The report illustrates some research activities aimed at the development and dissemination of useful tools for the promotion of waste heat recovery from industrial plants, so as to use it in district heating networks, and an environmental sustainability analysis conducted on a sample of district heating networks.

A web application for the analysis of the social-economic and financial sustainability of waste heat recovery projects has been implemented. Validated on model cases, the application enables in a simple way a sensitivity analysis of the results with respect to the various relevant parameters, and is freely usable on the web by technical staff of district heating networks, ESCOs, industrial operators, and institutional decision makers.
In an attempt to remedy the reduced knowledge of the costs of installing and operating waste heat recovery systems, a dedicated questionnaire has been developed that can be used by the relevant authorities as an aid for data collection from industry stakeholders.
With the aim of consolidating the quantity and temperature values of waste heat recoverable from plants in the various industrial sectors, a selective update of the information available in the literature was carried out with the collaboration of Politecnico di Milano, broadening the field of interest to low-temperature waste heat sources with a view to preferential use for fourth-generation low-temperature district heating networks in connection with heat pumps. In this framework, a number of numerical simulations were also conducted to evaluate sizing and effects of thermal storage, components that can deal with discontinuity of waste heat supply and decoupling with demand.
The collaboration with Politecnico di Milano also allowed the collection of geolocation data of industrial plants registered in the ETS register, waste-to-energy plants, urban purifiers and companies that submit Integrated Environmental Authorizations to Regione Lombardia. From the latter data, the relevance of the potential contribution of waste heat from smaller companies could be inferred.
Sample environmental sustainability analysis of district heating networks confirmed the general suitability of district heating, but showed that there is not always a correlation between primary energy savings and CO2eq emissions in the results. In the cases under review, the contradiction is mainly due to the
coefficients assigned to MSW, which suggests their revision at the regulatory and legislative level.