Criticality assessment of indium for thin-film photovoltaics in the context of sustainability goals for the German housing sector

In countries with large import dependencies, several studies on strategically important metals have classified raw materials as being critical by combining supply and vulnerability risks. In case of availability, the most critical raw materials are metallic ores and industrial minerals. Within the scope of developing resource efficient buildings, innovative building technologies, such as renewable energy systems, are becoming increasingly integral parts of buildings. Since critical raw materials are essential components in building technologies, they will also play an important role in the housing sector. In this context, it is crucial to consider how sustainability goals in the housing sector are affected by raw material criticality. This paper addresses supply and vulnerability risks of indium, which is contained in thin-film photovoltaics, in order to identify their impacts on future developments in the housing sector. Raw material availability is significantly influenced by the demand and supply of raw materials. To implement risk factors for a criticality assessment in sector-specific material flows, their impacts are analysed and modelled using a dynamic, macro-economic approach. Assuming different energy scenarios in the German housing sector up to 2050, the model reveals the raw material criticality by pointing out supply risks in order to derive recommendations.