This reminded me of a casual conversation with an acquaintance about how they sold their home, with (older) solar panels and had some sort of agreement where th

This reminded me of a casual conversation with an acquaintance about how they sold their home, with (older) solar panels and had some sort of agreement where they still got paid for the money generated by the panels. It sounded odd, as in; who would buy a house where something on the roof was generating income for the previous owner? - Wouldn't you (the buyer) just buy them out? No idea how this was structured - anyone have any background?