A Scenario-Based Assessment of Competing Technologies for Industrial Decarbonization

Industrial process heat decarbonization requires combinations of energy efficiency measures, energy-conversion technologies, renewable heat, and sustainable fuels. This study investigates the role of solar thermal (ST) within such integrated decarbonization pathways. A screening framework combining Pinch Analysis, life-cycle assessment, techno-economic evaluation, and multi-objective optimization is applied to five industrial thermal-demand archetypes under five European regional scenarios. Pareto-optimal configurations of direct heat recovery, heat pumps, ST, biomass, and residual conventional utilities are evaluated. The role of ST is characterized by its integration temperature, entry point along the decarbonization pathway, solar fraction, and required collector area. Results show that ST deployment does not follow a simple regional irradiation gradient. Process thermodynamics largely determines the duties accessible to ST, while regional conditions influence when ST becomes competitive and the contribution it achieves. In most scenarios, ST acts as a complementary heat source, although substantially larger contributions emerge for selected process–region combinations. Collector-area constraints further reduce the practical feasibility of some otherwise Pareto-optimal solutions. The results demonstrate the value of considering process thermodynamics, competing technologies, regional conditions, and spatial feasibility jointly when screening industrial ST opportunities.