To improve the round-trip efficiency of liquid air energy storage (LAES) systems, researchers and industry players have developed multiple strategies:
Hybridization with External Thermal Systems
Integrating waste heat or cold from external sources significantly boosts efficiency. For example:
- Waste heat utilization: Injecting high-grade waste heat during air expansion increases power output. This can elevate efficiency to ~70% in peaking plants and >100% when combined with LNG waste cold.
- Waste cold recovery: Leveraging cryogenic waste cold (e.g., from LNG regasification) reduces energy consumption during air liquefaction, improving standalone efficiency to ~60%.
Advanced System Design and Optimization
- Thermodynamic cycle improvements: Multi-stage compression/expansion and optimized pressure ratios enhance efficiency. For instance, a hybrid LAES system demonstrated 9–12% higher round-trip efficiency than conventional setups by better managing heat/cold storage.
- Cold storage with packed beds: These improve heat exchange during discharge, increasing efficiency by up to 50% in validated models.
- Exergy efficiency optimization: Algorithm-driven models and component-level refinements (e.g., pressurized phase separators) reduce energy losses.
Standalone Innovations
A novel standalone LAES design from Dongguk University avoids dependency on external facilities by integrating internal thermal management, addressing geographic flexibility while improving efficiency. This approach avoids CO₂ emissions linked to external fuel use, unlike hybrid systems that may rely on supplementary fuels.
Operational and Material Enhancements
- Higher-grade heat sources: Using above-ambient heat during discharge improves air expansion efficiency.
- Multi-stage processes: Two-stage compression paired with efficient heat exchangers minimizes specific energy consumption.
By combining these methods, LAES systems can achieve round-trip efficiencies exceeding 60%, with further gains possible through waste energy integration.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-can-the-round-trip-efficiency-of-laes-systems-be-improved/
