1kw Grid-tie (220v), 4kw pass through, with 48v battery?

[Frank in Thailand]

Google :
Can a grid-tie inverter be connected to batteries?

In an AC coupled system, the grid-tied inverter is paired to an off-grid inverter and battery bank. The off-grid inverter provides a second power source, which effectively tricks the grid-tied inverter into staying online. This allows you to charge your batteries and run essential appliances during a power outage

Ok, this is "old" .... Yes?
Already a smart company that made the combination??

Post in thread 'Grid tie solar with backup' https://diysolarforum.com/threads/grid-tie-solar-with-backup.62948/post-783764

AKA AC-Coupling.

Trouble is the way it's connected.
Grid tied gets the wave& voltage information from the grid, matches it, and increase the voltage a bit, so the power from the grid tied is used first.


It's easy, you can simply plug in the power socket, and it will provide electricity to that group of the house.



Absolutely easy, add on, additional power.

On/Off grid (or "hybrid") they don't "add". (AC - Coupling)
They sit in between.



All the grid power must go via that unit.

Makes sense and all, safety reasons.
But...

Say you want / have 1kw solar..
Plug in grid tied= 1 kw unit, 3 x 345w solar, done.
If your power group is able to provide 3500 watt, you get 1000 from the grid tied, and 2500 from the grid.

The on/off grid (& hybrid )
Still 1 kw.
Still 3 x 345w solar

Your power group is able to provide 3500 watt
You buy 1000 watt unit.

??‍?️?
Not going to work.
Well... You can use the 1000 watt.
But when you want to use the 3500...
Overload, error, beep, stop.

It sits in between, and logically, pushing 3500 watt through a 1000watt unit...
As default... Should not work.

2 possible solutions:
- buy the 3500 watt unit
- make it capable of both, yet limited to 1000W during blackout.

Victron calls it the pass through amperage.
Some other brands start to adapt this.

What grid tied units are out there that can be used as backup (so with 48v battery) and do provide roughly 3* their rated output as pass through amperage???

I do see several solutions, yet they all limit the passthrough to the rated capacity..

We really like to have 3-4 times the pass through capacity then the rating of the unit.
As usually.. just adding a bit and using a bit.

 

[FilterGuy]

Google :
Can a grid-tie inverter be connected to batteries?

In an AC coupled system, the grid-tied inverter is paired to an off-grid inverter and battery bank. The off-grid inverter provides a second power source, which effectively tricks the grid-tied inverter into staying online. This allows you to charge your batteries and run essential appliances during a power outage

Ok, this is "old" .... Yes?
Already a smart company that made the combination??

Trouble is the way it's connected.
Grid tied gets the wave& voltage information from the grid, matches it, and increase the voltage a bit, so the power from the grid tied is used first.

View attachment 158022
It's easy, you can simply plug in the power socket, and it will provide electricity to that group of the house.

View attachment 158023

Absolutely easy, add on, additional power.

On/Off grid (or "hybrid") they don't "add".
They sit in between.

View attachment 158024

All the grid power must go via that unit.

Makes sense and all, safety reasons.
But...

Say you want / have 1kw solar..
Plug in grid tied= 1 kw unit, 3 x 345w solar, done.
If your power group is able to provide 3500 watt, you get 1000 from the grid tied, and 2500 from the grid.

The on/off grid (& hybrid )
Still 1 kw.
Still 3 x 345w solar

Your power group is able to provide 3500 watt
You buy 1000 watt unit.

??‍?️?
Not going to work.
Well... You can use the 1000 watt.
But when you want to use the 3500...
Overload, error, beep, stop.

It sits in between, and logically, pushing 3500 watt through a 1000watt unit...
As default... Should not work.

2 possible solutions:
- buy the 3500 watt unit
- make it capable of both, yet limited to 1000W during blackout.

Victron calls it the pass through amperage.
Some other brands start to adapt this.

What grid tied units are out there that can be used as backup (so with 48v battery) and do provide roughly 3* their rated output as pass through amperage???

The EG4 18Kpv has a 12K inverter (50A) and can pass through 200A

 

[FilterGuy]

If you are in Thailand, the 18Kpv may be hard to come by. There are other hybrids with high pass-through.... but I am not familiar enough with the non-US market to recommend one. You might see if Deye makes one that meets your needs.

 

[Frank in Thailand]

Great!
But...

There isn't enough solar to make use of such a heavy setup.

My friend does have 3 phase.

Theoretical there is no objection to place 3 x grid tied , one on each phase.
Obviously, no load balancing between the phases, that's a drawback.

But...
That is (to my knowledge) all the drawback.

Each phase can have a spike of 10kw.
Usual power consumption is 3-4 kw.
120-150 kWh per day
50 kWh per phase.
Daytime 70%
35kw in 10 hours, 3.5 average where the peak is around noon, as the air conditioning units work the hardest

A 4kw grid tied will reduce most of his power costs.

Yet, he does like to have some backup option, if it's affordable.

He doesn't have enough solar yet to make a battery useful for the night.
3 sets of each 4500w solar.
They won't produce enough to cover his 120-150 kWh

 

[Frank in Thailand]

I made him a calculations based on his wishes...
He almost had a heart attack haha..
As he would need 60-70kw solar, and 70-80 kWh lithium. While that is cheap here 10kw for $1900...

Difference of adding or sitting in between is HUGE.

Grid is relatively stable.
One blackout per month 2-3 hours ( sometimes half a day) usually Daytime due maintenance.
The Thailand electricity poles are notorious and famous.


