Not connected to grid, solar through house circuit possible?

[iampob]

HI,

trying to figure out what our best options are on a budget,
I got 16 370W NEC panels, and I'm slowly learning what the regulations are and permits required.
Our energy usage is pretty low, a 5kW system should cover it.

One of the things (of many!) I'm not understanding yet, is it possible to not be connected to PNMs grid but still have the solar providing energy to the house circuits, and when no solar is being produced it’ll use the grid?

I’m not against being connected to the grid, just wondering if it is possible without, as PNM now have additional compliance required, which may limit options for inverters/equipment.

effective March 29, 2024, all applications for interconnection must specify advanced inverters compliant with IEEE 1547-2018.

At the moment I don’t think we can include a battery, or at least not a large one,
loose calculations are about 2k for Unirac RM10, we have a TPO roof, which is pretty new and would like to use ballast mounts if possible. Then if we go with micro inverters about 2k for those.

thanks

 

[DIYrich]

Off grid, you need batteries. Consider cost of interconnection towards cost of off grid system.

 

[billvon]

loose calculations are about 2k for Unirac RM10, we have a TPO roof, which is pretty new and would like to use ballast mounts if possible. Then if we go with micro inverters about 2k for those.

thanks

Microinverters are not a great idea for a simple off grid system. If you want to go simple, get an AIO inverter (there are dozens to choose from) a battery and then arrange the solar to not overvolt the AIO's solar inputs.

 

[Gold Country Russ]

EP Cube w/at least 9.9KWH battery, add battery as needed, simple, quick, & legal everywhere.
NOTE: Signature Solar has on sale a few more days for $9,051 (free ship) less Fed tax credit = $6,472. & no need for microinverters or anything else.

 

[iampob]

Thanks for the info, PNM Interconnection is $150-300 max I think,
would love to get the EP Cube, looks very simple, unfortunately about 6K over our budget, and doesn't look like it has the IEEE 1547-2018 certification PNM are requiring.

So if we can't yet afford to go with a battery, is the only way to get solar coming through the house plugs to get the interconnection set up with PNM? or is it possible to not be connected to PNM, but have the system switch between solar when it's available and PNM when it's not?
I guess I'm a little confused about what "Off grid" can be, is it strictly that you don't have a power company account and no energy connection to them?, or can it be that that you do have their grid power coming in, but your solar system can work totally independently from them?
hope that makes sense.

 

[billvon]

So if we can't yet afford to go with a battery, is the only way to get solar coming through the house plugs to get the interconnection set up with PNM?

Yes, and you have to get a grid tie agreement as well, which means getting plans signed off, an inspection etc.

 

[DIYrich]

So if we can't yet afford to go with a battery, is the only way to get solar coming through the house plugs to get the interconnection set up with PNM? or is it possible to not be connected to PNM, but have the system switch between solar when it's available and PNM when it's not?

You might not need an interconnection agreement if the inverter cannot export to the grid, such as the 6000xp.

 

[iampob]

Yes, and you have to get a grid tie agreement as well, which means getting plans signed off, an inspection etc.

Thanks for confirming, makes the choices a lot simpler to navigate

 

[iampob]

You might not need an interconnection agreement if the inverter cannot export to the grid, such as the 6000xp.

 

[iampob]

Thanks, I'll check out what's possible with it.
This thread has some useful info I think, maybe I could have a separate panel with just some circuits running of the solar?

Can you connect an inverter to a single circuit in your house?

Heya folks! So I posted on Reddit and got a little bit of information and some resources but i really should have started here. In short, I'm wondering if you can tie an inverter to a single circuit in your house and not the whole panel itself. Possible? Thanks to Will, I've been tinkering...

diysolarforum.com

 

[iampob]

Looks like there are only a few states so far where IEEE 1547-2018 is required,
I haven't found a decently priced compliant inverter yet, the IQ8 micro inverters are compliant.

