Xcel Energy Colorado

[gbpnkans]

I would like to install solar panels and use it internally within the house and grid as backup. I do not want to sell any power generated to grid.
I do understand I need to get permission from city and hoa for house improvements.
Do I need to get permission from Xcel Energy in colorado for the same?

 

[timselectric]

You don't need approval from the utility company unless you can export to the grid.

 

[timselectric]

Clarification
It doesn't matter if you want to export, or not.
It only matters if the equipment that you choose can export.

 

[zanydroid]

One tradeoff is paying extra for fancier hardware but simpler installation & design and ability to use grid to assist with heavy loads. The extra cost comes from the hardware to help simplify and extra cost for grid compliant hardware.

Or oversize a cheaper off grid setup to compensate for needing to carry a large % of max load totally by the off grid system.

Depends also on how code compliant you want. If you forgo inspections you can harvest the full gap. If you have inspections then you are kind of forced into the higher cost UL9540 hardware already.

I know which one Timelectric would pick ?

 

[zanydroid]

It only matters if the equipment that you choose can export.

Some equipment that can export can have it disabled. Not all, and sometimes it requires a PhD in reading Chinglish manuals to figure out how to achieve it.

 

[timselectric]

Some equipment that can export can have it disabled. Not all, and sometimes it requires a PhD in reading Chinglish manuals to figure out how to achieve it.

Doesn't matter if you set it to not export.
Any grid-tied system requires approval from the grid supplier.
If not planning to export. Just use an off grid AIO.
You still have grid for backup. But no approval needed.

 

[timselectric]

I know which one Timelectric would pick ?

I already chose mine. But I don't need approval from anyone but the bank account. lol

 

[timselectric]

If I were going to recommend anything, based on price and features. It would probably be the EG4 6kxp.
But it's new, and needs more time in the world. Before I can recommend it. However, it really does look promising.

Just don't confuse it with the EG4 6kex. It's had some issues and I definitely can't recommend it.

 

[zanydroid]

Any grid-tied system requires approval from the grid supplier.

I mean the grid relay is set for SBU, not zero export. If it is correctly set to SBU behavior (ie grid and inverter are interlocked to be mutually exclusive) instead of parallel operation the POCO should have no business caring. Zero export the POCO would care.

The advantage of an off grid AIO is that it cannot be accidentally set in the wrong mode unless the firmware has a senior moment and messes it up.

EG4 6kxp

This one is pretty nice and scalable, however it’s not a code compliant ESS. It’s almost there though.

 

[timselectric]

I mean the grid relay is set for SBU, not zero export. If it is correctly set to SBU behavior (ie grid and inverter are interlocked to be mutually exclusive) instead of parallel operation the POCO should have no business caring. Zero export the POCO would care.

They care, if it can.
Some people have been sneaking by. But if the utility catches you. You are in trouble.

The advantage of an off grid AIO is that it cannot be accidentally set in the wrong mode unless the firmware has a senior moment and messes it up.

It's not controlled by firmware.
Well it is, but the firmware can't choose to export.
The relay can only connect to one or the other.

Unless it's capable through a SUB mode.
Like my Growatt's.

This one is pretty nice and scalable, however it’s not a code compliant ESS. It’s almost there though.

I thought that they said that certification was done.
Maybe not, yet?

 

[zanydroid]

They care, if it can.
Some people have been sneaking by. But if the utility catches you. You are in trouble.

How would they detect a hybrid that is properly set up in an SBU mode, ie utility relay closed only during U mode, and set up to prevent even momentary parallel operation when switching modes?

That said I’m pretty sure I’ve seen a lot of messages about people misunderstanding/misconfiguring to achieve that.

It's not controlled by firmware.
Well it is, but the firmware can't choose to export.
The relay can only connect to one or the other.

Unless it's capable through a SUB mode.
Like my Growatt's.

There are probably some AIO where the firmware implements the interlock in software, others where it is a mechanical relay interlock.

I thought that they said that certification was done.
Maybe not, yet?

I thought it was for the 18kpv only. I could be wrong. They would have needed to submit for every new inverter. And keeping the cert just in 18kpv might be good for differentiation so they can harvest more ?

 

[timselectric]

How would they detect a hybrid that is properly set up in an SBU mode, ie utility relay closed only during U mode, and set up to prevent even momentary parallel operation?

They can't.
But the question wasn't can you sneak by without approval. It was asking if approval was required by the utility company.

There are probably some AIO where the firmware implements the interlock in software, others where it is a mechanical relay interlock.

Right
Most off grid AIO's use a relay that can only connect to inverter or grid. (Never both)
But a few can. It depends on if they have SUB mode. And how they implement it.
My Growatt's could export by accident. If there was a firmware glitch. I'm not sure which other products work this way.

I thought it was for the 18kpv only. I could be wrong

I'm not sure either, now.

 

[gbpnkans]

Thanks for the detailed discussion. That helps a lot.

 

[ThatOneRoadie]

I'm working with Xcel in Colorado to try to add an 18KPV as an Interconnected Distributed Energy Resource (DER). Fair warning: The application fee for the 18KPV is $1000, no matter how much solar is behind it (because the "Nameplate" AC Output rating is 12kW and therefore it's a DER 10kW-250kW and costs $1000 instead of $100, so go big on the solar side). They've also had some kind of denial/more information needed at pretty much every step along the way (I'm a month into the application at the moment, and have Metering approval but currently a denial from Engineering because my shared secondary has too much Aggregate DER and the Aggregate DER on my Interconnect is over 15% of peak load.

I'm currently waiting for a meeting with engineering where they're probably going to try to make me pay for a share of a substation upgrade in order to allow my system on the grid.

At this point, Going entirely off-grid and using the grid as a backup would definitely be the less frustrating option; guess I should've done that.