Advancements in technology have significantly improved the efficiency of liquid air energy storage (LAES) systems through several key innovations and process optimizations:
Key Technological Improvements Enhancing LAES Efficiency
- Thermal Energy Storage and Recycling: Modern LAES systems greatly improve cycle efficiency by capturing and recycling thermal energy released during air expansion (discharge) to reduce energy consumption during air liquefaction (charging). This “cold recycle” process minimizes the work needed to liquefy air and enhances overall round-trip efficiency. Pilot projects demonstrated effective storage and reuse of low-grade heat and cold energy, achieving round-trip efficiencies up to 60%, which surpasses earlier targets of >50%.
- Process Design Optimization: Modifications in the number and placement of cold expansion turbines and changes in the liquefaction cycle (moving beyond the standard twin turbine Claude cycle) allow for more efficient utilization of stored cold. This results in better thermal integration and less heat loss, contributing to higher system efficiency.
- Hybrid Systems with External Thermal Input: Integrating oxy-fuel combustion using natural gas as an external thermal energy source during discharge increases power output. In this approach, part of the liquid air is separated into oxygen and nitrogen, with oxygen used to combust natural gas cleanly, generating extra heat to boost the expansion process. This method has shown to nearly double the power output (by about 130%) compared to conventional systems, while also providing heating and cooling outputs. Although it slightly reduces exergy efficiency, it markedly improves round-trip efficiency by about 56.7%.
- Location and Integration Benefits: Efficiency improves further when LAES plants are located near energy sources, reducing thermal and electrical losses associated with transport and storage.
Efficiency Gains in Quantitative Terms
| Improvement Aspect | Efficiency Metric & Impact |
|---|---|
| Cold recycle and thermal storage | Up to 60% round-trip efficiency (pilot scale) |
| Hybrid oxy-fuel combustion system | 56.7% higher round-trip efficiency; 129.9% higher power output than conventional systems |
| Economic viability | Levelized cost of storage (LCOS) ~ $60/MWh, about 1/3 lithium-ion and 1/2 pumped hydro costs |
Summary
Technological advancements such as thermal energy recycling, optimized turbine cycles, integration of oxy-fuel combustion for additional thermal input, and strategic plant siting collectively lead to considerable gains in LAES system efficiency. These innovations push round-trip efficiencies well above 50%, sometimes reaching 60%, and significantly increase power output while reducing costs, making LAES a competitive and promising grid-scale energy storage solution for future decarbonized energy systems.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-efficiency-of-liquid-air-energy-storage-systems-improve-with-advancements-in-technology/
