Buying a Sol-Ark 12k tomorrow

[Hedges]

Trying to get an oscilloscope from my engineer for the next video on the sol-ark. Then we can do a couple of things - Probe the battery cables without ferrites, probe the output waveform, all sorts of stuff like that. I will see if they are willing to disclose that - I'm wondering if one is a different mix than the other to get different harmonics reduced, or if one ferrite just wasn't enough.

You can try just ferrites filtering what voltage is presented to scope probes.
But try it also driving a load, maybe resistive heater. Consider also a capacitor (but only if you have one rated for 250 VAC!)

Ferrites provide a series higher impedance at higher frequencies, an inductor. But doesn't take much current to drive voltage into your scope probe.
Addition of a low shunt impedance like a resistor, or better yet a capacitor (lower impedance at lower frequency) should knock down harmonics more.

 

[Fil-Am Gabe]

View attachment 27708

The box was actually a lot bigger than I was expecting. This barely fit in the trunk of my Honda Accord. I was like a kid in a candy store driving to go get this thing. The asking price was $6270 and after tax was $6800 or so

Ooohhhhh, I want one also. Congratulations

 

[Brandon8792]

Well... how does this compare to the growatt 12kw? I just couldn’t justify the price difference according to specs

 

[mrdavvv]

Well... how does this compare to the growatt 12kw? I just couldn’t justify the price difference according to specs

Can you link it?

 

[Brandon8792]

.

 

[mrdavvv]

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Seems like the Growatt its an offgrid inverter, not that good if you have net metering since it cannot backfeed to the grid.

Solark i think its 12K PV with 8K AC output, can work as an string inverter. Supposedly its around 10% more efficient (85 vs 95%), so that could offset a couple of panels in a big installation.

Growatt its 12K output with 8K PV. Its a low frequency transformer so that's good.

Growatt only supports 150V at PV, so you will need more copper cabling at your panels. Solark sits around 300 - 450V so you will have savings with less and thinner cable.

Thats what i can see with my unexperienced eyes, maybe someone else can help.

If you cannot spend that much, and are interested in solark, you can check the Deye / Sunsynk options, wich are almost the same according to other posters.

 

[Brandon8792]

Seems like the Growatt its an offgrid inverter, not that good if you have net metering since it cannot backfeed to the grid.

Solark i think its 12K PV with 8K AC output, can work as an string inverter. Supposedly its around 10% more efficient (85 vs 95%), so that could offset a couple of panels in a big installation.

Growatt its 12K output with 8K PV. Its a low frequency transformer so that's good.

Growatt only supports 150V at PV, so you will need more copper cabling at your panels. Solark sits around 300 - 450V so you will have savings with less and thinner cable.

Thats what i can see with my unexperienced eyes, maybe someone else can help.

If you cannot spend that much, and are interested in solark, you can check the Deye / Sunsynk options, wich are almost the same according to other posters.

the growatt inverter can do everything. Grid tie, off grid, generator start up, wifi monitoring etc. the solar efficiency of it is 98%.
I do see the pro of the higher voltage, could make the strings, but then you have the trade off if something goes wrong in that string then there goes that whole string... where with the growatt you could do a combiner box with 12 gauge wire, and then terminate with say 6 gauge wire. Maybe a max of 4 gauge if running farther runs. All in all you would have around $500-$800 more in wiring compared to solark. But the growatt is $2000 compared to the Solark

the 12k pv and 8k ac is alittle rough in my opinion. I know a typical stove will pull 12kw with everything on turned full blast. Coupling that with ac or dryer or anything, it makes it to where the solark would be out of the game.
I’ve found with my growatt 12kw, it seems the 7kw solar keeps the batteries up, while also generating enough power for throughout the day. So that’s a plus, but I do feel a few extra kw of solar input would be beneficial on it. Wish they would of made it 12kw, 12kw.

Don’t get my wrong I’m not dissing the solark, just trying to give comparison to comparison. I just don’t know if that would be worth the difference in cost from what I’m seeing.
The growatt inverter/charger I’ve had has been extremely reliable, and the sucker weights a good 180+ lbs. the copper transformers inside are beautiful

attached is a picture of the inside of a 6kw... I didn’t want to tear my 12kw open

 

[mrdavvv]

the growatt inverter can do everything. Grid tie, off grid, generator start up, wifi monitoring etc. the solar efficiency of it is 98%.
I do see the pro of the higher voltage, could make the strings, but then you have the trade off if something goes wrong in that string then there goes that whole string... where with the growatt you could do a combiner box with 12 gauge wire, and then terminate with say 6 gauge wire. Maybe a max of 4 gauge if running farther runs. All in all you would have around $500-$800 more in wiring compared to solark. But the growatt is $2000 compared to the Solark

the 12k pv and 8k ac is alittle rough in my opinion. I know a typical stove will pull 12kw with everything on turned full blast. Coupling that with ac or dryer or anything, it makes it to where the solark would be out of the game.
I’ve found with my growatt 12kw, it seems the 7kw solar keeps the batteries up, while also generating enough power for throughout the day. So that’s a plus, but I do feel a few extra kw of solar input would be beneficial on it. Wish they would of made it 12kw, 12kw.

