Feedback on use of all-in-one switching Growatt to supplument home grid system

bobthebuider

New Member
Joined
Apr 16, 2021
Messages
2
Hello all.

I'm looking for feedback on my planned use of a Growatt to supplement my home grid power. I have seen plenty of examples of using the Growatt inverter with AC input. But I have yet to see anyone bisect a singe circuit coming from a home panel and into a home. It seems like an obvious use, but I haven't seen an example of that specific application and I'm wondering why.

My idea was to mount a Growatt next to my home's panel and put one of my home's circuit's on the growatt (kitchen circuit with fridge). The goal would be to shave off some from my power bill, but also to be able to have one circuit of the house with power if there is an outage.

My thought was to put the AC input to the growatt directy from the panel from my kitchen circuit. Then connect the AC output to the same line going to my kitchen. Then during the day the refrigerator and appliances woud be on solar and when batteries run dry it would automaticaly switch to the grid.

I was thinking of spending about $3000 for a 1 kW array (10 x 100W Rich Solar panels) + 24 V Growatt and ~200 A-h SOK battery.

Any feedback is appreciated.
Thanks.
 
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JAS

Solar Enthusiast
Joined
Jan 16, 2020
Messages
201
I'm also interested in doing something very similar and I agree, it is hard to find any examples of such a setup. (via GroWatt, MPP, Victron, etc.). I'm still deciding if I want to put the AIO unit right next to my panel in the basement or out in my detached garage and run heavy wiring back/forth. If I go with the basement install, I'm going to want a UL listed product and batteries (Battleborn). Otherwise, I think I can get away with non-UL listed stuff (IE: Cheaper) out in the garage

1 Note: I think you could do much better on pricing for your solar though... For instance, I'm looking at new 400W 48v panels for $255 via local pickup on Facebook marketplace. Two or three of those would be cheaper than 10 x 100W 12v panels. (Just have to watch that the total open circuit voltage isn't too high for the MPPT charge controller)
 

Jsomo

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Apr 20, 2021
Messages
1
I'm looking into the EXACT same thing, except it's for other reasons.

I want to put in a small sub panel and power all my electronics, TVs, and Lighting off of it with that sweet even pure sine wave. My power fluctuates a lot with loads like my A/C, Dehum, Two sump pumps, dryer... on top of not having the cleanest electricity to begin with. I'm sick of dimming lights, I'm sick of brown outs, I'm sick of my TVs randomly losing signal when one of these loads turn on. I have battery backups everywhere everywhere to help, but it isn't enough, especially if I need to run generator power (a few times a year).

Utility and multiple electricians say that's just how it is...I have new everything all the way up to the pole so I tend to think it's the utility vs the loads I have in my house.

Welp, time to take things into my own hands. The only "grid tie" part I want with this system is if there isn't enough solar. I don't care about saving money, I just want clean, uninterrupted power to things that matter and no need for battery backups anymore.

Edit: I guess I should mention it's completely possible with the Growatt. You can connect the hot right to an independent sub panel and ground it. Then plug the utility into it's own 20amp circuit on your main panel. My issue is trying to keep this affordable and meet code.
 

bobthebuider

New Member
Joined
Apr 16, 2021
Messages
2
I'm looking into the EXACT same thing, except it's for other reasons.

I want to put in a small sub panel and power all my electronics, TVs, and Lighting off of it with that sweet even pure sine wave. My power fluctuates a lot with loads like my A/C, Dehum, Two sump pumps, dryer... on top of not having the cleanest electricity to begin with. I'm sick of dimming lights, I'm sick of brown outs, I'm sick of my TVs randomly losing signal when one of these loads turn on. I have battery backups everywhere everywhere to help, but it isn't enough, especially if I need to run generator power (a few times a year).

Utility and multiple electricians say that's just how it is...I have new everything all the way up to the pole so I tend to think it's the utility vs the loads I have in my house.

