Sorry but this is wrong. 690 requires separate AC and DC grounding electrode systems to be bonded together (even if 250 doesn't).
First lets separate the grounding requirements between Equipment grounding and Grounding electrodes, and AC and DC systems, While 690 leaves much to desire in its wording it still clearly refers to 250 in most of its instructions as to how to ground the equipment and or the structure.
First the requirements in 690 are separated in two parts 690.43 thru 690.46 are the requirements for equipment grounding (EGC's) and 690.47 thru 690.50 are for grounding electrode requirements (GEC or GES) with some requirements for Equipment bonding and EGC's also put in it.
690.43 Equipment Grounding. Exposed non?current carrying metal parts of module frames, equipment, and conductor enclosures shall be grounded in accordance with
250.134 or 250.136(A) regardless of voltage. An equipment grounding conductor between a PV array and other equipment shall be required in accordance with 250.110.
Devices listed and identified for grounding the metallic frames of PV modules shall be permitted to bond the exposed metallic frames of PV modules to grounded mounting
structures. Devices identified and listed for bonding the metallic frames of PV modules shall be permitted to bond the exposed metallic frames of PV modules to the metallic
frames of adjacent PV modules. Equipment grounding conductors for the PV array and structure (where installed) shall be contained within the
same raceway or cable, or otherwise run with the PV array circuit conductors when those circuit conductors leave the vicinity of the PV array.
The above in red is for EGC's and is not repeated for GEC's anywhere in the code, this is the same for separate structures in 250 as each building or structure served is required to have it own GES and there was never a requirement to run a GEC between separate structures and for good reason, doing so does not provide any additional protection from lightning or any other condition that the EGC would already provide as it is meant to only protect the structure it serves.
690.47(D) Additional Electrodes for Array Grounding.
Grounding electrodes shall be installed in accordance with
250.52 at the location of all ground- and pole-mounted
photovoltaic arrays and as close as practicable to the location
of roof-mounted photovoltaic arrays. The electrodes
shall be connected directly to the array frame(s) or structure.
The dc grounding electrode conductor shall be sized
according to 250.166. Additional electrodes are not permitted
to be used as a substitute for equipment bonding or
equipment grounding conductor requirements.
The above in red further supports the requirement to have a grounding electrode system at the location of the array even when 250 kind of already states this for separate structures, the last statement of the electrodes not being allow to be used in lew of an EGC or bonding is the same as stated in 250 as the Earth can not be used for a fault clearing path as it is too high of resistance to do so.
Sorry this is also wrong. An array EGC should be brought directly to the inverter (or GFDI device, if it is separate). Or at least it should be tied more directly to the DC GES, not the AC GES (even though they are bonded together).
Since there are many methods of design 690.47 gives us many ways to apply the requirements in (1) thru (8) with (1) basically stating that if there is both an AC system and a DC system that the two shall be bonded together (this is a bonding conductor not a grounding electrode conductor, the grounding electrodes were taken care of back at the PV array) it requires the DC system to be bonded to the AC system (yes that is what 690.47(1) states) (2) of 690.47 tells us even to size it per the requirements of 690.45 which is for the EGC not a GEC (3) allows us to use a common conductor for both systems more then likely when the inverter is mounted on the array in which (6) seems to confirm this as it allows a common electrode system where the inverter is mounted out on the array and the output conductors are brought to the house will only require a EGC, (7) is only to remind us that GEC's are to be sized to 250.66 where you have a GES at the array or at the house where a GES is required or as in (8) where we can use the premises
grounding electrode system when utility-interactive inverters are used.
The parts that I had to think about is the requirement of additional grounding electrode systems when a roof top array is installed but then I remember the requirements of 800 for antennas where if the antenna will require over 20' of grounding conductor to reach the service electrodes it is required to install a separate grounding electrode then bond it back to the service electrodes.
The problem with understanding grounding and bonding requirements is we tend to cross the two and apply the wrong term to the wrong requirements, bonding is more part of equipment bonding as in EGC as in this case it even points to use the sizing for EGCs in the requirements.
The other point is to understand that lightning will not travel very far on most conductors sized per 250.66, it is a high frequency event and impedances of our round conductors will be very high which will limit the amount of current on the conductors if over a certain length, most of the NEC doesn't seem to follow this line of thought, except in article 800 on antenna requirements and in 690 where it requires that the GES to be as close as it can to the PV array, I'm very surprised that 690 also doesn't mention the requirement of bonding the two GES where a roof top PV array is used on a house with a GES at the service even when 250 will require it, this has to be done as if lightning were to strike the PV array there will be a difference of potential between the two GES systems, again another reason that there is no requirement for a GEC to be brought to the house from an out building or structure is because the differance of potential is to far apart between the two systems, on the same building this could be more of a problem.