Tailored Oxide-Molten Salt (OMS) Composites for High-Operating-Temperature Thermal Energy Storage

The difficulty in both utilizing industrial waste heat, as well as time shifting heat production vs. utilization is a major barrier to decarbonizing US manufacturing. Several industrial sectors such as steel and glass manufacturers produce large amounts of high temperature “waste” heat. However, absent energy storage, this power must be utilized near simultaneously with waste heat generation, making it difficult for manufacturers to shift utilization in response to the availability of renewable energy sources. Proposed Solution: We propose to develop a unique family of dual-phase, perovskite oxide-molten salt (OMS) composites with tunable phase transition temperatures for thermal energy storage. The novel OMS materials offer many unique advantages including: (a) phase-transition like behavior for high energy storage capacity; (b) tunable temperature windows suitable for both subcritical and (ultra) supercritical steam plants with high roundtrip efficiency; (c) particulate exoskeleton for easy handling and minimal corrosion; (d) faster heat transfer compared to conventional, solid-based energy storage materials; (e) and high efficiency in a simple, single-tank configuration. What is to be done in Phase I: Phase I will focus upon: (1) Screening and optimization of OMS particles to demonstrate > 600 kJ/kg energy storage capacity for 150 °C temperature windows covering 450 to 1000+ °C; (2) Demonstrate the robustness and ease of handling for OMS materials for over 100 hours; (3) Techno-economic evaluation of these particles with respect to various waste/industrial heat sources and power generation cycles to determine cost and “roundtrip” exergy efficiency; and (4) Identifying promising system design and configurations for further investigations in Phase II. This will be accomplished though synthesis, testing and screening of OMS composites; modeling integration of the OMS system with manufacturing plants; and evaluating the economics of the system in light of these experimental and modeling results. Commercial Applications and Other Benefits: An energy storage system that can take up and store waste heat generated by manufacturing processes during periods of high renewable energy supply and release it during periods of decreased renewable power supply can add significant value. If successful, the propose system could supply cheap energy storage to steel, glass, and chemical plants, allowing them to handle variations in renewable energy supply, resulting in faster adaptation of low CO2 energy.