This study evaluates the economic feasibility of flexible, renewable ammonia production in Italy through a comprehensive sensitivity analysis of the levelized cost of ammonia (LCOA). Ammonia is produced through Haber–Bosch synthesis from green hydrogen and nitrogen coming from alkaline electrolysis and cryogenic air separation, respectively. The analysis examines the impact of key parameters such as renewable source peak power, Haber–Bosch reactor flexibility, energy mix, electrochemical and hydrogen storage, on the final production cost. The location considered for the PV and wind power output is Southern Italy. The results show that a wind-driven system with minimal battery storage and a flexibility factor (ratio between the minimum operating capacity and the nominal capacity of the plant) of 20% offers the most cost-effective solution, but production is scaled down to 64 tpd. With the 2030 cost structure, battery storage offers better integration with wind systems and flexible operation, even at low levels of turndown. For different combinations of process design choices and flexibility, the optimal LCOA for a green ammonia production is approximately 0.59 USD/kgNH₃ in 2050. This cost of production could be competitive with grey ammonia, provided that a carbon emission allowance of USD 0.12/kgCO₂ is applied.

Carbon capture could support deep decarbonisation only if the energy required for separation, regeneration, compression and refrigeration is supplied with low lifecycle emissions. This review approaches low-carbon and renewable energy integration into carbon-capture processes from the point of view of the technologies, integration problems and energy vectors encountered when entering the capture boundary: renewable heat (RH-CC), renewable electricity (RE-CC) and renewable or recovered cryogenic energy (CR-CC). For RH-CC, indirect solar heat (ISH) is the most retrofit-compatible route, whereas thermal or solvent storage improves flexibility, and direct solar solvent regeneration (DSSR) offers greater process intensification but remains largely model-based. For RE-CC, direct electric heating is the simplest option but retains the intrinsic regeneration duty. High-temperature heat pumps (HTHPs) and mechanical vapour recompression (MVR) show the strongest near-term potential through heat recovery and upgrading, whereas electrochemically and mechanically assisted pathways must be scaled up and require complete energy balances. CR-CC can combine renewable-powered refrigeration, recovered cold energy and liquid–air energy storage (LAES) in high-efficiency multi-purpose solutions, although multi-product boundaries complicate comparison. Across all pathways, promising solutions of low-carbon energy penetration and high separation performance have been identified and classified; although full development depends on resource quality, temporal matching, host–process integration and electricity carbon intensity in site-specific solutions.