(ie the most difficult 15mins in the year is due to air conditioning)
I guess that depends on where you live. I know the thread is titled with the word Arizona in it but the concept will spread to other states.
fwiw in my case my highest bill comes from heating not cooling though both are done by a heat pump. I just don't use heat as many months as I use cooling so my AC unit is designed for best efficiency in warmer weather and I put up with the higher heating costs the one or two months of the year it gets really cold.
also even without solar panels I pay a "service charge" that puts a minimum on my electric bill, it's up to $13 per month now and seems to rise at least once per year.
If they added an additional fee to allow back feed from solar panels it would stretch the payback on buying solar PV or negate the possibility of payback.
All said and done I average closer to the top end of triple digits kwh/month with a minimum above 500 and a max around 1200. Low enough that my solar instillation would be small and a fixed fee would be an issue. I'd rather see a per kwh fee so small systems wouldn't be discouraged, using multiple brackets of system sizes with a separate fee in each bracket, or just have systems below a certain size be exempted entirely and save the fee for larger residential systems.