It says "Pay for what you generate"
Do they mean "Get paid for what you generate"? Or am I missing something really fundamental here?
If you choose to "subscribe," you are committing to paying Tesla 10-13¢ for every kWh you generate. You are then (if you're in a state with net metering) selling it to the state for a profit.
In CA, the average cost of electricity is apparently about 16¢/kWh. So you're making a profit of 3-6¢/kWh.
The incentive to you is that it's free to install, and has no commitment apart from a fee of $1500 if you want to remove the system. The incentive to Tesla is that they are selling electricity to the state for full price, minus 3-6¢/kWh to you for renting your roof.
As you say, Tesla is reframing the argument from renting your roof --> you selling clean electricity to the grid to make it more palatable but I don't see a problem with that.
(You buying power can be thought of as a sunk cost, as this isn't changing it at all (unless you are also storing power), so it can be removed from the question.)
At the same time that you are selling power to the utility company, you are also paying Tesla 10-13¢ for every kWh you generate.
If you are able to sell at a higher rate than that, you keep the extra.
If you "subscribe", you "rent" solar panels which Tesla will install, and you will use them to generate electricity which you use. You pay for the electricity that is generated, in place of paying a rental fee for the hardware.
It seems unusual, but it's a bit like renting a truck for a very low price (i.e. $20) but then you pay $1.50 for every mile you drive. It's still a little hard for me to wrap my head around, though!
I guess the idea is that since it's your property you're the one generating energy, albeit with their equipment.
They could word that better.
“We sell you the electricity generated that you use at a discounted rate compared to utilities”
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.