Life Cycle Assessment of Air-Rock Packed Bed Storage System and Its Comparison with Other Available Storage Technologies for Concentrating Solar Power Plants

Recently, packed bed of rocks using air as heat transfer fluid has been considered a promising alternative solution for thermal energy storage (TES) able to work in high temperature concentrating solar plants. In fact, the large amounts of mine by-product could be major source of cost-effective and eco-friendly filler materials. The present research work aims to quantify the environmental impact of air-basalt packed bed storage system. A comparative life cycle analyses were performed to give factual criteria to decision-makers for proper choices of TES materials. The embodied energy, GHG emissions and water consumption of the storage system during its whole life cycle have been presented. The following work is in accordance with the international standard series ISO 14040. By comparing with other TES technologies, "two tanks molten salts", "thermocline/molten salts with recycled ceramic", "thermocline/molten salts with Mullite", the "thermocline/air with basalt" showed a significant reduction in environmental impacts. These were reduced by 65% for primary energy demand, 60% for potential climate change and 80% for water consumption compared to the conventional two tanks molten salt storage system. The energy and global warming payback times of the proposed storage technology were very low (about 2 months) for a more than 25 years of expected lifetime.