Wastewater has a primary energy factor of 0. In addition, there is the primary energy factor of the auxiliary energy for the heat pump. After the heat pump, the primary energy factor of the wastewater heat is 0.4 to 0.45. All German energy efficiency standards can thus also be met for buildings with energy from wastewater. Energy from wastewater is even equal to or superior to the district heating option, which is often attractive in terms of primary energy.
