DEFT: Decentralized energy storage for increasing flexibility of thermal processes
Industrial Collective Research (IGF), 1 September 2026 – 31 August 2028
Project description
The process heat demand of the German metal, glass, and ceramics industries accounts for about one-third of industrial energy consumption and is met by fossil fuels to more than 90 percent. As part of the energy transition, processes are increasingly being (partially) electrified, which is driving up electricity demand. At the same time, the expansion of renewable energy sources increases the risk to energy supply due to volatile grid utilization and electricity prices. Therefore, processes must become more flexible to adapt to fluctuating conditions. One strategy is the installation of decentralized energy storage systems and their integration into the processes. This creates new challenges for plant operators, grid operators, and suppliers, but also opens up market potential.
Project goals
The project investigates potential applications of energy storage systems in thermal processing technology. To this end, it examines which storage technologies (e.g., sodium-sulfur and lithium-ion batteries, as well as sensitive ceramic heat storage systems) best complement thermal processes in various industries. Virtual company sites are modeled as mathematical representations of local electricity and heat systems comprising sources, storage systems, and processes, and are analyzed in terms of process control and economic efficiency. The goal is to determine when storage systems are practical and cost-effective, to derive design guidelines and operating strategies from these findings, and to develop control concepts based on supply conditions. In addition, the grid’s response to the widespread use of decentralized storage systems is being investigated.
The project consists of three subprojects:
EcoDEFT
The EcoDEFT subproject aims to conduct an economic assessment of the use of decentralized energy storage systems in conjunction with thermal processes and to derive decision-making guidance for investment and operation. Both technical process requirements and current and future developments in the energy market are taken into account.
The project will first characterize available storage technologies using technical and economic metrics and evaluate their suitability for industrial thermal processes. At the same time, an electricity market model for the integrated scheduling of industrial consumers will be further developed and expanded to include various future energy market scenarios. Based on the process requirements and storage metrics, suitable process-storage combinations will be selected and sized. Subsequently, different operating scenarios will be evaluated economically and compared with the state of the art. Sensitivity analyses will be used to identify key factors influencing the economic viability of storage operations.
From these results, a transferable decision-making tool is derived for the selection, sizing, and cost-effective operation of energy storage systems. The outcome is a practice-oriented guide that summarizes recommendations for future investment and operational decisions and is integrated with the results of the linked subprojects.
ModelDEFT
The ModelDEFT subproject aims to further develop an energy system simulation environment for thermal process chains and, building on this, to implement and validate process and storage models and make them usable for technical recommendations.
The project will first expand the existing FOCUS Framework—an open-access software platform for simulating energy systems—into a modular simulation environment. Subsequently, models will be developed to represent the systems relevant to thermal process technology. This includes the implementation of process models for exemplary thermal process steps, electrochemical storage models, and thermal storage models. Models for both types of storage will also be supplemented by design tools. The individual models will be integrated into the simulation environment and combined into complete local energy system models. The resulting model chains will be verified through short-term simulations. This will be followed by computational time optimizations and long-term simulations of various process and storage configurations.
The simulation results are technically evaluated and translated into recommendations for action. Based on this, recommendations for storage sizing and storage operation are defined. The result is a guide that consolidates the findings from this subproject as well as the linked subprojects.
ProcessDEFT
The ProcessDEFT subproject aims to flexibly integrate thermal processes and decentralized energy storage systems through model-based process integration, automation, and optimization, thereby enabling technically and economically optimized operation. To this end, standardized data structures, decision-making and optimization models, and a digital assistance system are being developed.
The project will first define the functional, data-related, and automation-relevant requirements for the integrated process-storage operation. Building on this, structured data and metadata models, as well as AAS submodels, will be developed to enable standardized and interoperable use of process, storage, and energy system data. An end-to-end data pipeline is used for the automated collection, processing, and provision of the required operational data. In addition, decision-making logic and optimization algorithms are being developed that take into account process states, storage limits, and technical and economic metrics. The models are linked to simulations from ModelDEFT and energy-related input data from EcoDEFT.
The methods developed are integrated into a digital assistance system that visualizes process and storage states, analyzes key performance indicators, and provides recommendations for operational actions. The result is a practical guide to data integration, automation, and the optimized coupling of thermal processes and energy storage systems.
Project participants
- RWTH Aachen University
IOB – Department for Industrial Furnaces and Heat Engineering - RWTH Aachen University
IAEW – Institute of High Voltage Equipment and Grids, Digitalization and Energy Economics - RWTH Aachen University
ISEA – Institute for Power Electronics and Electrical Drives - RWTH Aachen University
IAT – Chair of Information and Automation Systems for Process and Material Technology
Contact
Manuel Sanders, M.Sc.
+49 241 80–26066
Jan Erik Menzler, M.Sc.
+49 241 80–25944
Luis Schrade, M.Sc.
+49 241 80–25925
Kalyan Yarramsetty, M.Sc.
+49 241 80–28921
Felix Kaiser, M.Sc.
+49 241 80–25943
Funding
EcoDEFT
The subproject EcoDEFT (project no. 01IF008AE) as a part of the research project DEFT was submitted with the support of the Forschungsgemeinschaft für elektrische Anlagen und Stromwirtschaft e.V. (FGH). It received funding from the German Federal Ministry for Economic Affairs and Energy (BMWE) through the project management agency German Aerospace Center (DLR) as part of the programme for the promotion of industrial joint research and development (IGF), based on a resolution of the German Bundestag.
ModelDEFT
The subproject ModelDEFT (project no. 01IF008BE) as a part of the research project DEFT was submitted with the support of the Research Association for Industrial Furnace Engineering (FOGI). It received funding from the German Federal Ministry for Economic Affairs and Energy (BMWE) through the project management agency German Aerospace Center (DLR) as part of the programme for the promotion of industrial joint research and development (IGF), based on a resolution of the German Bundestag.
ProcessDEFT
The subproject ProcessDEFT (project no. 01IF008CE) as a part of the research project DEFT was submitted with the support of the Forschungsvereinigung Elektrotechnik beim ZVEI e.V. It received funding from the German Federal Ministry for Economic Affairs and Energy (BMWE) through the project management agency German Aerospace Center (DLR) as part of the programme for the promotion of industrial joint research and development (IGF), based on a resolution of the German Bundestag.