Evaluating operating strategies of large-scale industrial battery storage – A case study of a glassworks site

The industry sector largely contributes to greenhouse gas emissions. Yet only a few measures were taken in the last decade to significantly reduce those emissions. However, different industry players have recently implemented steps to decarbonize their operations by switching from fossil fuels to renewable energy sources. This goes along with the increased need for electrification of all energy sectors through sector coupling. Battery storage offers the opportunity to balance increased and more volatile electricity demand to supply. In this work a case study of a glass melting and manufacturing site is presented.

For modeling of the industrial site, the mixed-integer linear programming (MILP) FOCUS-Framework for energy system optimization developed at RWTH Aachen is used. The modeling separates the glass melting and glass manufacturing complexes. For the consumption of both complexes, high-resolution 15-minute measurement data for natural gas and electricity is provided. The model is extended by adding a detailed representation of the existing 2.2 MW_el
combined heat and power (CHP) plant. It operates in heat-led mode to mainly supply heat for the production process. A battery is modeled with a multi-use approach to test operating strategies like peak shaving and the increase of self-consumption from renewable generation.

Without any renewable generation, the optimal battery size for peak shaving of the site load is 1.06 MWh (Fig.1). By gradually adding available PV and WT capacity the optimal size increases to 5.8 MWh. This highlights that apart from peak shaving the battery is intensively used for increasing self-consumption. This is supported by the annual usage hours which are higher with increased renewable generation (Fig. 2). The cycling of the batteries ranges from 2 to 257 equivalent full cycles (EFC) which fits the expected cycling with the modeled operation strategies. Overall, with battery and renewables cost savings of up to 7.1% can be achieved. Future work will focus on adding additional services like arbitrage and frequency control to the battery operation to increase its financial benefit. In addition, full decarbonization of the glass melting process with hydrogen and increased electric boosting will be analyzed.