I posted this in another thread but it seems to be applicable here too.
When the question about supply side interconnections was submitted to the NFPA in 2013 for guidance here was the response:
Q:
I and the PV industry need some further guidance on how we should be handling the "feeder" circuit for the Supply Side (of the service disconnect) Connection of a Photovoltaic Power system as allowed by 705.12(A), and 230.82(6). It is not clear also why 230.2(5) mentions additional "services" for parallel power production systems, which seems to indicate that a utility interactive PV system could be considered being connected by a service.
A:
Section 230.2(A)(5) retained the “parallel power production systems” as a special condition for an additional service from the 1984 NEC 230-2 exception No. 2. Based on the definition of a service at that time being an “electric supply system” the substantiation which stated “The addition to Exception No. 2 is necessary to permit a solar photovoltaic, wind or other electric power production source to be installed in addition to a (utility) service in a building or other structure” made sense as an additional “electric supply system.” However, once the service was redefined and specified as only being supplied by a utility other solar photovoltaic, wind or other electric power production sources no longer fit the description and more specifically the service cannot “supply” them as 230.2(A) permits.
A service can only be supplied by the serving utility. If electric energy is supplied by other than the serving utility, the supplied conductors and equipment are considered feeders, not a service. See the definition of service in Article 100. The understanding of other electric supply systems being considered a service changed when the definition of service changed during the A98 code cycle. ROC A98 Comment 1-199 Log # 2472 on Proposal 1-132 was accepted and specified that the term “serving utility” not an “electric supply system” be the language used to define a service.
This indicates to me that in 2013 the NFPA considered supply side interconnections of PV systems to be feeders and not services. The addition of 705.31 in 2014 strengthens this determination. It still looks like a service entrance to me so that's how I design them and the NEC does not say I can't do it that way.