Only households can access the free electricity window. If you're not on a free plan you can get reduced rates during the solar peak window but business accounts aren't allowed to access those either.
plug my car in, it might be full, it might be empty, either way its racking up the charge cycles for no direct benefit for me.
Batteries on a house makes a better sell for customers, and also targets the problem of both over supply and over consumption at source.
Even most residential batts that get plugged in when they get home typically have SOC >40% (depending on jurisidiction).
A smaller version of these things: https://sandtoft.org/wp/
Some people drive as if they're in dodgem cars as it is.
It already exists and works so, not that crazy