Don’t get my wrong I’m not dissing the solark, just trying to give comparison to comparison. I just don’t know if that would be worth the difference in cost from what I’m seeing.
The growatt inverter/charger I’ve had has been extremely reliable, and the sucker weights a good 180+ lbs. the copper transformers inside are beautiful

attached is a picture of the inside of a 6kw... I didn’t want to tear my 12kw open

Sorry dont want to contradict, dont even know the inverter, but are sure you can backfeed to the grid?, i dont see any reference in the site. It has UL1741?

About the efficiency, i have this doubt from a long time since i have similar inverters (MPP Solar's). Isnt PV input converted to battery level voltage, and then to 120 / 240V trough the inverter?. in that case wouldn't the efficiency drop to said 85%?

String inverters can of course do more direct conversions of PV to AC, with >98% efficiency, but not sure if those numbers are ok with our DC coupled systems.

 

[Brandon8792]

Sorry dont want to contradict, dont even know the inverter, but are sure you can backfeed to the grid?, i dont see any reference in the site. It has UL1741?

About the efficiency, i have this doubt from a long time since i have similar inverters (MPP Solar's). Isnt PV input converted to battery level voltage, and then to 120 / 240V trough the inverter?. in that case wouldn't the efficiency drop to said 85%?

String inverters can of course do more direct conversions of PV to AC, with >98% efficiency, but not sure if those numbers are ok with our DC coupled systems.

I’m not 100% sure if it can back feed but I do know it can operate with the grid system no problem. Most companies in our area only offer to zero out your bill

it may be around 85%... I was speaking for the solar charger. I havnt attempted to calculate the ac conversion

 

[HighTechLab]

check the Deye

For reference, I looked into this for a while prior to buying the sol-ark. They will not send stuff to the USA because of their contracts with Sol-ark. If you ask for any technical documentation, they immediately say to go to sol-ark. I even tried using on of my vendors in China to buy them from Deye and then send to me and that route was not feasible.

_____________________________________

Update on my system - So as of yesterday, I'm finally up and running 100% how I would like. Some of the things to work through were the fact that in our off-grid setup, we have some unique systems that take advantage of power, when available. With the addition of the sol-ark, "Generator Peak Shaving" or also known as "Gen Support" on other systems, is a critical selling point for us due to the nature of our system and loads.

Essentially, we are spoiled and have a hot tub. When the generator is running, we have 9kw of power going to the sol-ark, and another 4kw of power going directly to the heating elements on the hot tub. In our previous configuration, all of the power consumed was via a 48vdc inverter and all battery charging was via a similar inverter/charger that only acted as a battery charger. This meant that if any loads on the property turned on, the batteries would buffer the difference, at the cost of ac-dc-ac conversion. The spa was transferred to the generator when it was running.

With the sol-ark, our loads now pass through to the generator. This means with our 13kw of known load from battery charging and spa heat now has additional potential load on top of it. Not good to avoid tripped breakers.


The programming of the sol-ark is very difficult for our strange situation. Essentially I set the sol-ark into "Power limited to Home" with the generator connected to the "GRID" input. Essentially the sol-ark is grid tied to the generator now, with the exception that the CTs will limit power from going backward into the generator. Now our generator panel has 14kw of power available for consumption, and if demand requires, can have an additional 8kw of power fed in from the sol-ark. Things like spa heating elements and electric clothes dryers can be fed on this panel so they only are able to be ran with the generator already running.

 

[mrdavvv]

For reference, I looked into this for a while prior to buying the sol-ark. They will not send stuff to the USA because of their contracts with Sol-ark. If you ask for any technical documentation, they immediately say to go to sol-ark. I even tried using on of my vendors in China to buy them from Deye and then send to me and that route was not feasible.

Yeah some other people mentioned this in another thread.... but they seem to be able to purchase them (Not verified), the Chinese just told them not to say where they get them... jeje

I find it good that the Chinese honor their contract with Sol-Ark for the most part.

Some other people might check with those more flexible chinese vendors, or with sunsynk in HonKong.

 

[Hedges]

Things like spa heating elements and electric clothes dryers can be fed on this panel so they only are able to be ran with the generator already running.

If you wire a 240V heating element to 120V, it will consume 1/4 the power.
You could arrange to enable them when battery is near full or better when PV production is being curtailed.
What I would like, for a frequency-shift system, is a dimmer circuit with servo (PID) circuit to maintain a target frequency, or ramping up from 0% at 60.5 Hz to 100% at 61 Hz.

