Re: Solar panels

On 5/31/2024 2:15 PM, boB wrote:

72 cells is a common PV module (panel) configuration.
 So is 60 cells.
 An MPPT charger is usually a buck converter so that's how it gets
there.  A nominal 48V PV array will need to have a higher Vmp than the
battery voltage to charge that battery bank.

Not intended to "charge" the battery but, rather, for the battery
to look like an ideal capacitor.
I can "charge" it from the mains, after hours (as well as supplement
any load that I feel needs to be powered in the absence of sunlight)

Sounds like Kevin knows his stuff regarding this and you aren't far
off, if at all.
 Rapid Shutdown requires the array at the string (HV) inverter or
charge controller input to be at or below 30V in 30 seconds after its
clear to go signal is removed.  At least those who are being inspected
to NEC.

If I can let the array look like a single 48V panel (a bunch of them,
each contributing some amount of current to a single/shared load),
I figure it simplifies the deployment by distributing the electronics
among multiple relatively low power (300-400W) sources.
Otherwise, you have to reengineer a solution for each deployment -- 3KW,
5KW, 6KW, etc. each requiring a bigger "power supply" (to produce the
48V from the AC generated by microinverters or a string inverter)
E.g., I can use a single panel, by itself -- as long as my solar load
is ~300W (supplementing with mains-derived power if it exceeds this
on the short term or if the sun hides)