Clean Energy Charging engages only where you spend the most time and regularly charge your iPhone for long periods of time, such as your home and place of work. The feature doesn't engage if your charging habits are variable or you're in a new location, such as when you travel.
Welcome to the California Independent System Operator (ISO). We manage the flow of electricity, operate a competitive wholesale energy market, and oversee transmission planning.
www.caiso.com
CA use of renewables is readily available and the phone will charge even when its at 2% during the period CA ask's people to preserve power due to it being less clean. I've never seen the phone actually reject a charge.
I don't want my phone downloading grid data and telling me when I can charge my phone or not. The electrical grid should work to serve me, not the other way around.