Thanks to offshore wind energy, the Royal Family in Great Britain can rejoice: Their annual income is higher than ever.
The rules of a modern monarchy are complicated. In Great Britain, the Crown Estate is owned by the British Crown. Like the crown jewels, it belongs to the monarch in his/her capacity as head of state, but it's not his/her private property. The monarch can neither sell the Crown property him-/herself nor take the proceeds personally, because the Crown Estate Commissioners are in charge of the administration and are accountable to Parliament.
Thus the royal family is ...