If other ratepayers aren't picking up the tab, presumably the power company figures the use of smart chargers will save them money through reducing max. demand.
I read some stuff about excess capacity at night that is sometimes sold wholesale to other grid partners at a loss. Controlling when an EV charged, even off-peak, could offset that.
I received my free unit, but they haven't taken control, yet. I am charging as before.
When the wind's cranking or the sun's beating down and the load isn't there, the utilities often have to pay someone to take the energy (or ask the generator if they would mind, pretty please, curtailing their output. The generator, who makes money on production, is unlikely to want to do that without some incentive). I've read one report of an evening when the wind turbines in the Columbia Gorge were maxing out and the demand was low, and the dams were near full but had to be kept generating, as they couldn't open the spillways because the flow would have killed lots of salmon fingerlings at that time of year. The utility had to pay $0.64/kWh to get someone to use it - this is what's known as negative pricing. Needless to say, the utilities aren't happy when they have to do this, which is why cheap storage is the holy grail to make the grid happy with variable renewables. Batteries are still too expensive for mass storage, so that leaves pumped storage, compressed air in salt caverns, H2 or something else as yet unknown, assuming that PEV owners can't be convinced to let their car batteries be used both ways (V2G).