IEEE 1547™-2018 Adoption Tracker

The Institute of Electrical and Electronics Engineers 1547™-2018 Standard (IEEE 1547-2018) is a technical standard that establishes how distributed energy resources (DERs)—like solar and energy storage—can connect to the grid. In particular, it establishes interconnection requirements for smart...

irecusa.org

 

[DIYrich]

Looks like there are only a few states so far where IEEE 1547-2018 is required,
I haven't found a decently priced compliant inverter yet, the IQ8 micro inverters are compliant.

IEEE 1547™-2018 Adoption Tracker

The Institute of Electrical and Electronics Engineers 1547™-2018 Standard (IEEE 1547-2018) is a technical standard that establishes how distributed energy resources (DERs)—like solar and energy storage—can connect to the grid. In particular, it establishes interconnection requirements for smart...

irecusa.org

That is for exporting inverters. If he uses an off grid inverter, it is normal load to the grid.

 

[iampob]

Thanks,
so this requirement is only if we wanted to use PNM net metering? we could still have an interconnection to PNM without IEEE 1547-2018?

this is from PNMs page

Pursuant to 17.9.568.11 NMAC and the New Mexico Public Regulation Commission's Order Regarding Joint Status Report issued in the 23-00203-UT docket on December 14, 2023, is effective March 29, 2024, all applications for interconnection must specify advanced inverters compliant with IEEE 1547-2018 including proposed updates to existing systems.

 

[iampob]

Hi,

just stumbled across this video, one of the examples he gives is with dynamic bonding (at 2:50), it looks like it could work so we could have solar coming into the house circuits and be separate from the grid, so we wouldn't have to go through all the connection steps, and also need to find an inverter that's compliant with PNMs new requirement of IEEE 1547-2018.

Has anyone done something similar? or can point me towards any threads here that would contain details of this kind of set up, which inverters have dynamic bonding.

 

[robbob2112]

When researching while we were thinking of moving to Santa Fe one thing listed is a design and drawings stamped by a licensed electrical engineer.

Plans posted at entrance to the property, RSD for any panels on the roof, grid disconnect clearly marked and either at property line or at first point of entrance.

Maybe 8 rules to follow and each had many sub rules. But none of them much different than you would expect. All designed around poco personel or fireman safety.

 

[iampob]

Thanks, this is what we got from the County,
I've found out about the setback (which isn't mentioned in this doc) it needs to be 3ft on no less than 2 sides, I'm still calling around trying to get specifics the Manufactured Specifications (signed & sealed by Professional Engineer) part, the County engineers pointed me to the construction industry divisions department, I'm going to call them too see if I can get any details.

Do you think the grid disconnect part will still be needed if it's not capable of solar ever reaching the grid?
afaik the grid disconnect is a requirement from PNM, if this approach will work then in theory I have no need to interconnect with them or deal with their requirements, or at least that's how I'm understanding it at the moment (hopefully that's correct)

 

[DIYrich]

Do you think the grid disconnect part will still be needed if it's not capable of solar ever reaching the grid?
afaik the grid disconnect is a requirement from PNM, if this approach will work then in theory I have no need to interconnect with them or deal with their requirements, or at least that's how I'm understanding it at the moment (hopefully that's correct)

how would you connect the disconnect switch if you have no grid connection? An air gap of 200+ft is a pretty good "disconnect".

If you want a connection, but never export, then put a disconnect switch to keep them happy, and in case you ever do want to export.

 

[iampob]

cheers, it seems there'd be no requirements at all from PNM as we wouldn't be interconnecting, I like the idea of adding a disconnect switch into the design just incase we do ever need to go through the connection process.

The main thing I'm trying to learn at the moment is what type of inverters, and additional parts would be required to do the dynamic bonding set up shown in the video

 

[hwy17]

It's very unlikely that any hybrid system would not be considered technically interconnected. In any case, dynamic bonding should not be necessary.

I run a double conversion system, with no AC connection to my battery and inverter, just a charger, and it all uses the existing main panel NG bond.

Still if I were to try to get it permitted, which is legally required, it would probably be considered interconnected.