Does this mean the phone only charges during the day? It won't charge at night when solar and wind are least effective and fossil fuel power is used nearly exclusively?

If that's true, it would be most inconvenient for me as I only charge my phone at night, while I'm sleeping. Seems simple enough to disable but to change the charging behavior on an update might be a bit of a shock if you expect your phone to charge at night and it didn't. I'd likely replace my charger first, which is wasteful, before checking if my phone was just "being green."