No, that's not it. You're still buying and selling electricity to and from your utility company. The 12¢/kWh that you're paying to Tesla is the rental on the so

No, that's not it. You're still buying and selling electricity to and from your utility company. The 12¢/kWh that you're paying to Tesla is the rental on the solar panels. Why it seems confusing is that you're paying based on how much electricity is produced, but it's still simply a rental. If you sell your electricity to the utility for 16¢/kWh, and are paying Tesla 12¢/kWh, you will make 4¢/kWh. Which is not a lot, but it's with no upfront costs.