Decarbonising Italy's energy system with high-resolution thermal demand: Insights from a TRNSYS–H2RES integrated model

Energy planning is essential for analyzing future energy scenarios, yet it remains a complex and data-intensive process, particularly in modeling thermal demand. Simulation tools like TRNSYS provide a robust approach for generating realistic thermal demand projections, which are critical for accurate scenario analysis. This study highlights that achieving decarbonization goals requires electrification, particularly in heating and transport, as electricity-based technologies significantly reduce emissions. However, this transition necessitates substantial investments in renewable energy, with solar photovoltaic and wind power becoming dominant. The H2RES model aligns with Italy’s Long-Term Energy Strategy, projecting that electricity generation must reach 600–700 TWh by 2050, with renewables supplying nearly 100% of demand. A major challenge is managing the variability of solar and wind power to prevent curtailment using flexibility options. Power-to-X technologies, particularly Power-to-Heat, are explored as solutions, with TRNSYS simulations emphasizing the efficiency of heat pumps over conventional heating systems. Full electrification of heating could require an additional 100 GW of heat pump capacity, though integrating biomass could reduce this by 30%. Offshore wind is crucial for winter heating demand. Key challenges include bureaucratic barriers, the pace of renewable expansion, and the development of energy-balancing technologies to ensure a successful transition. • Realistic hourly heating and cooling profiles developed with TRNSYS enhance planning accuracy. • Heat pumps and PtX technologies prove key to Italy’s carbon-neutral 2050 target. • Sustainability concerns shift focus toward clean electrification and wind investments. • Coupling TRNSYS with H2RES sets a new benchmark for long-term, policy-driven energy planning.