[Solved] On-Grid Photovoltaic Installation with UPS, Three-Phase Power Generator & ATS: Pros & Cons

Hello,

I wanted a broader opinion.
Well, I'm talking about the configuration where the on-grid photovoltaic installation will be made.
It will be made with funding from the commune, so I don't really have control over everything. However, I would like to be aware of the limitations resulting from the proposed solution, which is expected to appear in the spring.

The thing is that there were intermittent power outages in the area where I live. Usually lasting no more than a second, but everything was resetting. The power plant was warned and the blackouts disappeared, but this is not the first time they appear.
In addition, there are temporary outages because the network in the area is being modernized.

I would like to protect myself against long shutdowns and use a three-phase power generator with ats and AVR stabilization. Three-phase because, unfortunately, I have devices after all phases and it's hard to convert now so that the critical ones are on one phase.
In addition, I have an induction hob that needs 3 phases where with longer shutdowns I would like to use one "burner".
So I estimate that I would need about 10kW of a three-phase generator.
And here is the problem because when I was looking for aggregates with such power, they are for 5k and for 15k where the description does not show too much what the differences are. Everyone says it's great and all.
Could I ask for help in identifying a worthy investment and verifying whether my assumptions are correct. I mean, is it worth pushing into a generator with such power.
The second thing about the photovoltaics that will be. When there is no electricity in the grid, the photovoltaic does not produce anything, but when power from the generator appears, production will start. If the load is too small, there should be some communication between the photovoltaic and the generator?
Or maybe the inverter is supposed to detect the lack of consumption and turn off the photovoltaic system? If so, will every inverter be able to do this or does it have to be dedicated?

If in the future I would like to expand such a set with a UPS, does it make sense. To make it 3-phase, for example:
"UPS EMERGENCY POWER SUPPLY POWER WALKER VFI 10000 CPE 3/3 BI"
However, there must also be communication with the ATS here. Connecting the UPS to each critical device as soon as the power supply from the generator will be available in a few seconds does not make sense.

I would like to add that such a solution will certainly be expensive, so before I start digging further, I am asking for advice and opinions.

You need to use ATS and in my opinion the photovoltaics must be connected to the network under the contactor from the network side, when the ATS supplies the building with the photovoltaic aggregate, the photovoltaic does not see the grid voltage and will not start and you drive only on the aggregate. Somebody correct me if I'm wrong.

krisskos wrote:

The second thing about the photovoltaics that will be. When there is no electricity in the grid, the photovoltaic does not produce anything, but when power from the generator appears, production will start.

It always produces.
But ... the sun must shine well for it to produce a lot.

Photovoltaic is to produce energy for free.
10 kW from photovoltaics - that's a huge number of panels.

Change the power distribution and limit the backup power to the necessary.
The induction hob uses 2 phases, not 3 phases.
It will also work on one phase.

I was imprecise. Photovoltaic is to be used only to produce electricity and reduce electricity bills. Since the commune provides a large subsidy, this is a solution that it wants to use. It will not do here as a source of energy because it is unreliable. Besides, it will be around 4-4.5 kW. If you get a cloudy day, this energy will not be too much, not to mention how the failure will be in the evening. I mean the fact that it exists and how to make a UPS-generator system.

As for the album, I'm not so sure if it will go on 2 phases. Once one phase failed and the board flashed errors until phase 3 came back. And it didn't help right away either because I had to "restart" it as there were 3 phases, i.e. turn off the fuses for 3 phases going to the board at once and turn it on.

As for the power reduction for the backup power system, it will not be that easy. As it turned out, the cables were quite accidentally distributed, but maybe we could go down to some 5-6 kW.
Only I don't see any UPS with this power for 3 phases. The least I found was 10kW.

I am asking for your opinions and help.

As I wrote earlier about the panels and then you will have them off your head, depending on what you want to power from ups, it should be connected right after ats and then circuits protected by ups because I suspect that you cannot make a separate switchgear with circuits protected with ups. For this, a bypass can be used, in the event of a UPS failure, the power supply can be quickly bypassed.

