as an integral part and also in your video when looking at the fuse box it is present.
As all grid-connected systems it needs this smart meter, you are right.
hello Andreas, you should be happy that you live in Switzerland. In Czech republic due to stupid rules of goverment subsidies, batteries and inverters from major suppliers now costs 2x more than in other countries in Europe
That is bad news!
@@AndreasSpiess Yes, it is very sad, unfortunatelly these types of regulatory problems is not uncommon in east europe countries. 10 years back almost no small rooftop instalation get permission to supply into grid. But big solar parks on the fields get permission without problem. Also since 2011 electricity consumption is measured for each phase separately, so for household instalations we need inverters with asymetrical output instead of symetrical which are common in most other countries.
I just get offer for PV system from 2 biggest companies here, for example they want 8k-9k euros for 10kWh battery, goverment subsidies for battery are up to 4200eur, but is limited to 10kWh and 50% of purchase price. DIY installations are not allowed (only exception is full offgrid). Not even all electrican are allowd to do it. Only electricans with special PV certificate can install PV systems connected to grid and subjected to subsidies.
Hi Andreas, maybe also good to mention, that 99% of the ovens can be supplied with a single phase. If you have a single phase at the installation place, there are metal bars, which bridges L1,L2 and L3. But in your case you bridged them right away - so your oven would work without any problem :)
That depends on where you live.
@@marvintpandroid2213 probably right :) in my case Germany
@@marvintpandroid2213 In the UK domestic supplies are only single phase in nearly all houses, so Ovens and hobs come with L1, L2 and L3 already linked.
@@pjaj43 I have fixed a quite few domestic ovens in the UK and never seen the ability to be used in 3 phase enabled either externally or internally and then lnked out.
I have seen that on some US domestic units but then only 2 phase.
I have only ever seen 3 phase on industrial kit in the UK.
I only switched the oven and the stove on in off-grid and they did not move. Then I switched them off and was happy that nothing was damaged. I anyway never wanted to use them during such a situation (I have a small gas cooker for real emergencies ;-)
Greetings from the other side of switzerland. I now have the same setup as you with one exception, I have a manual transfer switch from ABB. My power outage test was together with the electrician inspector. Funny thing was that the luna was still charging during the test because the sun was shining and there was plenty of power available from the pv. How much do you spare for power outage? I configured 20% or 3kWh.
For the moment I have 95 and 10% as limits. But mainly because I want to extend the life of the battery. I only will change it when I see something changing in the overall situation of our grid.
BTW: We already had an outage when I was not at home. My wife did not know that there was one ;-)
Maybe I misunderstood something... the SUN2000 inverter runs 3-phase when the grid is connected, but only 1 phase in backup mode? Or is there a second inverter for the grid-tie operation? This is one case where I'm glad we split one phase here in the US... much simpler household electrics! 👍
Yes, the SUN2000 inverter runs 3-phase when the grid is connected, but only 1 phase in backup mode (explanation in an earlier video). This is the reason for my "hack".
Das ist ja mal ein richtig gutes Video, richtig genial gelöst und kommt zum richtigen Zeitpunkt für mich. Habe einen Growatt Mini 4600 XH mit einer 7,2 kWh Batterie und einer Backup-Box und war am Grübeln wie ich, das hier in einem Dreiphasenhaushalt realisiere. Danke. Bin so froh hier vor einiger Zeit bei diesem Channel die Aboglocke gedrückt zu haben. Danke
Haben die growatt nicht einen AC Ausgang? Zusätzlich zum AC Eingang der normalerweise zum Einspeisen verwendet wird? Der Ausgang müsste doch dauerhaft mit Strom versorgt werden, und dann kannst du ja das ganze Haus darüber anschließen
Ich bin froh dass das Video nützlich war. Wir hatten einige Zeit mit denken verbracht bis wir diese Lösung hatten....
Great video as always. We have decided to go for a full turnkey system with three phase offgrid possibilities (next year). In Sweden, we have a "green subsidy" that is capped at 50k SEK per person, so there's no batteries this year since the subsidy is eaten up by the main solar panel installation.
I would have loved to do a more DIY solution, but we find ourselves with more money than knowledge, so that's our route. The DIY part I'll be when I try to integrate the geothermal heating we're also installing this year and the solar stuff into Home Assistant. Perhaps I will make a short series of it and upload it on my channel - if I can get my ass out of the trolley (Swedish proverb) 😀
Cool. So you have a lot of work in front of you. But it is very rewarding to produce your own energy!
