The energy price assessment performed in the document “D4.1 – Energy Price Assessment" provides a comprehensive review of the main heat production systems and primary energy sources associated with District Heating systems in Europe. Geothermal heat flow density in Europe. EC 2012. © EC, 2012. District heating (DH) systems are one of the most energy efficient heating systems in urban environments and they are also key systems in the de-carbonization of heating energy in European Cities. Renewable and waste heat sources are foreseen at the same time as de-carbonized heat sources and the way to guarantee competitive energy costs with limited influence of fossil fuel supply price volatility. To achieve this, conversion of DHs is needed. RELaTED will [...]