Periodic Reporting for period 1 - MATERIALIZE (Material Realizable Energy Transformation – Navigating the Material Bottlenecks of a Carbon-Neutral Energy System)
Berichtszeitraum: 2023-05-01 bis 2025-10-31
The transition to a low-carbon energy system requires the rapid deployment of renewable technologies such as solar panels, wind turbines, electrolysis for hydrogen production, and battery storage. However, many of these technologies depend on materials that are scarce, difficult to recycle, or highly concentrated in only a few regions of the world. Without careful planning, carbon reduction targets could be endangered, as resource bottlenecks might emerge, potentially limiting technology deployment.
The MATERIALIZE project investigates how material constraints may affect the pace and feasibility of global energy system transitions. It focuses first on so-called critical raw materials such as iridium, lithium, cobalt, and rare earth elements that play a key role in hydrogen production, battery storage, and other renewable technologies. The project aims to understand and quantify how much of these materials will be needed under future climate and energy scenarios, whether sufficient supply can be ensured, and how recycling, second-life applications, or technological innovation can mitigate potential material bottlenecks.
To address these questions, MATERIALIZE combines expertise from various research fields such as energy system modeling and industrial ecology. Its central objective is to develop tools and methods that allow material constraints to be integrated into quantitative models and ultimately assess material realizable energy transformation pathways. This enables a new generation of scenario studies where the availability of critical materials is treated as a binding factor in designing future energy systems.
The MATERIALIZE project investigates how material constraints may affect the pace and feasibility of global energy system transitions. It focuses first on so-called critical raw materials such as iridium, lithium, cobalt, and rare earth elements that play a key role in hydrogen production, battery storage, and other renewable technologies. The project aims to understand and quantify how much of these materials will be needed under future climate and energy scenarios, whether sufficient supply can be ensured, and how recycling, second-life applications, or technological innovation can mitigate potential material bottlenecks.
To address these questions, MATERIALIZE combines expertise from various research fields such as energy system modeling and industrial ecology. Its central objective is to develop tools and methods that allow material constraints to be integrated into quantitative models and ultimately assess material realizable energy transformation pathways. This enables a new generation of scenario studies where the availability of critical materials is treated as a binding factor in designing future energy systems.
During the first part of the project, MATERIALIZE has made substantial progress in developing new methods to quantify and model the demand for critical materials under future energy system transitions. These methods were applied to key technologies such as electrolysis, batteries, and photovoltaic supply chains.
The starting point of MATERIALIZE marked the development of ETHOS.ReFlow a lightweight resource flow model designed to support in-depth case studies of energy technologies. Initial applications included proton exchange membrane (PEM) electrolysis, battery storage, and water demand of electrolysis. For PEM electrolysis, ETHOS.ReFlow was used to evaluate global iridium requirements under different climate pathways, incorporating dynamic catalyst loadings, recycling efficiencies, and competing sector demands. In parallel, the tool was applied to battery technologies, including lithium-ion, sodium-ion, and solid-state variants, capturing circular economy dynamics such as second-life deployment and recycling. A physically grounded water model was also developed to simulate water demand of electrolysis, accounting for stoichiometric and thermal losses under site-specific meteorological conditions. These efforts provided high-resolution material and water demand datasets now used in broader system modelling and highlighted emerging bottlenecks in resource-constrained transition pathways.
In addition, initial research has begun on out-phased materials such as gypsum, a by-product of coal-based flue gas desulfurization, which may become scarce as fossil fuel use declines. A material flow analysis is under development to trace alternative gypsum sources and assess regional supply risks.
To further improve realism in energy modelling, a robust optimization method was introduced. This method stress-tests energy systems across multiple weather years to identify critical shortfalls (e.g. during cold dark lulls) and integrates representative stress periods back into the model through time-series clustering. This allows for the design of energy systems that are resilient not only under average but also extreme conditions.
Finally, MATERIALIZE has made significant progress toward embedding material flow constraints directly into the open-source optimization framework ETHOS.FINE. A modular extension named ETHOS.FINE.Resources enables the co-optimization of energy and material flows by linking material consumption to infrastructure commissioning and recycling to decommissioning. While the core architecture has been implemented and validated in test systems, further refinement and large-scale integration are ongoing. This development represents a major methodological advance, enabling resource-aware planning under real-world constraints.
The starting point of MATERIALIZE marked the development of ETHOS.ReFlow a lightweight resource flow model designed to support in-depth case studies of energy technologies. Initial applications included proton exchange membrane (PEM) electrolysis, battery storage, and water demand of electrolysis. For PEM electrolysis, ETHOS.ReFlow was used to evaluate global iridium requirements under different climate pathways, incorporating dynamic catalyst loadings, recycling efficiencies, and competing sector demands. In parallel, the tool was applied to battery technologies, including lithium-ion, sodium-ion, and solid-state variants, capturing circular economy dynamics such as second-life deployment and recycling. A physically grounded water model was also developed to simulate water demand of electrolysis, accounting for stoichiometric and thermal losses under site-specific meteorological conditions. These efforts provided high-resolution material and water demand datasets now used in broader system modelling and highlighted emerging bottlenecks in resource-constrained transition pathways.
