Newbie plan review please

[jc12311]

I started looking at generators for power outages and now I'm really getting sucked into solar DIY.

I'm still very new to solar and electrical in general but I have gone through the site resources and Will's videos and would love some help.

My primary goals are:
- Battery backup for power outages
- Use batteries during peak hours and recharge during off-peak hours to save on bill
- Setup must be transferable to new house (we'll be moving in a few years but want to start now)
- Ability to add solar later and grow the storage capacity over time

Current:
- 3000 sq ft, 2 story single family home in NC
- 200 amp service, electric HVAC, gas heat, gas stove/oven, gas tank-less water heater, woodworking tools like table saw
- Daily average usage: ~30kWh in winter and ~70kWh in summer

Proposed equipment:
- 1x G4 12000xp
- 4x 48v 100ah batteries (with 80% gives me around 16kWh?)

Questions:
- I believe the inverter has a built in transfer switch.
- Will this switch automatically during an outage?
- Will this charge the batteries when on-grid?
- Is this doable for under $8k with average installation costs?
- Will the 12000xp be enough with 100amp pass-through?
- Everything will be installed in my uninsulated garage/workshop. Would anything get damaged if
- Temps can be between 30-90.
- Sawdust and other particles will be floating around.
- Would the 30% tax credit apply to this? https://www.energystar.gov/about/federal-tax-credits/battery-storage-technology

Thanks!

 

[DIYrich]

12kpv or 18kpv will probably work better for you. The 12000xp is an off-grid inverter.
I would plan on taking the batteries and leaving the rest.

The 12kpv and power pro battery is about $6,600. I have no idea what permits, PTO, and electrician will cost you.

You should go with the 18kpv since you have 200a service.

If you go the Gridboss/Flexboss route, you can easily take the Flexboss and batteries (assuming you don't have solar), and leave behind the $1,800 gridboss.

 

[jc12311]

12kpv or 18kpv will probably work better for you. The 12000xp is an off-grid inverter.
I would plan on taking the batteries and leaving the rest.

The 12kpv and power pro battery is about $6,600. I have no idea what permits, PTO, and electrician will cost you.

You should go with the 18kpv since you have 200a service.

If you go the Gridboss/Flexboss route, you can easily take the Flexboss and batteries (assuming you don't have solar), and leave behind the $1,800 gridboss.

Thanks for the info @DIYrich !

I assumed off-grid was okay since I wasn't planning on sending anything back to the grid. Are you recommending the hybrid because of the 200amps or is there another benefit for my requirements?

 

[diysolar81]

While I don't have a big system like yours I feel the principle might apply. You could do a 100 AMP small panel off your main to distribute power. One breaker would supply the transfer switch connected to a Critical loads panel and the other break would supply the 12000XP Inverter AC Input. The AC Output of the Inverter would also be connected to the Transfer Switch. This way you can switch between Grid Power or Inverter power for the Critical Loads Panel.

 

[DIYrich]

I assumed off-grid was okay since I wasn't planning on sending anything back to the grid. Are you recommending the hybrid because of the 200amps or is there another benefit for my requirements?

If draw exceeds what the inverter can supply (large load, or low battery), the 12kpv and 18kpv have a cleaner transition to grid power.
For the 18kpv - yes, the 200a passthrough.

 

[PVGeezer]

If you're moving in a few years going through the effort of splitting your load into a main and a critical load panel might not be worth it. An 18K PV with the 200A passthrough doesn't require that because it can supply your entire load while the grid is up. You will need to manage your loads during outages but that can be done by switching off individual breakers.

It has a transfer switch and can charge the batteries from the grid if you want.

Yes the tax credit should apply.

 

[jc12311]

After doing some more research it looks like the Flexboss is the "better" version of the 18kpv, at least for my scenario.
From my understanding even if you only have 1 Flexboss you would still want the Gridboss to save on installation costs?

I also see the Griddboss does 200amp but the Flexboss does 90. Does that mean I'd need all 3 to hit 200amps?

Also, I think I'd like to go the server rack mount battery path. Are the eco-worthy ones compatible?

 

[WorldwideDave]

With all the gear you need plus labor I don’t feel confident in your 8,000 USD budget at all.

 

[jc12311]

With all the gear you need plus labor I don’t feel confident in your 8,000 USD budget at all.

Agreed. I was hoping to start small and add on to grow the system overtime but seems like that's not possible for what I'm asking for.