WOW! You guys have 3 phase in your homes. Here in North America homes are connected to 1 phase with a transformer that has a center tap. So homes have single phase 240V or dual 120V half phase, from a "hot" to ground, supplies. Most (99%) loads are 120V to ground, only stoves and other heating devices are 240V. I'm not sure if you can even get 3 phase brought into a house, and if you can the price would be ridiculous. 😃
Your country is much bigger and you would probably need more copper;-)
I usually just see 3 phase (US) for businesses: retail, food, etc. Most residential poles only carry 1 phase {7200V or so) after you get a relatively short distance from the substation. I'm always amazed at the small wire I see in boxes overseas when I have several circuits w/ #6awg on them and 4/0 coming from the utility meter.
The caveat is that those houses have 240v-Neutral on their outlets where ours are 120v. A #14 wire there carries nearly double the power for the same current.
Our system provides 400V from phase-to phase...
@@AndreasSpiess and that would make about 230V phase to N. 👍
My Fronius Symo GEN 24 8.0 is also a Hybrid Inverter like yours. It supplies 3 phases and up to 3.7 kWh per phase and max 8kW (for my version) in total. And strangely, Fronius claims that the off-grid mode must only be used for max. 20% of the total life time of the device. Why? Cooling? Market segmentation against more expensive off-grid solutions. But the best of your solution is the switching time: For my Fronius the siwcthing time (the time without power) about 90s. Your switching was very fast. I do not understand the technical reason for the 90s delay in my case. But anyway, the long term problem is solved as well. I like concrete information about devices, like in your videos, very much.
I know why they wait for the 3 seconds here. The electricity company wants that the inverter waits till the breakers are "really" open. Only then, the "off-grid" signal must go to the inverter. An it needs a short time to start.
90 seconds seem to be rather long... And I did not read anything 20% usage. However, our inverter delivers 8kW in on-grid and only around 3kW in off-grid.
@@AndreasSpiess Yes, waiting for 3 seconds to make sure the mechanical switches did their job is ok. The 90s smell like they want to skip any short power outages which are less than 90s and do not want to go into off-grid mode for short periods of time. But I do not understand this. And yes, the inverter also restarts in my case. But that should not take 90s. I think the market for the hybrid inverters is still developing and we will hopefully see better products in the next years. I mean, you could easily imagine an UPS-like switch within a half-wave. That would be a killer feature since it would further simplify the setup and that would certainly be worth some money. (I hope some manufacturer reads this. 🙂 )
I am set to buy a solar backup system. which include the following - HUAWEI 3.68 KTL M1 Hybrid Inverters and 3 x 5 KWh Batteries with Back up Box. My house has three phase and I was wondering if, in case of a power grid failure, I would be able to light up different appliances on different phases (but same house).
Apologies for asking to you directly but this is a huge investment for me, we do have a number of power outrages here and I don’t fully trust the salesmen
I answered this question in the video.
@sSpiess apologies for my ignorance but I am really not a technical person. Once again sincere apologies. I only want to keep an AC, fridge, kettle and freezer switched on
Andreas I was waiting for this video since summer when you said you would post this off grid safe idea! Thank you! Any idea if instead of using LUNA batteries, we could use DIY LiPo batteries with Huawei Sun2000 series?
I would not do it because they are high voltage batteries (800V). If you want DIY I would go for a different brand.
Sali Andreas, danke für das tolle Video. Heute wurde endlich die Installation der PV-Anlage inkl. Backup Box B1. Ich glaube ich habe sogar die gleiche Anlage wie du. Bei der Abnahme waren der Elektriker und die Solarinstallateur dabei. Sie waren sich nicht einig, ob die Backup Box für mich sinnvoll ist oder nicht. Ich wäre froh, deine Meinung dazu zu hören.
Elektriker meint, dass die Backup Box speziell gesichert werden muss und aufgrund der Limitierung von 16 Ampere nichts bringe, währen der Solarinstallateur plötzlich der Meinung ist, dass ich gar keine Notstromanlage benötige. Tatsache ist, dass ich gerne bei einem Stromausfall einen funktionierenden Kühlschrank, einen Tiefkühler und warmes Wasser habe (das letzte wird wohl mit der 1-phasigen Backup Box nur wie bei Dir mit der "short circut zu Phase 1 möglich sein). Super cool wäre eine direkte Konversation dazu, wenn du Zeit hast. Danke schon mal und beste Grüsse, CJ
Es sollten alle Angaben die du brauchtst im Video sein. Ob du eine solche Anlage willst oder nicht musst du und nicht dein Installateur entscheiden. In der Schweiz ist sie vermutlich kaum nötig.
