Understood. The thing I'm mindful of is that that single power feed isn't powering a single cabinet in the hybrid areas, it's powering a whole bunch of them. That feed goes onto a power injector which then fires power down coax to the rest of the cabinets in the cascade. That cabinet also has a UPS and battery backup to keep the MSAN sitting next to it alive in case of loss of mains power.
The FTTP areas, though, have a power cabinet which has the UPS, etc, and feeds the OLT in the cabinet neighbouring it. I'm not sure how much juice those OLTs draw.
I happily defer to your knowledge on this one, though.