Question for Houston area homeowners with solar panels

I just got solar panels put in. I currently have a solar buyback plan with Reliant, but I got to wondering if I could switch to a free nights plan and then recharge the battery from the grid for free?

Does Centerpoint pay you for your extra generation or does it get paid through someone like Reliant? If I switched out of the solar buyback plan would I stop getting payments for extra power generation?