What is this?

I got this in the mail and am confused on it? I only have one electric company in my area as it is a co-op. Is this a electric company or just some specific to owning solar? I'm still new to the solar thing.

I got this in the mail and am confused on it? I only have one electric company in my area as it is a co-op. Is this a electric company or just some specific to owning solar? I'm still new to the solar thing.