pv_pablo

Arizona specific: APS has a dedicated EV off-peak window under their EV rate plan (AC-11) that's separate from the solar export program. Worth calling APS to ask specifically about stacking the solar NEM credit with the EV off-peak rate. I've had customers significantly improve their payback by optimizing these two programs together.

Unirac SFM Infinity is what I spec on commercial jobs — excellent engineering and very strong pan-tilt options. For residential DIY, Ironridge XR100 is the better choice: better span table tools, wider availability at distributors, stronger DIY community documentation online. Both are good; Ironridge wins on the DIY support ecosystem.

Adding to the derating factors: soiling in Arizona adds 5–8% loss in summer on systems without regular cleaning. July and August without rain means 3 weeks of accumulated dust on panels rated at 400W STC producing closer to 340W. I use 0.75 as my efficiency factor on Arizona residential installs, not 0.8. Small but meaningful on a tight build budget.