NEC or Not

[beanland]

The 2014 NEC Handbook defines a PV interactive system as "A solar PV system that operates in parallel with and may deliver power to an electrical production and distribution network." Under this definition, a large PV plant that is built to put power on the utility grid could be an "interactive system", since even a large utility-scale PV system consumes power when the sun is down, it is a both a load and a generator. It is also interactive in that it reacts to events on the grid. (Even a coal or hydro power plant is a load when not generating.)

However, 90.2(B)(5) states that the NEC has no jurisdiction over utility power plants; and a utility is generally defined as an entity that performs utility functions such as generating, transmitting and delivering power to consumers; and it is widely accepted that power plants and substations are covered by the NESC, not the NEC.

So, what can I point to the NEC that unequivocally shows that a PV power plant that is "utility interactive", including the PV modules, DC wiring, inverters, AC wiring, transformers, etc. is not under NEC jurisdiction?

 

[GoldDigger]

...unequivocally shows that a PV power plant ... is not under NEC jurisdiction?

You want to point to something in the NEC that says unequivocally that a utility interactive PV system is NOT under the NEC?
I do not see anything to suggest that, and if it were true then the vast number of words in the NEC that purport to regulate utility interactive PV systems would seem to be pointless.

At some point there may be a dividing line between a residential or commercial scale PV system using Grid Tie Inverters (GTIs) and a multi-megawatt scale commercial facility, but to the extent that the system is not operated by a utility, I see them all as still regulated by the NEC.
Now other entities, including governmental such as the TVA, may not be privately owned publicly regulated utilities, and so that wording {"an entity that performs utility functions ") in the NEC may be considered necessary to exclude them, but I just do not see that exclusion applying to a PV plant of any size that is not operated by a utility or quasi-utility.

Also, an entity that provides only one of the enumerated functions without any of the others may well not be a utility either.

 

[beanland]

What is a utility?

What is a utility?

So, if I am a private for-profit corporation and I build a 500MW (that is mega) PV power plant that connects to a utility transmission system at 500kV, where is the line drawn? By my being a corporation, I am regulated by the FTC, SEC and others. By being a power generator, I am regulated by the FERC, NERC and others. But, I am not regulated by the PUC. (I could even be a PUD, cooperative, or municipal utility that is not regulated by the PUC.) Am I a utility? How is it determined?

So, what part of my power plant falls under NEC jurisdiction and requires permits and AHJ inspections and what portion of my power plant falls under NESC? Is it the module and array? Is it the DC up to the inverter? Is it the output of the inverter at 830VAC? Does it cover the GSU that steps the voltage from 830VAC to 35kV? Is it the collection system operating at 35kV? Is it the power station that converts 35kV to 500kV? Is it the point where my 500kV line lands at a facility owned by a "utility"?

 

[GoldDigger]

My initial reaction would be that all of it is covered by the NEC.
But let's continue the discussion.

 

[jaggedben]

This article seems relevant. It seems to imply, though, that you are not a utility.

...Am I a utility? How is it determined?

My guess is that it defined by the laws of the state you are in. Just a guess. I gather you've noticed it's not defined in the NEC.

Or to put it another way, you'll probably need a lawyer.

So, what part of my power plant falls under NEC jurisdiction and requires permits and AHJ inspections and what portion of my power plant falls under NESC? Is it the module and array? Is it the DC up to the inverter? Is it the output of the inverter at 830VAC? Does it cover the GSU that steps the voltage from 830VAC to 35kV? Is it the collection system operating at 35kV? Is it the power station that converts 35kV to 500kV? Is it the point where my 500kV line lands at a facility owned by a "utility"?

That last one. IOW, wherever the ownership of the equipment or conductors changes. It is not a technical question.

Looking at Article 90 the only section I see being pertinent is 90.1(B)(4). You probably have to get yourself designated as a utility if you want to avoid the NEC. Good luck.

 

[beanland]

Wind and Non Trivial

Wind and Non Trivial

I have seen this same issue arise in the inspection and permitting jurisdiction for large wind projects; some say it is electrical so it is covered by NEC, others say it is a power plant operated by a "utility" so it is under the NESC.

If nothing else, clarification is needed in the 690 wording so that "utility interactive" and the nature of the installation is more clearly delineated. I totally agree that a PV system on a home or business should be under NEC. I also think that a moderate sized PV installation that is owned and operated by a non-utility should be under the NEC. But, even though we use the same equipment at 500kW as we use at 500MW, we need to clarify where code applies. Perhaps we need a definition of "electric utility" in the NEC: "A business entity, corporation, company, municipality, or other organization generally recognized as engaging in the generation, storage, transmission, transformation, distribution and/or sale of electric power and energy; which is supervised and governed by an authorized regulatory body such as utilities commission, NERC, FERC, cooperative members, city, state, or county."