Solar-Powered Electrification and Hydrogen Integration for Decarbonising the Glass Industry

Deeper penetration of renewable energy is essential for decarbonising the glass industry, but balancing its intermittent nature with the sector’s continuous high process heat demand remains challenging. Hybrid glass furnaces offer a promising solution by combining direct electrification with fuel switching to green hydrogen. This paper quantifies the viability of increased boosting levels in hybrid furnaces, identifying threshold conditions for profitability and sustainability at an electricity-to-natural-gas price ratio of 1.5 and an electricity emissions factor of 0.3 tCO2/MWh. Subsequently, it investigates the economic and environmental impact of varying solar energy availability on decarbonising the energy supply of a representative 300 t/d oxyfuel container glass furnace equipped with solar plants and electrolysers of varying sizes. In the direct integration configuration, average melting cost savings and emission reductions reach 28.1%, and 18.8% for a 1:1 ratio between nominal furnace energy demand and solar generation. In a hydrogen integration configuration, average melting cost savings and emission reductions rise to 42.5% and 48.0%, with peak cost savings of 46.5%. Full energy self-sufficiency is achieved for solar overgeneration of around 36–40%, corresponding to a solar plant and electrolyser capacity of 150 MW and 45 MW. These general guidelines are meant to provide support for the design of low-carbon glass furnaces while minimising burdens on the broader energy system.