I have five UPS units from that company, you'd be wise to have a spare battery on the shelf for when you unexpectedly need to replace the one that came in the unit. The cheap aftermarket ones are as good or better than the originals too.
Thanks for the info. For the moment, I sent it back for repair or exchange. We will see...
yes these ups batteries are always failing after 3 years max (less for entry level models like this one...) just keep one 12v battery as a spare...
Great idea. Thank you.
You are welcome!
Cool, i'm from Algeria, and i have a similar situation to yours when it comes to the distribution of loads and phases, each phase is going to a different floor, and heavy loads and lighting/light loads are mixed, i wish i could rewire everything to separate them but it will cost and take much effort
i also spent tons of money on 17Kwh OPzS batteries, and a victron Multiplus 5KV inverter (i've yet to buy extra 2KW panels in addition to the old 1KW )
i'm currently reading about classic control to build my own custom ATS to fulfill my needs, with open option to use Arduino to add some complex logic to the system
At least you should have much more sun than we have ;-)
Your battery is quite big for a 1kW panel, BTW.
@@AndreasSpiess yes, planning to get extra 2KW, have more cooling loads in summer, usually the AC stay on at night in July and august
@@AndreasSpiess the reason i bought the batteries before the end of last year and before solar panels was inflation, while solar panels price go down every year even with inflation
Hello ,
Are the ports for the neutral conductor on terminals X1 (backup load-port 2). X2 (grid-port 4) and X3 (Inverter-port 8) at Backup box-B1 at the same potential?
From which port is the neutral conductor connected to the switch (which you suggest) for the load? (X1 port 2 or X2 port 4).
The network is of the TT type.
Can you draw a three-pole diagram?
Thank you
Miletic from Serbia
I do not have more information than shown in the video. Look at the drawing at 6:29 that shows the whole setup. Backup power is the single-phase output of the inverter.
I‘m using the same chinesium transfer switch, but for backing up my oil heater with a power bank. They are quite amazing for their price - but i‘m not sure if i‘d trust them to put my house on them…😬
I have no experience. But they will not be used often...
12:04
Are those live uninsulated bus bars connecting bottom terminals of devices on 2nd row, aren't they?
The bars connect the phases to the fuses.
Can you give some details on wood burning heater you mentioned? And any plans of sending its brain dump to iot platforms?
The wood heating is at a remote place and it heats many homes. The Huawei integrates neatly into Home Assistant.
Are the stove and oven really connected in delta? It doesn't seem the case here in Australia where 3-phase supply is used to balance the loads by connecting different elements in star...
I was also thinking it would be delta until I read some appliance installation destructions. Seems like they don't want to deal with the higher voltage.
I did not check. The just do not work off-grid. So I supposed they are connected in delta.
Great as usual
Thank you!
I have a question. Do you think this system would work without grid connection at all ?
Regards,
Benoit
I would use a different inverter for that purpose.
Ok danke schön @@AndreasSpiess
Is this Hager main switch you operated to simulate a grid loss foreseen to cut power under load ? IMHO it is only an isolating switch, normally you have first to switch off all the minature circuit breakers to remove all the loads.
I do not know. But my loads are usually only 500W distributed on three phases...
3:54
A working internet without a power grid?
What is your DSLAM, your cable provider modem
or your 4/5G BTS in the neighborhood is running without grid on the street?
I do not know if and how long it would work. I had some power outages (some even caused by me) and therefore decided to add a UPS anyway. But I agree, in most cases, the internet will be dead when energy is off.
I don't know about the Helvetic confederation but here in EU (I mean Greece) the domestic circuit connected to the grid has to be certified by a technician. This implies that every single devices such as the transfer switch has to be CE compliant which i doupt it is when you buy it from AlliExpress (I may be wrong, please double check by yourself). Siemens sells one but it's above 1000€ here. The Hager model is 813€. The Chinese one is only 36€ 🤔Something tells me that the price tag is not just due to the CE sticker.
I do not know, but the professional Electrician installed it. In this application, it is not very critical. Nothing dangerous happens if it does not switch and if it connects the grid to backup while the grid is on (which is a very strange failure mode because it switches between the grid and backup), we get a dead short across two phases (because they are connected) and will trigger the fuses.
