I don't really understand this. I just looked into moving onto EV rates for PG&E and the super cheap "off peak" hours start at midnight and run through the nigh

I don't really understand this. I just looked into moving onto EV rates for PG&E and the super cheap "off peak" hours start at midnight and run through the night. If solar is causing issues with overcapacity during the day why are they charging me peak rates starting at 3pm?