It does have frequent mishaps.

Yet... An petrol/ diesel generator is started quickly also if it's just for those power outs, and way, way more cost effective.

So first focus on cost reduction, and adding more solar.
When there is over production, it's time to think about battery.

But.. it's smart to buy the stuff that will be battery capable, for future use.

Or is this a stupid idea?
Working "modular"??

 

[ncsolarelectric]

There are lots of 3-phase grid-tied inverters, but most don't run on batteries. See Chint Power Systems, Sungrow, etc. for their commercial solar products. They should not be hard to come by in China.

 

[Cheap 4-life]

Gtil2 inverters are grid tie inverters that use batteries and do not need an offgrid inverter to do so. probably can’t use them for 3-phase. They can be used for single phase or split phase

 

[Frank in Thailand]

You are right, lots and lots of options for "the same thing", grid tied.

A few have a battery so they can feed when there is no solar power.

That base idea is childish simple: System doesn't care if the source is DC Solar or DC battery.
Downside.. high voltage battery.

Huawei has a few options.
Their batteries are at $4-5.000 per 5 kWh. (385v)
Not really attractive, as we can buy BYD 10 kWh for $1900 (48v)

They are still true grid tied inverter.
They "upped the voltage" so their power is used first and when not enough, the grid will doe the rest.

Yes... Same picture ?

I've been searching for several weeks now.
As soon as I see the word "hybrid" it's for 99.998% sure NOT grid tied.

Not adding, all power goes via the "hybrid"..
And this is not the solution he is looking for.

 

[Frank in Thailand]

Gtil2 inverters are grid tie inverters that use batteries and do not need an offgrid inverter to do so. probably can’t use them for 3-phase. They can be used for single phase or split phase

If you are talking about split phase....
We can't use in the rest of the world.
That is "USA only".

Thank you for thinking with me!

Edit.. I just googled, and going to watch a few video's

 

[Frank in Thailand]

I just read/ watched some information.
And they are great ?

They can be used 3 phase, and more then one unit on a phase.

Main downside: they can handle maximal 90v DC or in real life 2 panel strings in series.

2000 watt, 48v, 40A
For a battery not a problem 6 AWG or 16mm2

solar panels have 4mm2 cable / 12AWG. Rated for 20A, can be pushed to 30A but 40A will surely melt.

it is a great alterative.

Gried tied inverter, with a choice of batteries or solar as power source.

add additional MPPT to charge the battery, done ?

are there higher voltage stand alone MPPT available yet? (For a decent price)

The on/off grid inverters have 160-500v MPPT are roughly $550 and handle 4500-6000 watt of solar.

last time I checked ( about a year ago) hardly any, and those that could do 5-6000w solar on + 250v where double the price of an on/off grid unit.

 

[Frank in Thailand]

Just checked..

Victron has a nice one, solar input 90-450v output 5.5 and 11kw for 48v system. SmartSolar MPPT RS 450/100 (or 200) about $1200

The rest??
Lots and lots available at max 150-190v.
Price around $250 (and way lower)

Solar panels (325w) are wired now 7 in series. (2 parallel)
Knowing my friend, he prefers to pay some extra then to rewire the solar hahaha ??
7* 36v 252v. 4500w max.
(He as 3 sets like this)

Gtil2 inverters are a good alternative.
Price is OK.
Does what he wants, and can/ must do battery.

Yes, you can connect 2 solar panels in series (and some parallel) OR battery.

Not both at the same time.

That it has this option is already amazing flexible ??

 

[DIYrich]

Would this work:

SUN-29.9/30/35/40/50K-SG01HP3-EU-BM2/3/4 | 29.9-50kW | Three Phase | 2/3/4 MPPT | Hybrid Inverter | High Voltage Battery Inverter Company, Supplier | Deye Inverter Technology

NingBo Deye Inverter Technology Co.,Ltd is China SUN-29.9/30/35/40/50K-SG01HP3-EU-BM2/3/4 | 29.9-50kW | Three Phase | 2/3/4 MPPT | Hybrid Inverter | High Voltage Battery inverter company and supplier。 SUN-29.9/30/35/40/50K-SG01HP3-EU-BM2/3/4 is brand new three phase hybrid inverter with High...

www.deyeinverter.com

 

[Frank in Thailand]

Just visited him today, and made some calculations with him for the return on investment and what his option are with "just 12kw " solar. (42 panels)
(And 120-150 kWh use per day)

Yes, he might not use some of the maximal peak production.
But under 30kw solar, batteries don't make much sense.
When all in place he can schedule some "power hungry" stuff between 11 and 14hrs (laundry machine, pool filters that stuff)

Power outages that happen frequently, he better buys a 3 phase LPG generator. (And ATF)

So.. grid tied, no passthrough needed
Keep it as simple as possible.

Wholesale SUN-15/17K-G03 | 15-17KW | Three Phase | 2 MPPT Manufacturer & Supplier - Deye

Higher yields / Safe & Reliable / Smart / User-friendly The series products adopt 2 MPP trackers design. Equipped with screw crimp terminal for DC and AC

deye.com

This one looks good.
15kw is $1550 on first glance.

The Huawei 20kw Sun2000 KTL M5 is $1.750
Probably the 15kw is in the same price range as the Deye.

I have no experience with either software for monitor and registration.

I'm sure both are good.

Anyone has experience with either of the units?

Tomorrow I'll search YT to see if I can get some insight.

It would be helpful to get some insight.