The backup power supply is selected according to the power of the necessary devices, if according to you this necessary power is 5-6kW, then the generator is approx. it's probably also 15-20 with additional batteries because they are usually selected for about 10 minutes. support. Then such a UPS constantly supplies the selected circuit and in the absence of the mains the genset starts up.
Such a reserve set costs tens of thousands and will not make the PV grid work. But as necessary

For it to be relatively cheap, it would have to run on one phase
I have this at home:
- PV 4.6kW (5.8kWp) 1F
- I switched 90% of the receivers to the same phase as PV
- emergency power supply 1000W Volt Polska (Chinese) 1F and 42Ah battery (about PLN 560 + battery)
- Chinese aggregate, which I left after building a house 5.5kW 1F (PLN 1800) - I recommend it because it still works
- 4-field induction hob, which can be connected in 3 different ways - I just have 2 phases connected - two cooking zones on each phase. The largest and medium fields (I use 99% of the time) are on the phase where I have PV and the smallest and second average on a separate phase (I use it very rarely). When one phase failed, only half of the fields did not work for me. Therefore, check if you have another connection option. I don't think you need to connect 3 phases at once - unless you have situations where you heat on 4 fields at once (power), which I doubt.
During a few-hour power failure - I power the most important things from the 1000W converter; mechanical ventilation from the river, sewage treatment plants, entrance gate, lighting (LED everywhere), TV, pump in the air intake and other small devices. And that helps. I have another 65Ah battery from the car just in case. If I want to cook dinner at this time, I start the generator and then I can easily power 2 fields on my induction hob. I haven't had to start the generator yet because the break was never long enough and besides, such a generator consumes 2.5 liters of gasoline per hour. But I admit that I have frequent power outages and I'm thinking about 2 additional PV installations, but a hybrid one. Or I'm thinking about ordinary PV and a 2000W inverter, because sometimes 2 pumps are turned on at once (treatment plant and intake)
Simultaneity is the key.
P.S. To complicate the topic: I have everything on electricity, including CO and DHW

Thank you for the information. I would like to achieve something similar.
I haven't been able to determine what about the album yet because it's a key issue for me. I will certainly not cook on 4 fields at once during a breakdown, but if there is no electricity, you have to pull out the gas burners and install cylinders. It's a bit embarrassing.
I don't have gas in the area because the permits to break through the provincial road are dragging on. On the other hand, I don't know if I want to pack gas.
I have an eco-pea coal boiler room, but with the current trends in coal prices and the anti-smog law, I will have to change to gas or a heat pump.

I have a few questions about your solution:
- What if you don't have electricity? how do you have PV connected because it can't give electricity to the grid as, for example, there is no one at home and there is no consumption?
- I assume that you have disconnection of the grid somehow arranged in the event of a power outage, but what if you are not there and the PV produces and there is no energy collection on a beautiful sunny day? No problem? Will it turn itself off or what?
- I personally heat the DHW in the summer with the air PC and it works very well. In winter, however, the water is heated by the stove and the PC only acts as a tank. What air or ground PC do you have? How does it work if you can share? I will add that I have mixed heating, part on the floor, part on the radiators. do you have the same or just the undershirt?
- as for the generator, I understand that you fire it manually? You don't have any ATS?

@ Krisskos
- when there is no electricity in the grid, no on-grid inverter (approved for installation by the operator) produces AC electricity. They won't let you install anything else. (another topic is hybrid inverters)
-CWU - 200l boiler, 2kW heater all year round
-I have the unit in a shed 50m from the house and during blackouts I just don't want to drag it around or unwind the cable to boil water for tea, firing with a string is not a problem. As a curiosity, I will add that I converted it to gas. I bought a set (carburetor) on Ali for about $ 38.
Power outages are frequent but short - mostly 1 second flashes. Recently, it was a bit longer, as much as 4.5 hours, and in addition, when I call the Tauron hotline, I know when the failure is planned to be removed. So I knew that a 42Ah battery would be enough for me (without cooking). It is a bit annoying when the weather is nice outside, the roof is covered with panels and there is no electricity in the socket. A neighbor told me that a few years ago, during the winter, there was no electricity for 5 days, so I keep a generator for such occasions.
Answer the question of whether you have frequent and long-term failures and then calculate whether it pays off to push for expensive backups. I propose to consider various scenarios and what you are able to give up then and what is necessary to survive - be like preppers
I just gave up the idea for a hybrid inverter for my second, smaller, planned installation because the surcharge would be about PLN 1200 (Chinese) - 4000 (Hybrid Fronius). Not profitable.

here's something about my house and electricity consumption
https://www.elektroda.pl/rtvforum/viewtopic.php?p=17702101#17702101

Added after 33 [minutes]:

krisskos wrote:

I don't have gas in the area because the permits to break through the provincial road are dragging on. On the other hand, I don't know if I want to pack gas.
I have an eco-pea coal boiler room, but with the current trends in coal prices and the anti-smog law, I will have to change to gas or a heat pump.

