Integrating a battery value stacking approach into an energy system modelling framework to decarbonise a glassworks

Achieving climate neutrality requires decarbonisation across all sectors. While emissions from the German electric power sector show a promising trajectory, other sectors are progressing more slowly. This includes the industrial sector, where energy-intensive applications are particularly challenging due to the need for high-temperature process heat. The primary approach to decarbonising these applications is to maximise electrification where possible and to substitute the remaining demand for fossil energy carriers with renewable hydrogen or its derivatives. This usually comes with increased renewable power installations, including photovoltaic and wind power, which require redesign and operational adjustments to existing industrial energy systems. This may include battery storage systems to increase flexibility and align with the variable nature of renewable power generation. A challenging industrial application for decarbonisation is glassworks for automotive products. The main challenge is to increase the furnace's electrification and replace the primary energy carrier, natural gas, with hydrogen. One option for supplying renewable hydrogen is via pipeline as part of the planned hydrogen core network in Germany. The basic concept for this core network was already approved by the German Federal Network Agency in 2024, with phased commissioning until 2032. An alternative solution that can be realised in the short term is on-site production of green hydrogen via electrolysis. Supplying the electrolysis system with green electricity requires power purchase agreements that comply with the high legal requirements of the EU Renewable Energy Directive. Finding the most cost-efficient solution for industrial sites requires a sophisticated energy system modelling framework that can benchmark different solutions. There is a variety of frameworks featuring multiple approaches. The majority of frameworks are designed to model national or smaller regional grid-scale energy systems. Only a few frameworks focus on industrial scale. Therefore, a framework is developed specifically for local industrial flexumer applications. This includes integrating a value stacking approach for battery storage systems to demonstrate cost-reduction potential by leveraging additional flexibility. The developed framework is applied to a glassworks use case in Germany. The results show that, despite a decreasing trend towards 2037, decarbonisation choices lead to higher annual costs than rebuilding a natural gas-based furnace, by at least 18.3%. The most cost-competitive decarbonisation is achieved through high furnace electrification, which reduces hydrogen demand. By utilising low-cost renewable generation through power purchase agreements and battery storage, operating an on-site electrolysis system can be a competitive choice compared to connecting to a future hydrogen pipeline. Furthermore, in 2024, substantial additional cost reductions of up to 30.1% can be achieved when exploiting the flexibility of the electrolysis system and stacking multiple use cases for the battery storage system. Although the evaluation focuses on one specific glassworks use case, the results act as a blueprint for decarbonisation concepts for other industrial sites.