As to night charging tarrifs
We used to have a day/night electricity tariff for our home. When the kids were little it just about made sense. We saved money and used electricity at night when it was in surplus. But not for long. The problem being that the night cost was cheap, but the day time cost is significantly more than on a normal tariff. So much so that it overwhelms the night time savings. For the electricity companies encouraging more over-night use ought to be a good idea, but apparently they don't see it that way.