Hybrid Solar - Can I Place Inverters and Batteries Near Array and Away From Main Panel?

I would like to do a ground mount PV array and the best location for it is about 300' from my house. I would rather not have the inverters and batteries in/on my house reasons being space, aesthetics, safety with kids, and potential for fire hazard. My first preference would be to have the inverters and batteries at the location of the PV array (ok with building a small shed to house equipment). I know this would be simple for a grid tie only system but I want PV power to my house when the grid is down. Do I have any options?

More details:
-Planning 38Kw PV array, I already have 24 530W JA Solar panels and am planning to buy a pallet of 31 more
-Workshop has CNC machining centers and I use a lot of power
-Selling PV generated power back to the grid is preferred but not a priority
-Having PV generated power at shop when grid is down would be nice but not a priority
-Having PV generated power at house when grid is down IS a priority
-Would preferer not to have grid tie only and PV backup circuits separate, rather just backup the whole house and not draw too much power at once
-Planning on battery backup but undecided on size
-Located in Arizona, power company is APS

You may be able to use something like this https://www.currentconnected.com/product/sok-12-slot-outdoor-battery-rack/ near your PV array and have the Inverter mounted on the outside of the battery rack; then just use a critical loads panel in the house with MTS/ATS to switch from the grid to PV array when the power is out.

Selling PV back to the grid would require having grid tie with power company though...

If you wish to do whole house back-up at the 400A main panel its going to require 2 runs of 295'. Utility power would need to feed into the inverter(s) at the ground mount location then the inverter output would supply the 400A main panel. Where does utility power originate from? Could you have the utility drop relocated to the proposed ground mount location then its only one run up to the house.

The least amount of wiring is going to be running the PV DC leads to the house and putting the inverter and batteries there. PV is high voltage, so takes less copper to run it places.

You could make a little accessory shed on the side of the house for the equipment to keep it outside.

You didn't give location, so we have no idea what climate you have and whether being outside is an option. Providing more information will lead to better guidance from others.

Mike C.

BentleyJ said:

If you wish to do whole house back-up at the 400A main panel its going to require 2 runs of 295'. Utility power would need to feed into the inverter(s) at the ground mount location then the inverter output would supply the 400A main panel. Where does utility power originate from? Could you have the utility drop relocated to the proposed ground mount location then its only one run up to the house.

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2 runs to carry 38kW at 240V for 295' is what I came up with needing too. Sounds expensive and maybe too much voltage drop from the utility company transformer I'm on. I was hoping there was another way I didn't know about. Sounds like there isn't.

Utility power comes in the 400A panel from underground from a transformer on a pole about 250' north of the house (north is up in the diagram). Relocating utility power is probably cost prohibitive.

mciholas said:

The least amount of wiring is going to be running the PV DC leads to the house and putting the inverter and batteries there. PV is high voltage, so takes less copper to run it places.

You could make a little accessory shed on the side of the house for the equipment to keep it outside.

You didn't give location, so we have no idea what climate you have and whether being outside is an option. Providing more information will lead to better guidance from others.

Mike C.

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Copy on PV DC leads to the house. That's what figured is the best way to do it so far apart from not being able to put inverters and batteries at the PV array like I want. Sounds like I can't have my cake and eat it too. An accessory shed on the side of the house seems like the best compromise. I have a cut in the grade that steps up almost 6' in height about 20' north of the house I need to build a retaining wall for. I could probably inset a block wall utility shed into the hillside as part of the retaining wall and make it look nice.

I'm located in central Arizona near Prescott, AZ.

harjms said:

You may be able to use something like this https://www.currentconnected.com/product/sok-12-slot-outdoor-battery-rack/ near your PV array and have the Inverter mounted on the outside of the battery rack; then just use a critical loads panel in the house with MTS/ATS to switch from the grid to PV array when the power is out.

Selling PV back to the grid would require having grid tie with power company though...

Click to expand...

Thanks that might work as a utility shed for outside the house.

goldenfab said:

I'm located in central Arizona near Prescott, AZ.

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The high desert can have cold temps, your record low is -29 C (-21 F). You will need to pay attention to the Voc rise in cold so you don't blow out your inverter MPPTs. Also, if the battery is not in conditioned space, then your battery needs a heater and that will drain energy during the night and during the nights with the least solar. The battery wants to be +5 C to +45 C for best operation of LFP cells.

An insulated shed with a thermostatically controlled ventilation system would probably be in order. In the heat, say anything over 30 C, it runs air through the shed to keep the equipment cool. In the cold, it shuts down and seals off the shed so the waste heat of the inverter heats it up the shed insides and helps reduce the battery heater energy use during the night. Some thermal mass inside the shed helps retain this heat, say concrete or other mass.

Insulating the battery by itself usually doesn't work since they evolve some heat during heavy charging and discharging and you don't want to overheat them.

Maybe a small heat pump for the shed would work. Given the rather extreme temperature cycling of your site, keeping the equipment at a moderately steady temp would extend its life.

In any case, give some thought to how you will manage the temperature and heat output of the equipment.

Mike C.