Denmark’s success story in solar district heating, with 2016 having been another record year which almost doubled newly installed collector area to around 500,000 m², showcases the large potential of this type of application across Europe. Cost cuts in the supply chain are key: Two vital factors are fast installation and less hydraulic work on site. The answer by manufacturers to these challenges has been to design large-scale prefabricated collectors. Suppliers of vacuum tube collectors offer modular designs for easy mounting of collectors above 10 m²; large flat plate versions come as one piece and certified by Solar Keymark. The yearly market surveys by German magazine Sonne Wind & Wärme show that the number of certified flat plate collector panels above 10 m² of gross collector area has increased in Europe in recent years. As of 29 March 2017, the magazine’s online collector database listed 62 models from eight brands compared to 20 types of collectors in October 2015.