Welp, time to take things into my own hands. The only "grid tie" part I want with this system is if there isn't enough solar. I don't care about saving money, I just want clean, uninterrupted power to things that matter and no need for battery backups anymore.

Edit: I guess I should mention it's completely possible with the Growatt. You can connect the hot right to an independent sub panel and ground it. Then plug the utility into it's own 20amp circuit on your main panel. My issue is trying to keep this affordable and meet code.

Wow. you really opened my eyes with the cheaper panels. At $50/250Watt, I'd prefer to put up a 3kW array and a 48V Growat and have that lead to a small subpanel as you suggested. I could put a few house circuits on the subpanel.
  1. Is there a limit on the AC current input to the Growatt? The videos I've seen by Will Prowse show a single extension cord as input, which i assume is not intended to carry more than a few amps. I think I would want 25 amps AC input to support a few circuits on the sub panel.
  2. I see quite a few peope are using the used SanTan solar panes here. What other sources of panels would you recommend?
 

JAS

Solar Enthusiast
Joined
Jan 16, 2020
Messages
201
Take a look on Craiglist and Facebook Marketplace local to you for better prices on panels
 

ocorrea73

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Jul 6, 2020
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2
Hola a todos.

Estoy buscando comentarios sobre el uso planificado de un Growatt para complementar la energía de la red de mi hogar. He visto muchos ejemplos de uso del inversor Growatt con entrada de CA. Pero todavía no he visto a nadie bisecar un circuito único que viene de un panel de inicio a un hogar. Parece un uso obvio, pero no he visto un ejemplo de esa aplicación específica y me pregunto por qué.

Mi idea era montar un Growatt junto al panel de mi casa y poner uno de los circuitos de mi casa en el growatt (circuito de cocina con nevera). El objetivo sería reducir algo de mi factura de energía, pero también poder tener un circuito de la casa con energía en caso de un apagón.

Mi idea era poner la entrada de CA al growatt directamente desde el panel de mi circuito de cocina. Luego conecte la salida de CA a la misma línea que va a mi cocina. Luego, durante el día, el refrigerador y los electrodomésticos funcionarían con energía solar y, cuando las baterías se secasen, cambiarían automáticamente a la red.

Estaba pensando en gastar alrededor de $ 3000 por una matriz de 1 kW (10 paneles solares ricos de 100 W) + Growatt de 24 V y una batería de ~ 200 Ah SOK.

Se agradece cualquier comentario.
Gracias.
Hola yo lo tengo con una bateria de 24v 200ah gracias
 

NHRenewables

New Member
Joined
Sep 16, 2021
Messages
25
What is being suggested is all doable. First, I‘d do some more research and an energy audit for your loads. Better to size a system that you can grow into as your pocketbook allows than having to continually upgrade.

Some of the newer AIO inverters have brought the costs and ROI down considerably. When I first got into the industry, $6 per watt with tax incentives was the best you could do on costs. You’ll find that you can source solar panels @ .50c-75c/watt new. The days of 100W are gone. If you undersize your system without scalablity, you might shortchange your plant.

I’d avoid FB and Craigslist as I find people trying to resell old equipment (it does degrade) at unrealistic prices. My biggest complaint personally these days is the costs of racking hardware and copper costs. $25 dollars of hardware to rack a 10 year old 100w panel is not a good cost proposition. Try pricing a 2/0 spool of copper now!
 

NHRenewables

New Member
Joined
Sep 16, 2021
Messages
25
You really don’t need a transfer switch. If you commit to the plan, you add a more affordable subpanel to the wall next to your main panel and AIO, add an appropriate sized GFCI breaker to your main to feed your inverter, and relocate your critical loads to your new critical load panel. As your system and pocketbook can absorb additional circuits, you can move them over.
Please ensure you earth ground your system appropriately as these system have a hot neutral when running in battery mode. They are NOT internally bonded. Consult an electrician if these last two statements confuses you, it can save a life.
 