GridBoss+FlexBoss are around $6500 then some batteries would probably put me close to $10k before install.

 

[DIYrich]

I also see the Griddboss does 200amp but the Flexboss does 90. Does that mean I'd need all 3 to hit 200amps?

90a for the flexboss is passthrough. With the Gridboss, power passes through the GB, not the FB.

 

[PVGeezer]

Be sure to get enough battery so that you can use the full capacity of the inverter when the grid is down. For the Gridboss you want the battery to have a continuous current rating of 250A min.

 

[jc12311]

90a for the flexboss is passthrough. With the Gridboss, power passes through the GB, not the FB.

I did a bunch more reading and I think I get this now.

When the Gridboss is passing through from grid to my home it's 200amp the entire path and works just as if I didn't even have a Gridboss?

I assume when I'm not using the entire 200amps in pass-through mode that some of that could go to charge the batteries? I believe the Gridboss has a lot of programming options to determine how and when to distribute the load?

When pulling from solar/batteries, that will flow through to the Flexboss and I will be limited to 90amp/12kw max, unless I get 2 then I'll have 180amp/24kw?
In my situation with only 1 Flexboss, I would move my non-critical loads to the Gridboss and it would not power those when on battery... or however I program the Gridboss to handle it?

Later, adding another Flexboss would be much simpler and cheaper since I'm already using the Gridboss?

Comparing this to the 18kpv for example, it has a 200amp pass-through and 18kw output max so if I ever wanted to go past the 18kw limit (which I think I do if I want to load my entire system?) I would need another one and the install cost would be much greater? Plus the cost to move to the next house would make it prohibitive. The Flexboss would be the only thing I need to leave behind going the Boss route?

And thanks for helping me understand all of this.

 

[jc12311]

Be sure to get enough battery so that you can use the full capacity of the inverter when the grid is down. For the Gridboss you want the battery to have a continuous current rating of 250A min.

So the 48v 100ah Eco-worthy batteries won't work since they're 100ah?
Sorry for the dumb questions, I'm really new to this stuff.

 

[MisterSandals]

continuous current rating of 250A min.

250A is a rate (like miles per hour)

So the 48v 100ah Eco-worthy batteries won't work since they're 100ah?

100Ah is an amount (like miles)

Your 4x 48V batteries in parallel will have a combined current rating of 400A (sum total when paralleled)

 

[DIYrich]

For the Gridboss you want the battery to have a continuous current rating of 250A min.

Gridboss is not the inverter, so it doesn't need batteries. Flexboss, 18kpv, 12kpv ate the inverters. Get batteries to max out the inverter.

 

[DIYrich]

So the 48v 100ah Eco-worthy batteries won't work since they're 100ah?
Sorry for the dumb questions, I'm really new to this stuff.

When in parallel, amps add. Lifepo4 I'd generally able to output its capacity over 1 hour, so a 100ah battery can deliver 100a. But, in something like the Powerpro, the 280ah battery is limited to 200a by the bms.

 

[DIYrich]

When the Gridboss is passing through from grid to my home it's 200amp the entire path and works just as if I didn't even have a Gridboss?

Correct.

I assume when I'm not using the entire 200amps in pass-through mode that some of that could go to charge the batteries?

Correct.

I believe the Gridboss has a lot of programming options to determine how and when to distribute the load?

Some ability.

When pulling from solar/batteries, that will flow through to the Flexboss and I will be limited to 90amp/12kw max, unless I get 2 then I'll have 180amp/24kw?

Correct. But the 90a limit assumes pv. Lower limit for battery only.

In my situation with only 1 Flexboss, I would move my non-critical loads to the Gridboss and it would not power those when on battery... or however I program the Gridboss to handle it?

Critical loads go on the "backed up" connection.
Non-critical can go on "not backed up" or "smart load".

Later, adding another Flexboss would be much simpler and cheaper since I'm already using the Gridboss?

that's the idea.

Comparing this to the 18kpv for example, it has a 200amp pass-through and 18kw output max so if I ever wanted to go past the 18kw limit (which I think I do if I want to load my entire system?) I would need another one and the install cost would be much greater? Plus the cost to move to the next house would make it prohibitive. The Flexboss would be the only thing I need to leave behind going the Boss route?

you don't have to leave anything. You can write the listing for the house however you want.

but, removing the GB is hard.

if you have panels, removing the FB makes the panels unusable.

If you are going to be in the house less than 10 years, don't bother with panels.