A social sustainability assessment of a newly developed solar thermal energy system for industrial integration

• The social sustainability of an industrial solar thermal system is conducted. • The system consists of a SunDial, PCM storage tank, and control unit. • Supply-chain social risks are quantified using a risk-hour SHDB framework. • PCM storage components showed the highest social risk. • Manufacturing location strongly influences health, safety and labour risks. The deployment of solar thermal energy (STE) systems plays a critical role in decarbonising industrial heat demand; however, their sustainability performance includes not only technical efficiency and environmental impacts but also social considerations across the supply chain. This study presents a comprehensive social sustainability assessment of a newly developed STE system focusing on the manufacturing stages of its main components: SunDial concentrator, a phase change material (PCM) thermal storage tank, and a control unit. Social risks were quantified using a database driven risk hour (RH) approach, across different impact categories. including health and safety (H&S), fair payment, excessive working time, gender equality and policy compliance. The data were collected using Social Hotspot Database (SHDB) software, which simulated social risk levels based on material quantities and countries of origin of system components. The results revealed that social risks are strongly dependent on country of origin and economic sector, rather than material quantity alone. Manufacturing of PCM tank subcomponents in the Polish non-ferrous metals sector showed increased H&S risks, largely driven by high policy non-compliance and exposure to metal dust, while chemical production in the Netherlands showed substantially lower social risks due to stricter regulatory implementation. Similarly, the SunDial component manufactured in Spain demonstrated moderate H&S and gender inequality risks within the steel sector, while comparable components produced in Germany showed consistently low social risk levels. The findings highlight the importance of geographically and sector specific social assessments when sourcing components for renewable energy systems. Incorporating social sustainability metrics at early stages of design can guide responsible supply chain decisions, improving the overall sustainability performance and social acceptability of industrial STE technologies.