Marstal solar heating plant in Aeroe, a renewable energy island south of Denmark. It’s among the largest in the world with more than 33000 m2 covered in solar panels, producing heat for 1560 customers, who are also owners of the cooperative station. When the heating requirement cannot be covered by the sun, a wood pellet boiler will supplement the requirement. Two Danish islands, Samsoe and Aeroe, became the first of Denmark's official renewable energy islands.