Yeah, I need to add one of these too, but I'm not sure how to integrate one properly with a Sol-Ark 15k.
I got most of the way through signing up for SRECTrade, and entered that I had no revenue grade meter, and it disqualified me for registering for MD SRECs until I have one. But it offered me the ability to sign up in PA. I haven't been able to figure out yet whether that's a legitimate option, but it'd be nice if I could just read off the production value and sell them in PA for less.