Solar for whole house - which inverter ?

[willshakespeare]

Designing an off grid system abt 25kw - wanted advice on inverter capacity to power
I’ve attached pics of circuit board - 2 panels

- would the Solark 15k suffice for both ? Or I can’t connect 2 panels to one inverter ?

- other option is Solark 15k for the 3 ac’s and pool pump & Growatt 12k for the other panel

Thanks much

 

[42OhmsPA]

William, I suggest you partake in a lot more reading in the beginner section.
I don't mean to sound rude but it sounds like you don't have a complete grasp on this and I had to make a joke... Shakespeare and reading ?

Some feedback and lots of questions.
Either of those inverters could work, so could a Schneider or MidNite or Deye or MegaRevo or Voltronic.
Have you done a power audit?
25kw of what?
What is the most load you'll be running at any given time plus surge loads during this time?
Do you know the surge load of the AC compressors or are they mini split type?
Do you know what the pool pump draws? I assume it's 240v?
Are your loads balanced between the legs in your panels?
Is one panel a sub panel the other the main panel or is there a separate main panel feeding them? Maybe one is already a critical loaf panel?
Are you planning to DIY? Are you planning to sell back to the utility? Do you want battery backup?

That should be enough for now.
Oh pvwatts. gov and suncalc. org if your planning on solar panels.

 

[Hedges]

One more question ...

How thick is your wallet?

 

[willshakespeare]

Thanks guys
It’s going to be a hefty project
Have average use of 60-80kw/day

One panel is mainly a 220v panel with pool pump (using 1.5kw/hr), 2 x 50k btu ac & 1 30k btu ac, Tesla charger - so I’m assuming this one will have higher surge loads

House is new built so am not sure if the other one with gfci’s is sub panel or not.

Looking at 25kw pv array with Bluesun bifacial ground mounts, 4 Kong elite max and ? Inverter or inverters

Not an electrician that’s why was wondering if 2 panels can be connected to one big inverter - won’t be diying this - but planning to get supplies & have someone install & wire

 

[Hedges]

Before settling on a battery (or anything else), design the entire system.
BMS should talk closed-loop with inverter and charge controllers.
PV panels should make an array meeting MPPT voltage range, max voltage, max operating and short-circuit current.

For low-frequency transformer type inverters there are Schneider, Victron, some Outback, SMA, maybe others.
For high frequency, some Outback, SolArk, the brand new Midnight Rosie, maybe others.
There are also a number of low-cost brands many people have gone with.

Rosie isn't stackable yet but that should be coming.
SMA has a high-frequency hybrid coming, probably not powerful enough for your loads.

It is important to understand motor starting surge current and get inverters which can deliver that.

You're probably better off with a single system, and control to shed excessive loads.

 

[42OhmsPA]

Thanks guys
It’s going to be a hefty project
Have average use of 60-80kw/day

Yikes that's a lot of power but can see how it's possible. Note kwh vs kw... I generated 31 yesterday but struggled to use 14. (I don't have the electric dryer on solar / battery yet)

One panel is mainly a 220v panel with pool pump (using 1.5kw/hr), 2 x 50k btu ac & 1 30k btu ac, Tesla charger - so I’m assuming this one will have higher surge loads

Look into a soft start / hyper start for the AC units (I can't remember the exact name that's recommended here).
If you try and start the compressors without them I would definitely go with a Schneider 6848 Pro, maybe three.
Might want to consider running the pool pump direct from solar panels, there are controllers for this.

House is new built so am not sure if the other one with gfci’s is sub panel or not.

Did you get a wiring diagram during the build?

Looking at 25kw pv array with Bluesun bifacial ground mounts, 4 Kong elite max and ? Inverter or inverters

Make sure the max charge current of your batteries is not exceeded, you want to kepp them happy.
Look at current connected for rack batteries. I DIYd my packs but I'd likely go with CC for rack mount

Not an electrician that’s why was wondering if 2 panels can be connected to one big inverter - won’t be diying this - but planning to get supplies & have someone install & wire

They could or you could have one big ass battery bank feeding two inverters and the inverters feeding the panels separately. It depends how things are wired currently that decides what makes the most sense.
There is a resource section on here where you can post a work wanted add.
You'll likely not find may eager installers out there that want to install someone else's stuff they aren't familiar with...