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NHRenewables

New Member
Joined
Sep 16, 2021
Messages
25
Wow. you really opened my eyes with the cheaper panels. At $50/250Watt, I'd prefer to put up a 3kW array and a 48V Growat and have that lead to a small subpanel as you suggested. I could put a few house circuits on the subpanel.
  1. Is there a limit on the AC current input to the Growatt? The videos I've seen by Will Prowse show a single extension cord as input, which i assume is not intended to carry more than a few amps. I think I would want 25 amps AC input to support a few circuits on the sub panel.
  2. I see quite a few peope are using the used SanTan solar panes here. What other sources of panels would you recommend?
He’s just testing in that config. it works, but not safe for a long term configuration. Growatt specifically calls for mounting the units to concrete fiberboard for fire safety.
 

Sky-HHI

On Hilton Head Island in South Carolina
Joined
Sep 24, 2019
Messages
158
I use a Reliance 6 circuit transfer switch with my mpp AIO. It is the safest way to do what you want to do. It will always keep the grid power and your solar generated AC separate. There is no chance of back feeding from one system to the other. You also have the choice of what circuits wired thru the transfer switch you want to run off your inverter and batteries. If I have a lot of cloudy days and my batteries are low then I only use the solar power for some lighting, when the batteries are full them I connect all 6 circuits to the solar power. If I need to work on my system or the AIO then I can switch all the circuits back to the grid. The way I understand using a sub panel , if the AIO is out of the loop (broken or dead) then the sub panel will not work.
 

BMcL

Solar Addict
Joined
Sep 5, 2021
Messages
401
If you are going to move some critical loads over to solar like your heat pump, microwave, water heater and clothes dryer, I would look at a heavy-duty low frequency inverter that can take an electrical surge (like when a compressor starts up). I have an electrical contractor friend who is using a Sungold inverter and they look very reliable :

I also like the MPP Solar LVX6048 but it isn't nearly as heavy-duty as the Sungold.
 

NHRenewables

New Member
Joined
Sep 16, 2021
Messages
25
I use a Reliance 6 circuit transfer switch with my mpp AIO. It is the safest way to do what you want to do. It will always keep the grid power and your solar generated AC separate. There is no chance of back feeding from one system to the other. You also have the choice of what circuits wired thru the transfer switch you want to run off your inverter and batteries. If I have a lot of cloudy days and my batteries are low then I only use the solar power for some lighting, when the batteries are full them I connect all 6 circuits to the solar power. If I need to work on my system or the AIO then I can switch all the circuits back to the grid. The way I understand using a sub panel , if the AIO is out of the loop (broken or dead) then the sub panel will not work.
I guess you’re using it more as a battery backup solution. The investment in an AIO is not trivial and I see it as a better solution for self sufficient AC coupling in how the grid is going to change. My expectation for the AIO is to have the same uptime as the grid and be slowly adopted as a standard for household systems.

I‘m treating the Growatt as an enhancement to the grid as opposed to an alternative. With an existing grid tie solution on the main panel, the downstream AIO provides a battery backup option without having an excessively large battery system. The AIO can call on the reserve capacity saved up from net metering.

This smart-grid solution has larger implications for a more stable distributed grid reducing overall variable demands and smoothing the peaks and valleys grid providers need to manage currently. Changes that we‘re making will result in better forecasting of power demands. PG&E for example in California could better manage the risks of forest fires by depowering areas during hot mid-day conditions and repowering those areas during cooler nighttime conditions.

If you were to find AIO produced power upstream of the AIO, that would be the fault of the installation/installer and not the AIO. Grid > Main Panel > AIO > Critical load Subpanel design also provides a set it and forget it approach that would be the most appealing to the masses looking for a resilient solution.
 

ocorrea73

New Member
Joined
Jul 6, 2020
Messages
2
Hola yo lo tengo con una bateria de 24v 200ah gracias
Hola, solo tienes que poner un subpanel pero alimentado por el growatt y te pasan los circuitos que necesitas, tengo toda la iluminación y las neveras, ventiladores de techo, gracias.
 

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