As a Massachusetts resident with solar panels I can tell you that this is a useful service. In this state you do not get paid for the over production and instead it just accumulates in your account. I currently have a $500 credit with the electric company and no good way to cash out.

There is a mechanism in place to give someone else your extra credit but then you need to figure out how to charge them by looking at your bill every month. There is also a requirement that the person you transfer to must be in the same "ISO-NE load zone" and I haven't figure out what that means yet. It probably means that my neighbors are ok, but my co-workers might not be an option.

I don't know know how they set their rates, but I would be happy to sell people electricity at 75% of what they pay the power company since I am not doing anything with my extra as it is.

To answer the power or money question: This is just a money transfer. It is similar to the way anyone can purchase renewable energy for a 10% premium. They don't send you different electrons, it just gets paid differently.