Green Meter Adapter

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Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
Hello, we (building department) received an inquiry about installing a new PV system using a "Green Meter Adapter" per the attached specs. Assuming the plans meet 2019 CEC (and CRC/CFC) requirements we will permit the installation. Just wondering if anybody has experience with these and would be willing to share pros/cons and any warnings or red flags that I should be watching out for. Thanks!
 

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  • TD-7001B-007 Green Meter Adapter.pdf
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texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
Hello, we (building department) received an inquiry about installing a new PV system using a "Green Meter Adapter" per the attached specs. Assuming the plans meet 2019 CEC (and CRC/CFC) requirements we will permit the installation. Just wondering if anybody has experience with these and would be willing to share pros/cons and any warnings or red flags that I should be watching out for. Thanks!
These are like meter mounted generator transfer switches in that it will be the POCOs call as to whether it is permitted.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Hello, we (building department) received an inquiry about installing a new PV system using a "Green Meter Adapter" per the attached specs. Assuming the plans meet 2019 CEC (and CRC/CFC) requirements we will permit the installation. Just wondering if anybody has experience with these and would be willing to share pros/cons and any warnings or red flags that I should be watching out for. Thanks!

It's a supply side connection, so it complies with the CEC.
 

Zee

Senior Member
Location
CA
i believe they are often limited to 60A of solar, which is plenty and often more than the MSP would allow for a load side connection per 120% rule.
 

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
Yes, that's the end goal here, they can't upsize the main panel to using this adapter allows them more solar. I was just wondering what the downside is, other than the 60A limit. There's got to be a downside right? Or we would have seen one before... Not certain, but this may be the first one in our entire county. Definitely the first for the city I'm in.
 

Carultch

Senior Member
Location
Massachusetts
Yes, that's the end goal here, they can't upsize the main panel to using this adapter allows them more solar. I was just wondering what the downside is, other than the 60A limit. There's got to be a downside right? Or we would have seen one before... Not certain, but this may be the first one in our entire county. Definitely the first for the city I'm in.

The biggest downside is whether the utility will allow you to using it or not. You need to clear it with the utility first, since it is common for a utility to restrict how you can connect to the socket that houses their meter.

Vermont's Green Mountain Power was the first utility to accept this technology. Unfortunately the manufacturer doesn't publish a list of utilities that approve it, which would help tremendously.
 

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
Interesting. The contractor who contacted me was requesting a "pre-approval" email from us before he could get permission from PG&E. Since PG&E has a guideline bulletin that outlines their requirements, and it's technically on their side of the meter I'm surprised they want pre-approval from us. Maybe everybody is being extra cautious as it appears to be the first and only in this area. From what I could find this is not a new thing though.

Anybody live in an area that prohibits these?
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I think the downside is the extra bureaucratic steps. Plus utility has its extra fees to come out and put it in for you. Adds to the soft costs solar companies are always trying to minimize. FInally, the window between 40A on a typical 200A and 60A isn't going to cover every system, and for systems that size the issue is usually solved faster and cheaper by downsizing the main to 175A.

I believe in San Francisco they would not approve this because they do not allow LFMC for service entrance conductors. Not that I've tried.
 

pv_n00b

Senior Member
Location
CA, USA
Interesting. The contractor who contacted me was requesting a "pre-approval" email from us before he could get permission from PG&E. Since PG&E has a guideline bulletin that outlines their requirements, and it's technically on their side of the meter I'm surprised they want pre-approval from us. Maybe everybody is being extra cautious as it appears to be the first and only in this area. From what I could find this is not a new thing though.

Anybody live in an area that prohibits these?

The contractor is just verifying that the building department will approve it, and PG&E requires that approval. These are still not used that often and maybe the contractor was burned in the past by another building department. I would not see this request as unusual and the contractor is asking permission and not forgiveness, encourage this practice.
 

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
The contractor is just verifying that the building department will approve it, and PG&E requires that approval. These are still not used that often and maybe the contractor was burned in the past by another building department. I would not see this request as unusual and the contractor is asking permission and not forgiveness, encourage this practice.
Thank you for that perspective. Looking at it that way it seems much more reasonable for the contractor to ask for pre-approval, not because PG&E requires it, but because he doesn't want to spend (waste) time working on this just to get blocked by an unreasonable AHJ.
 
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Zee

Senior Member
Location
CA
What are the downsides of using the GMA?

Per PG&E:
- 125A or smaller services only
- not allowed on meters fed by overhead services (in my area almost all!)

Per Code:
separate AC disco required = more work and some cost

Per reality:
the one time I tried, PG&E was quite rude, unresponsive and claimed requirements (overhead feed not OK) that were simply not found in their BULLETIN that they directed me to. They then referred me to a different version than the one on their own website and demanded those reqs.
It was very frustrating..... and huge delay for customer and I!

In other words...... if possible to place a PV breaker (load side connection) or downsize main breaker......that is often the way to go.
If 200A MSP ---> replace w/ 175A main brkr for 65A PV.
If 125A MSP ---> replace w/ 110A for 40A PV.

If 100A MSP --->
The GMA could be great option, if customer does not want to pay $4-7k for a new, 200A service.


These reasons may be why I, as an installer, do not use them hardly ever.
 

Zee

Senior Member
Location
CA
FYI
PER PG&E:

The GMA is not allowed on electric meter panels that; have deteriorated parts, are
rated above 125 amps, do not meet the equipment clearances, located on poles,
located inside cabinets, have a overhead to underground service adapter, are a
stand alone meter socket, or where the GMA and/or wires cannot be routed and
terminated appropriately. The review and approval are at the discretion of the PG&E
Meter Engineering and Field Metering personnel.
When a GMA cannot be installed
an upgrade to the electrical panel and service may be required to support the

customers generating system.
 

Zee

Senior Member
Location
CA
Oh and pre approval is a requirement of PGE. That is why contractor is asking you, the city.


" 4. Pre-approval documentation and permit from the AHJ allowing the interconnection of
the customer’s generation system to the GMA. "
 

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
Zee, thank you very much for your input! This explains why we have never seen this before. It seemed like such a simple solution for this situation but now I see that it is not simple at all. PG&E seems to cause lots of stress for people, it's really unfortunate. I gave the contractor the pre-approval but have yet to hear back, presumably he's banging his head against the wall trying to get PG&E to cooperate?
 
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