Regarding this topic: if you go in PV, it will be profitable to have a pump or air conditioners in the rooms (also pumps, but small ones). In my opinion, thermomodernization is the most profitable, especially since reliefs have started (for PV and pumps too)

@Brunoxp
I've read it and it's interesting there. Unfortunately, I wasn't that aware of everything right away and now I'm wondering what else can be learned.
So I'll take the topic.
As for UPS, do you have UPS online or not?
Can you tell why you have oversized PV installations?
As for the installation for me, as I read, I will have to have 3F when installing 4-5kW.

As for the UPS, it is not so easy for me to switch to 1F because you have to switch practically the whole house. The installation was done in such a way that I have several rooms on one circuit and, what's worse, sockets and lights. I can't just reconnect the lights to the UPS. This is a big problem because in the event of a power failure, there could be several devices at the same time.
Let's say an oven or a washing machine can be separated, but no TV sets because there will be no light in part of the house.
Simultaneity can hurt.
As for the dropouts, those 1s that come and go hurt me the most.
So for me, the generator would be recommended with ATS because the UPS would support these 30-50s, and then the generator would start.
How do you have PV when it comes to powering the inverter. When the current disappears, then the UPS maintains a different phase than the inverter is connected?
Does he deduce well?

I have the WHIRLPOOL ACM 877 NE IXL board and from what I can see it could be connected in such a way that, despite one phase, some of the fields would heat up during major power failures and a working generator. I'm no expert here, though, so if anyone can confirm, I'd appreciate your opinion.

@theo33
And as for your thread here, assuming that he decides on a UPS set and a 3F generator, could you recommend something for such power?
I found a few companies but how the equipment works in reality is another matter.

krisskos wrote:

As for UPS, do you have UPS online or not?
Can you tell why you have oversized PV installations?
As for the installation for me, as I read, I will have to have 3F when installing 4-5kW.

UPS online Volt 1000W Pure sine on a separate separate circuit (+ extension cords), i.e. it does not supply power to any phase during a blackout.
Pushing the current to the phase where the inverter is is a separate topic, which I have given up for now. https://www.elektroda.pl/rtvforum/topic3543022.html
Generally, oversizing the generator (panels) in relation to the inverter is strongly recommended https://www.fiff.pl/moc-instalacji-pv-a-moc-falownikow-fronius/ - in my geographic latitude at least +12%(Szymanski).
The story of my oversized (PV):
I was supposed to have a 5kW inverter and a 5.77kW generator on the roof - an oversizing of about 15% - perfect.
I ordered a 5kW 1F inverter, unfortunately it did not pass because it turned out that Tauron allows you to let in a maximum of 4.6kW on 1F (while probably PGE or Enea allows 5.6kW)
The inverter went to the manufacturer/representative for reprogramming and limiting the power to 4.6 kW - the number of panels on the roof remained unchanged because I assumed the expansion of the installation in the future.
So at the moment I have a 4.6kW inverter and a 5.77kW generator - oversizing by about 25% and the manufacturer's assurance that the warranty will be ok (I know - I can put this assurance
The total electricity production for the exceptionally sunny 2018 was 6.45MWh, which is 112% of the theoretical annual production. With a 5kW inverter I would have a better result. The question is by how much, I don't know. Fronius says that oversizing by 18% gives a loss of annual yield of up to 0.5%, let's assume that with my oversizing there will be a loss of 1%, i.e. the entire 64kWh per year. https://www.fiff.pl/uzyski-energii-dla-roznych-ukladow-modulow-i-konfiguracji-falownikow/
I lost something on production but I gained something on balancing - I didn't count it.
Now, after a year of living, I know what my electricity consumption is and that's why I add a 2.4kW generator to the roof (it won't fit any more) and another 3kW 1F inverter to another phase. After switching 3 panels from the old installation to the new one, it will be 3.3kW to 3kW, i.e. 10% oversizing (almost perfect) and in the old one the oversizing will drop to about 8%

Added after 3 [hours] 38 [minutes]:

krisskos wrote:

Simultaneity can hurt.

Believe me, it didn't hurt me for a year: I didn't blow fuses or pre-meter protections (25A) even once, and I have a considerable annual electricity consumption (7.85MWh).
Yes, I do not have flow water heaters or 3F engines.
Honestly, I don't know why I ordered a 16kW 3F connection (because everyone does it?) Since 6kW from one phase does the trick. Certainly no small merit in this PV installation.

