Connecting Photovoltaic Panels via 15KW 3-Phase UPS: Experiences & Practical Advice Needed

Hello, dear group.
I would like to find out from practitioners what the matter of connecting photovoltaics through ups looks like.
I have two 3-phase UPSs with a power of 15 KW (but a separate case for them). I would like UPSs with batteries to act as an energy buffer when the solar panels are not working. I just walk away from being addicted to Energetyka as much as possible. What are your experiences on this topic. Does it work?
I am also aware that a complete departure from energy is impossible.
Currently, I have a power allocation of 1F 5.5 kW and it is enough for me, but the UPSs are in working order and are decommissioned, they are 15 years old, but I will buy them (even cars from Angola). I found panels with an inverter for 6 KW for 7,000. I have a place.

Anyone working on this topic?

Perhaps I will start with a cursory description of my system. It is a substitute for what you are planning. It contains a battery with a capacity of approximately 1200Ah and a voltage of 27V. There is no central UPS but a few smaller converters. Two with a power of 1500 / 3000W sine, and probably 3 smaller ones of the ups. All sinusoidal. They support most devices with low energy consumption. Fridge, freezer, circulation pumps, several monitors and several computers, 2 laptops. Most of the lighting in the house is powered directly by 27V DC.

The entire system is powered by one large switch mode power supply set at 26.5V and a PV DC converter. It gives 27V output, which means that when the sun is shining, the switching power supply smoothly stops charging. The total power of 3kW panels - is a purely theoretical power. They are never able to give so much even with max sun and low temperature. Not fully charged batteries guarantee their longer life. It is worth considering that they should be in a cool place. It also extends their lives. Converter between panels and battery. it is powered from 54V. This is roughly a power point for cold panels. 48V for hot. We are talking about typical 24V cells connected by two in series.

For your system, you will need to develop a similar device suited to the battery voltage of your UPS. Charging from the UPS itself must be set so that it gives a correspondingly lower voltage.

The most expensive ones will be, of course, depending on how long they are supposed to last. For me, it is about 2 days without sun and electricity. I was able to buy for 1.4x PLN battery, perfect condition, gel.

In my opinion, 3-phase UPSs are rather useless for powering the home. It is about the inability to ensure even phase loading and this is what such ups expect.

Car batteries have an extremely short life and I strongly advise you not to use them unless they are almost free and you will have to replace them every 2 years.

Storing 1kWh in batteries costs several times more than purchasing 1kWh from Energetyka. But free energy costs money!
Undercharging the batteries does not extend their life - just like deep discharges.

On the other hand, even a slight overload significantly shortens the service life. Therefore, I do not come close to the limit when the electrolyte begins to break down. The cost of storing this energy has absolutely nothing to do with it. It's about the reliability, independence and energy security of my home. Professional power engineering does not guarantee these things.

I didn't mention free or anything.

Of course, you can go in a different direction and connect an inverter to give electricity to the grid and earn money on it. It will probably come out much cheaper. The cost of inverters is relatively low. It only remains to get things done in the ZE.

This solution is irritating because if there is no electricity in the network, it is not, despite the fact that the sun is shining and there are possibilities. Such situations are commonplace in the US after hurricanes, for example. And in our country as well. Switch-offs lasting up to 2 days are nothing new to me.


Speaking of completely abandoning dependence on professional energy, I will say that as of today I do not have enough self-denial, but the thing is possible and I even have such friends. They have a house only with solar, wind and aggregate. They went with a very modest battery capacity. As far as I remember, it was about 200Ah / 24V. Unfortunately, I can't do that. I'm more addicted to technique

You see, and I thought that the solar system would just go to the home network straight through ups. Why do I think about the ups guarding the battery status. From the inverter, I will connect to the cruising ups and then to the receivers. The only thing I would have to do is disconnect from the power industry. Anyway, that's what I have on the aggregate. Batteries are not a problem. I have them cheaply from cars from England, but I am wondering about traction batteries that are used in forklifts. I also have access to such.

The thing is, when you connect the photovoltaic to a UPS, it won't do anything about it. The batteries will simply be charged straight from the cells without any control. The traction Aku is much better.

The UPS will not run on DC from the panels.

Okay, but I say that the panels for the inverter and the inverter - (regulator, converter)
to the ups and the ups only for pickup.

Here you go.