Energy dialogue between district heating networks

This study evaluates the RA project, an innovative district heating system in Udine, Italy, which harnesses waste heat from a steelmaker, in alignment with the European Road Map 2050. The project is notable for its recovery and utilization of thermal energy, thereby contributing to improved energy efficiency and environmental sustainability. While the system itself is site-specific, the underlying principles and methodologies are broadly applicable to comparable projects. A key feature of this project is a patented continuous heat recovery system that captures heat from molten slag. The recovered thermal energy is distributed through a network to supply heat to various consumers. Three main user groups have been identified, each with complementary energy demand profiles, to optimize the use of recovered energy from the steel plant: (i) an industrial urban system consisting of direct wintertime urban consumers with predominantly daytime energy needs; (ii) a winter smart grid leveraging nighttime heat production for daytime use; and (iii) a summer smart grid converting excess heat into cooling energy. Three strategic scenarios were assessed, involving the progressive aggregation of the three user groups. For the energy, environmental, and economic assessments of these groups, as well as for evaluating the economic implications for the steel plant's feasibility and environmental performance, the “Terpsichore Method” was applied. This method enables a comprehensive evaluation of benefits, including reduced operating costs, fossil fuel consumption, and CO 2 emissions. Finally, a financial evaluation of three strategic scenarios confirms the feasibility and scalability of the RA projects as a replicable model for industrial waste heat recovery in district heating systems. • Innovative approach to recovering waste heat from steel production processes. • Three user groups for optimizing heat reuse via complementary energy demands. • 86 % utilization of available thermal energy from the steel plant achieved. • Terpsichore Method applied for integrated energy and impact assessment. • Highlights territorial synergies for efficient industrial heat recovery.