 

[kromc5]

My usage goes up and down greatly but I have hit 80kw per day. When running the charger, heat up/down plus normal loads I have hit over 26+kw sustained. I would really think about your total loads that you might want to run at the same time to get a base for inverters. Since you stated off-grid you might want to see what I did and that barely gets me through the winter but your location could be far better.

 

[Hedges]

Make sure the max charge current of your batteries is not exceeded, you want to kepp them happy.

Half oriented SE, half SW would reduce peak current, extend hours.
You should also be able to program battery charge current, while allowing SCC to deliver extra current as needed by inverter. With the right equipment.

 

[willshakespeare]

Appreciate the valuable advice
Definitely soft starters for ac are a must
I was thinking if schneiders but was worried abt the 6k capacity, solark 15k had a higher mppt of 500voc so I can connect good 10 panels to each port
Might do a cheaper Growatt 12k for the lower surge load panel & Schneider for ac

Wiring etc in process - I ageee finding an installer is going to be a big problem - based in Dallas

 

[Danke]

Appreciate the valuable advice
Definitely soft starters for ac are a must
I was thinking if schneiders but was worried abt the 6k capacity, solark 15k had a higher mppt of 500voc so I can connect good 10 panels to each port
Might do a cheaper Growatt 12k for the lower surge load panel & Schneider for ac

Wiring etc in process - I ageee finding an installer is going to be a big problem - based in Dallas

15K:
MPPT 125V-425V
MAX 500V

Probably stay away from 500V is possible.

Which BlueSuns? They are probably a bit over 50V Voc.

Dallas can get down to 0°F?

That would be over 55V per panel.

 

[42OhmsPA]

The surge and overload capacity / duration of the Schneider is the golden ticket... You would pair the inverter(s) with high their voltage mppt, 600v.

 

[Hedges]

What I would use (of course)

3x Sunny Island, 3-phase 17kW continuous, 33kW surge
Up to 36kW of Sunny Boy, each with PV array sized 200% of inverter capacity, each MPPT input having 2 strings oriented SE & SW.
(You have to select PV panel Imp low enough to fit the MPPT max current.)

This works with 600V max input; mine are nominally 480Voc and 380Vmp.

 

[timselectric]

Ford F-150 Lighting.
All problems solved.

 

[Hedges]

Except one.

Ford suspends electric F-150 Lightning production for another week following battery fire

Ford is suspending production of its electric F-150 Lightning pickup for another week after a battery issue that resulted in one of the vehicles catching fire.

www.cnbc.com

 

[timselectric]

Except one.

Ford suspends electric F-150 Lightning production for another week following battery fire

Ford is suspending production of its electric F-150 Lightning pickup for another week after a battery issue that resulted in one of the vehicles catching fire.

www.cnbc.com

Wasn't that big of a deal. But the media was having a slow day. lol

 

[dougbert]

The surge and overload capacity / duration of the Schneider is the golden ticket... You would pair the inverter(s) with high their voltage mppt, 600v.

I have one Schneider XW Pro 6.8kw inverter ($3500 - then add in other components, yes) so I am admittedly bias

Schneider advertises the output of 6.8kw, which is the CONTINUOUS output power. It can handle 8.5kw for 30 MINUTES, 12kw for 1 MINUTE.
Other vendors advertise their peak output, not continuous

I plan on getting 2nd inverter in the future, 13.6 continuous, 14.4 kw for 30 minutes (due to internal 60 amp relays - go external relay transfer switch and it will handle 17kw for 30 minutes)

Here is a webinar on the XW Pro, at the time where he is discussing max load amounts with 1, 2, 3 and 4 inverters

It is hefty system. Great for turning pumps and so forth

watch the following for a comparison with Sol-Ark 8kw

To see my install of the XW Pro into my prior system link to https://diysolarforum.com/threads/s...to-xantrex-to-xw-pro-inverters.11/post-637210

It is a great off-grid inverter system as well as a hybrid grid system

 

[niktak11]

Dual sol-ark 15k with a few stacks of server rack batteries will handle the task

 

[willshakespeare]

Thank you all!