If Duke pays for power at the same rates that they charge*, the homeowner would probably come out ahead. Duke's rates for central NC look something like:
36 c/kWh for critical peak times (ie when you'd be sending power back to the grid)
19 c/kWh on-peak (midday in the cooling season, morning in the heating season)
10 c/kWh off-peak
7 c/kWh discount (not sure when the discount is, likely in the middle of the night)
Presuming that you can set your wall box to make sure you always have X miles of charge in hand, you can buy a kilowatt-hour at 7 cents and sell it back at 19 cents. If there's a crisis, which is when people in this program would be tapped, you'd really make bank. The only caveat is that you can't sell more peak kWh than you consume in a year.
Duke's rate schedule with emergency rates for the gory details if you care to look closer:
https://desitecoreprod-cd.azureedge...tes/electric-nc/r4-nc-schedules-r-tou-cpp.pdf
* Duke does do net-metering for solar/wind power including peak time/off-peak time rate differences, so it seems likely that they can manage this as well. No guarantees though...