Comparative life cycle assessment (LCA): Conventional TES system versus alternative steel slag-based TES system for CSP plants

Abstract

There is a demand for alternative thermal energy storage (TES) materials to support the global deployment of concentrated solar power (CSP) plants. These materials should fulfil specific criteria concerning technical, economic, and ecological performance. This research work focuses on the comparative life cycle assessment (LCA) of a concentrating solar power (CSP) plant that utilizes Electric Arc Furnace (EAF) steel slag as a thermal energy storage material in a thermocline configuration, compared to a conventional CSP plant that uses molten salts. The study aims to evaluate the potential environmental impacts and identify opportunities for sustainability improvement in CSP plants technology. The results demonstrate a significant reduction in the material inventory demand and in the overall environmental impact for the scenarios where the thermocline configuration was chosen. The thermocline TES system showcases notable reductions in the following environmental impact indicators: a) “Damage to the resources availability” and b) “Global warming potential”. Thus, the study highlights the potential of using steel slag to improve the sustainability of CSP plants, while revalorising materials that other case could finish in a landfill. The research and analysis performed indicate that the use of steel slag as a thermal storage material is technically feasible and it has the potential to increase the environmental and economic sustainability, as this material is abundant, energy efficient and sustainable enough for industrial scale applications. In fact, the use of steel slag as TES material could contribute positively to the Sustainable Development Goals (SDGs) through: including cleaner energy solutions, promoting innovation in green power generation, responsible managing of resources, and mitigating the climate change