Inverters won't work.
Well, it will work for a couple of hours, then you'll see a drop off in power, and the ballasts will shut down.
You'd need an endless supply of fully charged batteries, and someone to switch them every couple hours.
OK for an emergency back up, for a couple hours, but not to run your grow continuously.
Small generators will have the same problem, only they will run out of gas even faster.
Don't waste your money.