It’s a grid tie system, and we get one for one credit.

So during the summer we rack up credits and have a negative bill (power company owes us money) then use it all up and a little more during winter.

Wow that's great, you're getting treated like royalty!

Not at all. Basically everywhere had a one for one feed in tariff when residential solar was new in their area. Friends in Australia are still grandfathered into that (they got a 1.3kw system in like 1990)

In Germany for a long time the law was three to one for green energy you generated and gave to the grid. Ie you put in 1kwh they credit you 3.

Even today basically every location can grid tie and get a feed in tariff, the ratio just depends on how many people in your area got residential solar before you.