This amazing tourist attraction has been insulated using wool and bosses say the scheme has been so successful that fuel bills have plummeted from £400,000 a year.
Historic Scotland bosses have cut the heating bill at Edinburgh Castle by £110,000 a year by using wool as insulation.
The fleece lining for the castle’s historic buildings cut its carbon footprint by 18 per cent.
The castle uses as much energy as 300 homes but its heating bill dropped 27 per cent from £400,000 to £291,000. Read more