The 80c per kwh seems very high. But strange as it may seem, here in the Peoples Republic of NJ, you get paid for the total amount of electricity the solar array generates, not just the excess amount. It's not a direct payment per kwh though. That would be too easy.
The actual story goes something like this. Utilities are being forced by law to supply increasing amounts of renewable energy. They can meet that number through a variety of ways. They could buy it from wind sources on the grid, for example. But they can also buy certifcates from folks who generate solar at their homes or businesses. That certificate counts just like if they had bought energy from company X's windmill on the wholesale grid somewhere.
Every time the homeowner solar array generates a certain amount of KWH of energy, the homeowner gets one certificate. Then it gets more complicated. They have some kind of auction system that determines how much those certifcates are worth and how much your power company will pay for it. The amount has flucutated widely, for factors I don't understand. But in recent years the typical 8KW array could generate a couplel thousand dollars a year back to the homeowner.
Oh, and I think they will also actually pay you an additional small amount for any net amount you put into the grid once a year too.