Renotec, AGT and law firm Schoups have teamed up to investigate the potential of heat recovery and storage in our sewer system. It has huge potential, as the network of existing sewers is very large. In Brussels alone, there are 2000 km of sewers (which is more than the distance from Brussels to Milan and back). If the heat from waste water in these sewers can be used as a low-temperature source, and the sewers are perhaps even used to store heat, this could contribute in a cost-efficient way to making Flanders a smart energy region.