So long as the dimmer's chopping of AC doesn't upset the inverter; a 1.0 power factor switching circuit with filtered input would be better. I think VFD upset my transformerless inverter so changing to transformer type.

 

[ArthurEld]

I am hoping to use the Smart load option instead of the generator connection or ac coupling. I'm sure it will take me a long time to get all of that stuff working.

 

[Hedges]

I get many search engine hits on "Smart Load"
Have a link to the product or feature you're referring to?

I'm not immediately finding commercial products for frequency shift load control, but here's an article on doing it with Arduino.

Discretionary Load Control on an Off the Grid Power System Using PfodApp™

Discretionary Load Control on an Off the Grid Power System Using PfodApp™: Background One of the pfodApp users lives off the electricity grid on a small rural property. This instructable describes how he used pfodApp and Frequency Shift Power Control to automatically turn discretionary loads on...

www.instructables.com

 

[ArthurEld]

This from the SolArk manual

Smart Load (Gen Load)
▪ This mode utilizes the Gen input connection as an output which only receives power when the battery is above a user programmable threshold.
▪ The Gen input breaker in the user area of the system becomes an output to high power loads such as a water heater, irrigation pump, ac unit, pool pump.
▪ Smart Load OFF Batt
• Battery voltage at which the Gen load will stop being powered
▪ Smart Load ON Batt
• Battery voltage at which the gen load will start being powered
▪ Note: Gen Load is limited to 40A at 240V (Do not exceed!)
• Solar Watts is for on grid.
o System waits to turn on smart load until enough PV power is produced (when on grid)

 

[Hedges]

OK, Smart Load uses one of two relays on AC input of SolArk.
SolArk has one relay for grid power, another for generator input.
Off grid, the suggest connecting generator to grid input.
"Smart Load" means "generator" relay gets closed at some (higher) battery voltage, opened at some lower voltage.
A load on that circuit gets power when there is relatively full battery.

In Sunny Island, only one input for either generator or grid, requires external transfer switch if both are to be used.
No power relay built in for "smart load", but two signaling relays are available which can control external power relays.
These are referred to as "load shed" rather than "smart load", but same function (based on calculated state of charge, not simply voltage)
For something like A/C, the relay could just close the control circuit. I plan to do that, also a power relay on one hot leg of the clothes dryer (leaving time and motor running.)

SMA used to offer 6kW "smart load for sunny island" which delivers variable DC for heating elements to make use of AC power which would otherwise be curtailed. It would run only on excess power, not cycle battery at all. That could go to a water heater element, but I would wire the water heater's thermostat and over-temperature cutout to AC side of "Smart Load", not DC side.

https://files.sma.de/downloads/SL6000-DEN102310.pdf

 

[ArthurEld]

Wow that's a great catch Hedges. I didn't realize you could use Generator and Smart Loads at the same time off grid.

I figured a switch could be used if you needed both on grid.

And from what we discussed in the past, I think you said that micro inverters don't need to be AC coupled. They can go right to the main panel.

Load shed, I'll remember that

 

[Hedges]

And from what we discussed in the past, I think you said that micro inverters don't need to be AC coupled. They can go right to the main panel.

That's if you only want the micro inverters for grid tie net metering, but not available while off-grid.

I think one SolArk was 8kW inverter, 12kW pass through. So putting 4kW of AC coupled grid tie inverters on it would be ideal.

With my Sunny Island, pass through is limited to 6.7 kW per inverter/relay. But off grid, 12 kW of AC coupled inverter can be managed per Sunny Island. So 12 kW battery inverter and 24 kW of PV inverter is reasonable, (2x SI, 4x SB), or 2 times that. Or 18 kW battery, 36 kW PV for 3-phase.

I see that Victron supports 6 inverters on each 120V phase, 12 for 120/240V, 18 for 120/208Y 3-phase.

 

[ArthurEld]

I didn't realize the micro inverters wouldn't be available when the grid was down.
I just don't want to give up the load shedding so that I can have AC coupling.

 

[Hedges]

AC coupled inverters on output of SolArk would add to AC power available while off grid. I don't know how they are managed by SolArk. The manual mentions them, but says,

"If you have AC coupled solar panels and a generator then you must use the TOU setting to prevent the generator from being called for during the daytime or else damage will occur. Simply uncheck the “charge” checkbox for time slots that may have PV production. v. If Off-Grid, connect the generator output to the “Grid” input in the Sol-Ark and select"

"Max AC Coupled Input (Micro/String Inverters) 9,600W / 9,600W"

The systems I'm familiar with raise frequency above 60 Hz to signal "Too much!" and the AC coupled inverters respond by either linearly reducing output or simply shutting off.