Supply side vs Load side connections - utility preferences

[isurf]

With the newest edition of California Title 24 PV requirements are getting much larger for new commercial buildings. As a result the PV interconnection breaker is also growing. From what I have read on this forum and others, utility companies don't like supply side connections. That being said is it a better practice to upsize the bus on the load side and provide a load side connection per 705.12 or trudge forward with utility coordination for a supply side connection? Any input much appreciated!

 

[pv_n00b]

Personally, I prefer a load-side interconnection in new buildings. But then again I see time and time again where a developer will call in the PV company after all the electrical is complete and expect them to shoehorn in a PV system into a new building with no prior planning. Even when T24 requires PV to be baked into the design before it is permitted. In that case, new service SWBDs often have to get supply-side interconnections and new buildings get conduit running down the outside walls that could have easily been internal. I consider it a failure of the developer not to bring in the PV team for the initial design.

Saying that utilities don't like supply-side interconnections is painting with a very broad brush. Some utilities, particularly small municipal utilities, don't allow supply-side interconnections. But most utilities are fine with it. The big three IOUs in CA that cover 80% of the customers in the state allow supply-side interconnections.

 

[jaggedben]

I tell people that bringing in the solar late is like bringing in HVAC late. Especially if they also want energy storage.

 

[isurf]

Personally, I prefer a load-side interconnection in new buildings. But then again I see time and time again where a developer will call in the PV company after all the electrical is complete and expect them to shoehorn in a PV system into a new building with no prior planning. Even when T24 requires PV to be baked into the design before it is permitted. In that case, new service SWBDs often have to get supply-side interconnections and new buildings get conduit running down the outside walls that could have easily been internal. I consider it a failure of the developer not to bring in the PV team for the initial design.

Saying that utilities don't like supply-side interconnections is painting with a very broad brush. Some utilities, particularly small municipal utilities, don't allow supply-side interconnections. But most utilities are fine with it. The big three IOUs in CA that cover 80% of the customers in the state allow supply-side interconnections.

Thank you! I primarily do electrical but have been getting into PV a lot more over the past couple years. I too often see a company like CalSolar or similar come on after the project is in plan check. Since the electric rooms were finalized and gear was already specified it's typical to see them tapping the bus on the supply side to connect. I spoke with an Eaton rep about what was required to provide the tap/lugs and his response seemed to indicate it being better to upsize the bus on the load side and connect there if possible.