Self-recuperative liquid air energy storage system: A new sustainable approach for uninterrupted power supply

Abstract

Liquid air energy storage (LAES) system is an emerging but promising candidate solution to the intermittency and weather/climate dependability issues of renewable energy. It is also envisioned as an energy vector for its multi-faceted potential applications, especially in the energy supply chain systems, and its ability to satisfy off-terrain demands. During low energy demand, the air is liquefied and later regasified to generate electricity when needed. However, the low round-trip efficiency of the conventional approaches (∼50%) is a challenge. The present study proposes a novel self-recuperative process whereby stored liquid air is used as a refrigerant instead of external mechanisms. Four slightly modifying configurations have been studied; the best case recuperates with the cold box and the compression heat during the discharging half cycle before power recovery. The case studies are simulated using Aspen HYSYS®. This excellent integration results in a round-trip efficiency of 75.8% and a specific energy consumption of 0.071 kWh/kgLA. The proposed process consumes 39.8 MW power, 58% less than the base case, resulting in 0.10 $/ton of levelized cost (production). The scheme opens up multiple pathways for liquid air, from further integration opportunities to its service in a continuous power generation mode as a transport medium and energy source in remote/off-grid locations. However, a dynamic and control strategy study should be conducted.