List of AC RETROFIT capable inverters

[1201]

many hybrids can ac couple, but what if the grid is stable and one doesn't necessarily want to go through the trouble of ac coupling, but still wants to use excess energy from the grid tied inverter to charge a battery?
With an ac retrofit solution the hybrid inverter can measure any power flowing back to the grid from any external sources, and divert that power to its battery for use later, so you just leave the grid tie inverter connected exactly as it always was.

please post if you know any inverters that can do this. I will update the list as more submissions come in

Inverters that can:

• Victron inverters, via ESS
• Solis hybrids , confirmed by @SeaGal
• Goodwe BH series high voltage inverters
• Sungrow Sh5.0/10rt
• SMA Sunny Boy STORAGE
• Tesla powerwall
• Enphase IQ battery 5P

Inverters that cannot:

• eg4 18kpv , confirmed by @Coopy
• Solark 15k, per solark ac coupling guide

 

[SeaGal]

what if the grid is stable and one doesn't necessarily want to go through the trouble of ac coupling, but still wants to use excess energy from the grid tied inverter to charge a battery?

Just for clarification; in my mind, the "ac-retrofit" mode you are referring to is what I would call "ac coupled". I suspect what you are calling "ac coupled" is what I'd call an AC mini or micro-grid (i.e. a dedicated AC feed like from a generator).

But... hey ho, you call autumn, 'fall' and call petrol, 'gas'

 

[Luk88]

I guess the intent is to get a list of inverters that can do it "out of the box" not those you can "force" into doing it by getting a smart meter and programming/scripting a DIY solution to detect when we're exporting and if so charge from the grid at the amount limited by the export current.

 

[1201]

Just for clarification; in my mind, the "ac-retrofit" mode you are referring to is what I would call "ac coupled". I suspect what you are calling "ac coupled" is what I'd call an AC mini or micro-grid (i.e. a dedicated AC feed like from a generator).

But... hey ho, you call autumn, 'fall' and call petrol, 'gas'

I dont even know what a mini or micro grid is lol.

With ac couple the grid tie inverter is connected to the output of the hybrid inverter and the hybrid inverter provides the ac reference (grid signal) for the grid tie inverter to operate.

Is that what "y'all" call micro grid?

 

[1201]

I guess the intent is to get a list of inverters that can do it "out of the box" not those you can "force" into doing it by getting a smart meter and programming/scripting a DIY solution to detect when we're exporting and if so charge from the grid at the amount limited by the export current.

Correct. However, in all cases a meter is involved. The hybrid inverter needs that to measure any current flowing to or from the grid

 

[1201]

New ruixu is advertising ac retrofit capable

 

[Lawrence_SoCal]

many hybrids can ac couple, but what if the grid is stable and one doesn't necessarily want to go through the trouble of ac coupling, but still wants to use excess energy from the grid tied inverter to charge a battery?
With an ac retrofit solution the hybrid inverter can measure any power flowing back to the grid from any sources, and divert that power to its battery for use later, so you just leave the grid tie inverter connected exactly as it always was.

Out of curiosity would it not also be possible to get an AC-coupled battery which had access to (or used its own CT clamps) to measure grid export, and adjust its own charging rate (load demand) accordingly....
I thought some less expensive grid-following battery setups watched grid... powering down if grid is down, and could obviously adjust input rates based on same monitoring (assuming battery connection/internals capable of such).

So, I'd think the scenario depends on desired outcome and panel output type (AC vs DC coupled). right? [testing myself]
As I re-read your original post, am I right to think you are presuming DC coupled panels (as you mention grid-tie inverter)? or did you mean that to include AC coupled micro-inverters?
- if AC coupled panels (micro-inverters), then no need for hybrid (grid-forming) inverter
- Possible to add AC coupled battery and still be grid-following, also without a hybrid inverter
- The reason to get a grid-forming hybrid inverter (with AC coupled panels) is if one wants local (micro-grid) power when main utility grid isn't working (grid down), or has/wants batteries that require DC charging input (vs those battery systems which have their own inverter)?

I ask to see if I'm understanding correctly. And this topic is of interest to me/relevant to my setup

 

[1201]

Out of curiosity would it not also be possible to get an AC-coupled battery which had access to (or used its own CT clamps) to measure grid export, and adjust its own charging rate (load demand) accordingly....
I thought some less expensive grid-following battery setups watched grid... powering down if grid is down, and could obviously adjust input rates based on same monitoring (assuming battery connection/internals capable of such).

So, I'd think the scenario depends on desired outcome and panel output type (AC vs DC coupled). right? [testing myself]
As I re-read your original post, am I right to think you are presuming DC coupled panels (as you mention grid-tie inverter)? or did you mean that to include AC coupled micro-inverters?
- if AC coupled panels (micro-inverters), then no need for hybrid (grid-forming) inverter
- Possible to add AC coupled battery and still be grid-following, also without a hybrid inverter
- The reason to get a grid-forming hybrid inverter (with AC coupled panels) is if one wants local (micro-grid) power when main utility grid isn't working (grid down), or has/wants batteries that require DC charging input (vs those battery systems which have their own inverter)?

I ask to see if I'm understanding correctly. And this topic is of interest to me/relevant to my setup

Ac retrofit (and ac coupled too) is if you already have a grie tie inverter, and you want to add battery storage.

With ac coupled you have to connect the output of the grid tie inverter to the hybrid inverter.

With ac retrofit you just leave the grid tie inverter exactly as it is and the smart hybrid inverter does its magic

 

[Balderdashian]

but still wants to use excess energy from the grid tied inverter to charge a battery?