During the last storms on March 11, the entire town was without electricity for about 24 hours and my electrical installation 1F + 1F aggregate passed a combat test.
After a few hours, I plugged the generator into the WLZ instead of a separate separate line because it was troublesome to play with extension cords. Of course, I had previously disabled the protections from the ZE and PV inverter (I did not dare to experiment with aggregate + PV on-grid, maybe someday).
I admit that the 5.5kW generator gave advice for 24 hours: the house was lit, you could cook on 2 out of 4 induction burners, you could heat with air conditioning, but there was no need because it was warm inside. At the same time, I gave electricity to my neighbor (their generator did not start them) so that she could power the circulation pumps of the radiators and somehow normally exist.
Less than 4 cylinders x 11 kg of gas went - that is, the cost is

@Brunoxp

You provided very interesting information.
However, I am curious about one thing. Why didn't you try photovoltaics and a generator? What are you afraid of?
I have only a light theoretical basis, so I would like to seek the opinion of people with more knowledge in this topic, who can also apply it in practice.

krisskos wrote:

However, I am curious about one thing. Why didn't you try photovoltaics and a generator? What are you afraid of?

I'm just afraid of the inverter boom, which cost about PLN 5k

Such an inverter for PLN 5k certainly has a lot of protection and if he does not like the current from the generator, it will not synchronize with it and will not work.

batot wrote:

Such an inverter for PLN 5k definitely has a lot of protections and if he does not like the current from the generator, it will not synchronize with it and will not work.

you're letting me test it
I really would like to test this option but I need to be 100% sure that nothing will happen.
Or in other words: can someone tell me the name of the device (inverter, UPS, whatever) that will generate electricity with very good parameters, such as from the grid, so that the inverter will synchronize?

Brunoxp wrote:

good parameters

A company UPS can handle APC, etc. But what to do with the surplus energy because there is nowhere to give it away, although I can limit production in the range of 0-100% in my Delta ...

Yes, the conversion is just replacing the carburetor.

Great idea, can you give some details? Which generator model, which conversion kit?

Regarding the cooperation of PV and the aggregate - it is possible and sensible, all you need to do is install an energy meter on the power supply of the house
connected to the inverter via a modbus link or another dedicated for a given manufacturer. You must select the option blocking the outflow of energy to the grid.
Then the generator will be treated as an external network (it will provide voltage and frequency) and the photo inverter will provide power to the cottage.
As the demand for power decreases, the inverter will reduce production in real time. Of course, when the sun goes down or there will be more consumption
the generator needs gas.

Lisciasty wrote:

Regarding the cooperation of PV and the generator - it is possible and sensible, all you need to do is install an energy meter on the power supply to the house
connected to the inverter via a modbus link or another dedicated for a given manufacturer. You must select the option blocking the outflow of energy to the grid.
Then the generator will be treated as an external network (it will provide voltage and frequency) and the photo inverter will provide power to the cottage.
As the demand for power decreases, the inverter will reduce production in real time. Of course, when the sun goes down or there will be more consumption
the generator needs gas.

This is some light at the end of the tunnel. Before, I didn't know how to bite the subject without going into hybrids and batteries, now I know what to look for. On the Fronius forum, they tell you how to do it and on what components. Thanks Leafy.

Regarding the aggregate, I will paste the answer I sent to users on priv.
Single-phase generator - Chinese 5.5kW (5.0kW) with AVR, protection 22A - typical clone of the Honda GX390 engine, 188 cm3 and 13 HP which are full in the markets. In the Internet of Chinese or original Honda spare parts, there are a lot of them. Mine is fired with a jerk (or a large drill) but I recommend buying versions with a starter for convenience or automatic start.
When it comes to a propane-butane carburetor, check out Aliexpress or Amazon: search for the phrase "gx390 propane conversion kit" - there are also videos on YT on how it works. Price from $28
https://pl.aliexpress.com/wholesale?catId=0&initiative_id=SB_20200109040014&SearchText=gx390+propane

If you were buying a different (smaller/larger) Chinese unit, you need to find the name of the Honda equivalent (comparing capacity and power), on which the Chinese based how they copied the design, and then look for the appropriate kit to convert to propane.

PS I used to see these kits for my aggregate on Allegro, but recently there are no.
PS2 Apparently, the Americans connect such converted aggregates to the gas network, but I do not encourage anything
https://www.youtube.com/watch?v=nO839Sayci0

I resigned from the aggregate and I will install only the PV. I will wait for the prices of energy storage to drop as it happened with PV.