@@AndreasSpiessI didn't say that it was dangerous, I said I have no idea why the price tag is so high and maybe it is for other reasons than safety. Maybe reliability? Maybe it's the EU specifications that makes it expensive to produce? Lack of mass production? I don't really know.
@@srfrg9707 I also do not know. But in my case, I hope it will never be used (or just a few times a year). I assume there are other use cases. 1000 Euro for a simple two-way switch seems a lot to me anyway...
CE is self certifying....the companies grade themselves, it is the most nothing of all standards. A kid could set up a lemonade stand, write CE on the side, and it would probably pass...you know, since the kid would be the one deciding if it did or not.
@@srfrg9707 On Amazon user review I found an interesting hint about the potential issues with this switch. It is not (always) switching as fast as promised and no guarantee that all phases and neutral switch synchronously. This could cause an issue if the neutral switches later and is not connected for few milliseconds while the mains are already connected. This is mainly an issue when switching back to he grid with 3 phases, as in such case there could be >230V if the sources on the the three phases are quite unbalanced load.
_Great!_
👍 - _also_ for the YT algo! 😊
👍 - _auch_ für den YT-Algo! 😊
Thank you!
Thanks again and Congrats! Paralleling all 3 Phases could overload the neutral line of loads in star configuration. But during power outage, cooking will be done by a camping gas cooker.
Your solution is very unexpensive. The battery is way less expensive than my BYD HVS. And your Backup-box is quite fast.
My Fronius Gen24 supports 3 phase backup. But it needs an expensive backup box und the transfer is slower than yours (German rules, I think). Otherwise my small Victron backup solution for the heating system has UPS speed.
The Victrons seem to be very fast. A colleague has a 3 phase design and is happy. When I ordered our inverter I did not think that I ever will think of a backup solution. For normal operation, my inverter/battery is extremely cheap ( and is LiFePo4 and high voltage). All deciding factors. one year ago...
@@AndreasSpiess The backup idea was the starting point for me in 2021 after reading the report of the Bundesrechnungshof anticipating the issues and after the elections. But I hesitated too long because I wanted to avoid 3000 EUR for a new main distribution box in my >50 year old house (crazy German rules). And I wanted to have a 3 phase Victron system. But here, there is no company installing this. So, I ordered in March 2022 a "standard system". Then, all was delayed until autumn. In autumn our government decided 0% VAT for PV beginning from 2023. End of january the system was installed but I have to wait until the meter is replaced by a two directional one..... Long journey
@@klassichd10 Indeed. We were lucky, and from the order (24.2.22) to the first energy (26.5.22) was fast. The counter came in June. But I still do not have a valid invoice...
@@AndreasSpiess But you have your "own" electricity. Fast and inexpensive, lucky man. Virtutis fortuna adjuvat. Great DIY team.
@@klassichd10 Indeed. Being a UA-camr might have helped a bit ;-)
Hi Andreas, I love your lessons. The transfer switch has a green connector on A and B side label NO NC AR AN. I didn't find any documentation on aliexpress about them. Please let me know if you have any information about them.
I had to test its behavior out on the bench first to be sure. And it comes with a diagram.
Hallo Andreas.
Tolles System. Es gibt jedoch ein System von SMA, dass in etwa gleich Teuer ist. Zudem hat man den Backup Teil direkt im WR integriert und hat 10kVA auf drei Phasen zur Verfügung. Lediglich die Batterie ist minimal Teurer, da man an BYD gebunden ist. Als Installateur habe ich gute Erfahrungen damit gemacht. Jedoch draf man nicht den 300mA Fi vergessen, da die WR im Backupmodus den Kurzschlusstrom nicht erzeugen können, den die nachgeschaltenen Sicherungen benötigen, um fachgerecht zu Funktionieren. Aber auf jedenfalls coole Anlage. Vileicht sieht man sich ja mal. Ich Wohne keine 300m von dir😉
LG Basil, Solar4you
Den Namen Holinger kennt man natürlich in der Gegend. Und wenn man auf die Homepage geht sieht man auch den alten Herrn (dein Vater? ;-)
Komm doch mal für einen Kaffee oder ein Bier vorbei. Du findest meine Telefonnummer sicher.
