Just to be clear here… I agree that you can take the approach that $11,000.00 up-front does indeed pre-pay your electricity costs. Basically you spend 11k, put solar panels on your roof, supply power back into the grid, receive a subsidy for your feed-in and end up basically stabilising your power costs over a 10 year period.
Commercially this was one point that got me to buy-into solar.
But it do no not make this technology a winner. Nor does it make it “green”.