In the UK it's quite a common setup that you don't buy the panels outright, you sign a contract with a 3rd party company that installs the panels on your house and maintains them, but they own the panels, you can just use whatever electricity they produce and any surplus goes to the company owning the panels. The problem is that a lot of these companies went bust when the government ended the electricity export subsidy, and in most cases these panels were then transferred to a larger provider that honours the original contract but on the sale of the house they won't transfer it to the new owner - the only option is for the new owner to buy them outright. And because they rarely look at them in terms of current market value, they will quote you whatever the panels were brand new - which yes, absolutely can be in the £15-20k range, which is crazy by any measure, and you end up in this stupid situation. Usually the best option is actually to remove them instead, but as per contract - you are liable for the cost of doing so, which ends up costing few grand anyway, once you factor in scaffolding and labour and recycling and everything else. And so it's now a burden when it comes to selling the house.