Hi. Fantastic Video!!! I was trying to do exactly what you did in the video since one month and I got the backup box and the switch from aliexpress. No electrician I consulted in Spain was able to give me a solution. Since I am not really knowledgeable in electric connections I didn't have the guts to try it. Can you please tell me how to connect the one Phase going out from the backup box to the 3 phase switch (or short circuit as you called it) this key connection is hidden in 8:00 of the video. Thank you in advance
The backup power cable is connected to all three phases of the Transfer Switch. But ask an electrician if you are not sure (or if it is illegal to tinker in this area as it is here).
Also here, the idea did not come from an electrician ;-)
@@AndreasSpiess Thank you
Hello Andreas, thank you for your interesting videos. I have one question about the automatic transfer switch. If the grid is switched back on in case after a blackout, it is not guaranteed that voltage/frequency are 100% stable. Wouldn't it make sense to switch back to the grid after a while? If you switch back too early you could damage your devices with under/over voltage. I see advantages here with the manual switch. Many greetings!
You are right, it could make sense to wait. But I compared it with the "normal" situation where my devices are directly connected to the grid. Then, they also would get all the instabilities.
Guessing you chose the Huawei inverter because it works with HomeAssistant OS, but can it be restricted to a VLAN with no internet access?
I assume it works without internet. Then, you have to do the updates with your Smartphone. And you can connect it with a wired Modbus.
I showed why I bougt it in earlier videos.
I am a bit confused about whether your approach enabled you to use the stove/oven in the end, and I wasn't sure how to interpret some of the comments below on it (referring to VFDs). Was it not the goal to have the stove/oven powered? Or was the goal just to not destroy them while powering everything else? If the former, are there limits on how long you'd reasonably be able to run these appliances for, in an extended off-grid scenario?
I never planned to use the ovens and only wanted to make sure they are not destroyed. Commenters wrote that these stoves should not need 400V from two phases and therefore should work.
Because the panels work in offgrid, it depends on the sun how long they would last.
@@AndreasSpiess Thanks for the response. I thought that the ability for the solar + battery system to deliver sufficient current to the stove would be the limiting factor in keeping the stove running, not necessarily the power generated from the sun. Is this the wrong idea?
@@danielsmullen3223 In offgrid, my Huawei delivers up to 3.3kW. But this discharges the battery fast and you have to set priorities if no sun
@@AndreasSpiess This makes sense. It sounds like in ideal conditions the stove is probably fine for normal use, but anything less than ideal conditions will quickly cause problems. Thanks!
I liked the part where you said diesel generator with DC converter
Did I say this? That was a mistake!
Neat solution!
Did backup box price include technicans that you must call?
No. The work was separate. And it included the "prototyping". So, with the knowledge of this video, it probably would cost a third.
I have the same Huawei sun2000 system with 10 kw battery as you have, I asked my installer to add an additional backup box so I could use the system when the grid was down. He has never been back to install it and I'm beginning to think it's because he knows it's only capable of running a single power lead and I need it to power the whole house. Maybe all we need in addition to the backup box is this transfer switch ?
Just out of interest Huawei state the system should be able to run in off-grid mode without a backup box i.e if it's installed in a remote location without mains power, therefore is it not possible during a power cut to simply switch off the mains supply and switch the battery to DC ? will this not supply the power to the inverter and run the house? I have asked this question on various forums but never got an answer.
I would not buy a Huawei system for off grid (it will only provide one phase energy). There are much better solutions for that (e.g. Victron). The capabilities of the SUN2000 are well documented and I showed in a previous video why they cannot do 3 phase backup power (as many other simple inverters).
Do you have plans to include an MQTT message showing if and how many minutes you are on emergency power?
For the moment I do not have this intention. But I think, the inverter transfers its status automatically with all other data. So it is stored, but not used (for the moment).
Andreas, I am wondering if 3:13 KM3 in the backup box is wired correctly in this schematic. What is the purpose of having the coil from L1 to L2, and the contacts shorting L2 to N? And L3 remains floating? Second contact N to PE is clear to me.
All that seems a very special solution for a special problem, since the SUN2000 can deliver only 1 phase "Ersatzstrom".
This backup box is from Huawei and particularly made for the SUN2000 inverters. Other suppliers seem to sell their solutions. And hopefully, they integrate it one day into the inverter...
Only 4500 CHF for the battery? How did you get such a low price? Searching for LUNA2000 10kWh batteries usually shows almost double the price, which is why I usually don't find these systems worth it.
I explained the reason in my earlier videos. And I ordered last year, February, 24th.