Utility interconnection vs Reverse current relay

Status
Not open for further replies.

coop3339

Senior Member
Location
NJ
Hi Everyone,

I have a situation where a utility is demanding we pay for a transformer upgrade before they will approve interconnection. This is not unusual in itself but what is unusual is that the transformer is 3x as large as the system we are installing and is less than 5 years old. The transformer is 500kVA and the system is 175KW AC. The facility has high electrical usage and a 1600A service. I think the utility under sized the transformer from the start and are now trying to get us to pay for the upgrade. My question is, if we install a reverse current relay and don't allow the system to export power, can they still force us to pay for the transformer change? or would they have to approve it because it is not exporting power. The building has plenty of load so the system would not have to clip too often.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Hi Everyone,

I have a situation where a utility is demanding we pay for a transformer upgrade before they will approve interconnection. This is not unusual in itself but what is unusual is that the transformer is 3x as large as the system we are installing and is less than 5 years old. The transformer is 500kVA and the system is 175KW AC. The facility has high electrical usage and a 1600A service. I think the utility under sized the transformer from the start and are now trying to get us to pay for the upgrade. My question is, if we install a reverse current relay and don't allow the system to export power, can they still force us to pay for the transformer change? or would they have to approve it because it is not exporting power. The building has plenty of load so the system would not have to clip too often.
The only potential, though weak, argument I see is that POCO may want aclarger transformer to improve voltage regulation as the output of the PV system varies.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I think this is really more of a regulatory question than a technical one. It depends exactly how the state's net-metering law is written. Also you'd need to AHJ approval.
 
Status
Not open for further replies.
Top