Fuel Switching Strategies for Decarbonising the Glass Industry Using Renewable Energy and Hydrogen-Based Solutions

This study addresses the decarbonisation of the glass industry from an integrated energy system perspective, analysing the role of renewable electricity, electrification, and hydrogen in meeting the high and continuous thermal demands of glass melting. While direct electrification emerges as the most efficient option from a purely energetic standpoint, the intermittency of renewable generation poses significant challenges to continuous furnace operation, highlighting a potential complementary role for hydrogen. The general framework is applied to a representative oxyfuel glass furnace, using a mixed-integer linear programming (MILP) optimisation that minimises melting costs under variable solar and wind generation, battery storage, and hydrogen production and storage. Results show that high levels of furnace electrification combined with wind-dominated renewable supply yields the lowest decarbonisation costs, which can become negative under favourable conditions. However, battery and hydrogen integration extend achievable emission reductions from around 50% to 80%, with hydrogen proving particularly relevant for enabling continuous operation under limited renewable availability. Sensitivity analysis identifies energy and carbon price regimes in which storage-based solutions become cost-effective, confirming that hydrogen, while less efficient than direct electrification, can play a strategic role in deep decarbonisation by supporting continuous industrial operation. The proposed framework is transferable to other hard-to-abate industrial sectors facing similar constraints.