How are you all finding this energy rising?

[A_Camera]

Been looking into it as you suggested.
The company who fitted mum's went bust years ago. It's actually on of those installs where the company rents your roof from you.
Will have do do some deeper digging and find out who inherited the bust companies contract.

As for the father in law he bought his outright at the high rate Feed In Tarrif (FIT). It still makes enough to cover the initial cost and give about £100 per yr in pocket. His quote is.....
'It's never been anywhere near what the salesman quoted but it will do'.

I have never heard of "roof renting" contracts, maybe they exist in Sweden as well, but in that case the roof owner gets paid for the use of the roof. Just like if you want to rent a room in my house, you have to pay a rent. The only ones who don't pay rent for using my roof are the birds and the bugs...

As for your father in law, even he should check the contract, because if it is true, and the contracts are similar to what we have, then he should have a production warranty also. On the other hand, the payback can't really be calculated in cash, because that depends on the price per kWh, which as we can see specially now, nobody really can predict. However, the produced power can be anticipated with quite good accuracy. Anyway, what the salesman is promising, or have promised, is pretty irrelevant unless it is printed on the paper he signed.