The efficiency comparison between liquid air energy storage (LAES) and compressed air energy storage (CAES) shows that LAES generally offers competitive or potentially higher round-trip efficiency with further benefits from integrated thermal management.
Liquid Air Energy Storage (LAES) Efficiency:
- Standalone LAES systems typically achieve around 57% round-trip efficiency.
- Advanced LAES concepts that integrate external thermal inputs, such as oxy-fuel combustion and waste heat recovery, can improve output power significantly while boosting round-trip efficiency by about 56.7% compared to conventional LAES designs, despite a slight drop in exergy efficiency.
- Incorporating above-ambient heat sources during the reconversion phase enhances LAES efficiency by reducing energy losses related to the liquid air’s low boiling point.
Compressed Air Energy Storage (CAES) Efficiency:
- Although exact efficiency figures for CAES are not provided, CAES systems traditionally have efficiencies ranging from 40% to 55% in many cases due to energy losses in compression and heat dissipation, especially if heat recovery is not optimized.
- CAES efficiency can be improved with advanced adiabatic and isothermal designs, but these often add complexity and cost.
Summary and Comparison:
| Feature | Liquid Air Energy Storage (LAES) | Compressed Air Energy Storage (CAES) |
|---|---|---|
| Typical Round-trip Efficiency | About 57% (standalone); can be higher with thermal integration (~56.7% improvement in advanced systems) | Generally 40-55%, depending on heat management |
| Thermal Integration | Uses waste heat and external fuel combustion to boost efficiency and output power | Heat recovery possible but complex and costly |
| Flexibility | Can provide additional heating and cooling services during discharge | Typically focused on electricity only |
| Economic and Practical Aspects | Competitive low cost of storage; potential for multi-use applications | Well-established but limited by thermodynamic losses |
Overall, LAES tends to offer higher and more flexible efficiency due to the integration of thermal management processes, potentially outperforming CAES in round-trip efficiency and economic viability for grid-scale storage. The ability to harness waste heat and external thermal energy sources makes LAES a promising energy storage technology compared to conventional CAES.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-efficiency-of-liquid-air-energy-storage-compare-to-compressed-air-energy-storage-2/