I'm pretty sure every hybrid inverter can do this, including off-grid only ones, and the EG4 18kpv definitely can do it. Am I missing something here?

EDIT: So I think the issue with this "ac retrofit" issue is that it's not a binary thing. Like a fully "smart" system is the Victron Multi/Quattro with a GX can intelligently use CT sensors and a Victron Energy Meter to determine how much of the AC-input is coming from the grid versus other sources (like a grid-tied PV inverter).

But then there's EG4 12kpv and 18kpv, which isn't as smart but still smart in a way because they tell you to plug the grid-tied inverter into the generator input and set that input to AC-PV in the software. So it can still use AC-PV to charge batteries or power the critical load without drawing from the grid. I don't know if it can feed excess power from the generator input back to the grid, I believe it can't.

Then of course every "dumb" off-grid inverter still typically has an AC-input that it can charge batteries and power loads with. Your grid-tied inverter energizes your main electrical panel and your hybrid then pulls power from that. It doesn't know if it's drawing power from the AC-tied PV or the grid, but you can usually set like a schedule or something so that it only charges batteries during the sunlight hours.

 

[Quattrohead]

New ruixu is advertising ac retrofit capable

Looks like a Luxpower and therefore an EG4. Seems to me that Ruixu is copying EG4.

 

[1201]

I'm pretty sure every hybrid inverter can do this, including off-grid only ones, and the EG4 18kpv definitely can do it. Am I missing something here

No. Few hybrid inverters can do this

Looks like a Luxpower and therefore an EG4. Seems to me that Ruixu is copying EG4.

Specs don't match any luxpower products that i can find

 

[Balderdashian]

No. Few hybrid inverters can do this

Few hybrid inverters can charge the batteries from the AC input? Are you sure about that?

 

[1201]

Few hybrid inverters can charge the batteries from the AC input? Are you sure about that?

Every inverter charger can charge the battery from ac input.

Very few can sense when there is a generator connected to the ac input side and route that energy to the battery instead of letting it get exported to the grid

 

[Balderdashian]

Every inverter charger can charge the battery from ac input.

Very few can sense when there is a generator connected to the ac input side and route that energy to the battery instead of letting it get exported to the grid

Ok I misunderstood. And you're saying that the EG4 18kpv isn't a "retrofit" solution because you would have to route your AC-tied PV power to the new inverter's generator input.

 

[1201]

Ok I misunderstood. And you're saying that the EG4 18kpv isn't a "retrofit" solution because you would have to route your AC-tied PV power to the new inverter's generator input.

That's correct. 18k pv can ac couple but per report can't ac retrofit.

 

[Balderdashian]

The Sol-Ark 15k has CT sensors, so wouldn't that make it a retrofit solution?

 

[1201]

The Sol-Ark 15k has CT sensors, so wouldn't that make it a retrofit solution?

Not necessarily. It's not called out in the specs and i haven't seen any reports confirming it can, so for now I'm assuming it cannot

 

[Balderdashian]

Looking at this:
https://www.sol-ark.com/wp-content/uploads/2024/06/App-Note-AC-Coupling-Guide.pdf

and this:
https://diysolarforum.com/threads/sol-ark-15k-limited-power-to-home-vs-load.63121/#post-786178

It seems it can.

 

[1201]

Looking at this:
https://www.sol-ark.com/wp-content/uploads/2024/06/App-Note-AC-Coupling-Guide.pdf

and this:
https://diysolarforum.com/threads/sol-ark-15k-limited-power-to-home-vs-load.63121/#post-786178

It seems it can.

Not quite. Ac coupled is different from ac retrofit. Ac coupled you have to route the output of the grid tie inverter into the hybrid inverter

With ac retrofit you leave the grid tie inverter untouched

 

[1201]

@Balderdashian

 

[Lt.Dan]

Hmm... My Sol Ark 15k does have a "AC Coupled on Grid Side" button in the Smart Load tab, but no mention of it in the manual. I wonder if enabling this will use any excess power being sold back to be re-directed through the battery charger and into the batteries instead.

This is all skepticism, as I can't test this very easily.

 

[1201]

Hmm... My Sol Ark 15k does have a "AC Coupled on Grid Side" button in the Smart Load tab, but no mention of it in the manual. I wonder if enabling this will use any excess power being sold back to be re-directed through the battery charger and into the batteries instead.

This is all skepticism, as I can't test this very easily.

That's interesting. The they should fix their manual and explain what it does

 

[Lt.Dan]

That's interesting. The they should fix their manual and explain what it does

I agree. I wonder why it's not in there.

 

[Lawrence_SoCal]

Ac coupled is different from ac retrofit. Ac coupled you have to route the output of the grid tie inverter into the hybrid inverter

This is the first I'm noticing of these AC definitions 'coupled' vs 'retrofit'. just curious, are these industry standards, something common to this forum, or ?? I just tried searching a little and not seeing this terminology in common use... [but I didn't search that long/hard]

if it is common terminology, please point me to a source. thanks in advance
[sorry, for ambiguity... I know AC coupled is standard... it was the distinction with 'retrofit' that I meant not being common]

 

[1201]

I agree. I wonder why it's not in there.

I wonder if it's explained in the deye manual

Edit: didn't see anything in deye manual

I wonder if that setting is just to tell the solark that the is ac coupled pv on the grid input instead of the gen input?

This is the first I'm noticing of these AC definitions 'coupled' vs 'retrofit'. just curious, are these industry standards, something common to this forum, or ?? I just tried searching a little and not seeing this terminology in common use... [but I didn't search that long/hard]

if it is common terminology, please point me to a source. thanks in advance

Ac coupled is common terminology.

Ac retrofit is a new term