“make sure it’s a pure sine wave inverter generator”
I know what you’re referring to. What appliances suffer from “impure” AC.
When solar collector output is “sold” to the power company, it has to be converted to AC and at phase matching that of the power company’s feed. Is that convertor complicated and expensive? Oh, and also metered so they can pay you.
For a grid tied system, there is a controller that matches the phase and controls the voltage headed back to the grid. These are REQUIRED in the design. Most power companies have to sign off on a design with an engineers stamp and then will inspect the install prior to allowing your system to integrate.
Both your local system and the power company track the power exported. Expect to make between zero and a couple dollars a month for your system.