In addition, initial research has begun on out-phased materials such as gypsum, a by-product of coal-based flue gas desulfurization, which may become scarce as fossil fuel use declines. A material flow analysis is under development to trace alternative gypsum sources and assess regional supply risks.
To further improve realism in energy modelling, a robust optimization method was introduced. This method stress-tests energy systems across multiple weather years to identify critical shortfalls (e.g. during cold dark lulls) and integrates representative stress periods back into the model through time-series clustering. This allows for the design of energy systems that are resilient not only under average but also extreme conditions.
Finally, MATERIALIZE has made significant progress toward embedding material flow constraints directly into the open-source optimization framework ETHOS.FINE. A modular extension named ETHOS.FINE.Resources enables the co-optimization of energy and material flows by linking material consumption to infrastructure commissioning and recycling to decommissioning. While the core architecture has been implemented and validated in test systems, further refinement and large-scale integration are ongoing. This development represents a major methodological advance, enabling resource-aware planning under real-world constraints.
MATERIALIZE has opened new frontiers in how we understand and plan for the energy transition by going beyond traditional energy modeling approaches. Rather than viewing material supply as a background assumption, the project puts it at the center of strategic decision-making. This shift enables entirely new classes of insights and scenario analyses that were previously out of reach.
Most existing energy models simulate how electricity, hydrogen, or fuels flow through future energy systems, but they assume that all required materials will be available. MATERIALIZE changes this logic. By embedding critical raw material constraints directly into energy system optimization tools, the project allows for co-optimization of both energy and material flows. This means that scenarios now take into account whether enough iridium, lithium, or other essential materials can realistically be supplied and what happens when they cannot.
These integrated perspectives are achieved through the extension of the energy system model framework ETHOS.FINE where resource constraints and recycling circles are endogenously integrated. The novel methodology allows policymakers and planners to explore alternative technologies, recycling strategies, and trade-offs between different sectors in a way that reflects actual resource limitations.
Many current resource assessments use fixed input assumptions and fail to account for technological advances or changing market dynamics, limiting their relevance for long-term planning. MATERIALIZE advances the field by developing flexible modeling tools that account for technological learning, evolving recycling systems, and competition between industries for the same materials. These approaches enable fast and easy to understand preassessments of potential material bottlenecks and how they might be mitigated using the ETHOS.ReFlow.
Planning for the future is not just about averages, it is about understanding how systems behave under stress. MATERIALIZE developed a robust optimization method that stress-tests energy systems against extreme conditions like multi-year periods of low renewable energy availability. By integrating these stress scenarios into the system design phase, the project enables the creation of infrastructure plans that are resilient to both climate variability and material shocks.
Together with high-resolution water models for hydrogen production, early-stage probabilistic frameworks for material criticality, and first-of-its-kind modelling of phased-out byproduct materials (e.g. FGD gypsum), these advances enable the design of energy systems that are not only greenhouse gas neutral, but also resilient, adaptive, and grounded in the physical realities of the 21st century.
Most existing energy models simulate how electricity, hydrogen, or fuels flow through future energy systems, but they assume that all required materials will be available. MATERIALIZE changes this logic. By embedding critical raw material constraints directly into energy system optimization tools, the project allows for co-optimization of both energy and material flows. This means that scenarios now take into account whether enough iridium, lithium, or other essential materials can realistically be supplied and what happens when they cannot.
These integrated perspectives are achieved through the extension of the energy system model framework ETHOS.FINE where resource constraints and recycling circles are endogenously integrated. The novel methodology allows policymakers and planners to explore alternative technologies, recycling strategies, and trade-offs between different sectors in a way that reflects actual resource limitations.
Many current resource assessments use fixed input assumptions and fail to account for technological advances or changing market dynamics, limiting their relevance for long-term planning. MATERIALIZE advances the field by developing flexible modeling tools that account for technological learning, evolving recycling systems, and competition between industries for the same materials. These approaches enable fast and easy to understand preassessments of potential material bottlenecks and how they might be mitigated using the ETHOS.ReFlow.
Planning for the future is not just about averages, it is about understanding how systems behave under stress. MATERIALIZE developed a robust optimization method that stress-tests energy systems against extreme conditions like multi-year periods of low renewable energy availability. By integrating these stress scenarios into the system design phase, the project enables the creation of infrastructure plans that are resilient to both climate variability and material shocks.
Together with high-resolution water models for hydrogen production, early-stage probabilistic frameworks for material criticality, and first-of-its-kind modelling of phased-out byproduct materials (e.g. FGD gypsum), these advances enable the design of energy systems that are not only greenhouse gas neutral, but also resilient, adaptive, and grounded in the physical realities of the 21st century.