Thermodynamic, exergoeconomic, and economic analyses with multi-objective optimization of a novel liquid air energy storage coupled with an off-shore wind farm

The liquid air energy storage is a cutting-edge technology that covers the geographical drawbacks of other utility-scale energy storage alternatives. The coupling the liquid air storage system with renewable energies and heat recovery units can compensate the grid unstability and lack of their round trip efficiency, respectively. In the present paper, an off-shore wind farm including different wind turbines is assessed from technical, availability, and economic viewpoints to be combined with a liquid air energy storage unit, expolits a Kalina cycle for waste heat recovery. First, a comprehensive energy, exergy, and economic analyses are conducted for the integrated system; then, a coupling of artificial neural network and multi-objective genetic algorithm optimization method are carried out to find the optimum design condition. The findings show that around 93 MWh of the generated power in the wind site during off-peak period can be utilized to charge the system. Then, in addition to power generation in the wind farm, the reference system generates 76.4 MWh of extra power and 585 tons of domestic hot water during peak hours for peak shaving. Based on the optimization results, the round trip efficiency and total cost rate are 44.7% and 476 $/hr, repectively. The result of economic analysis demonstrated that the Enercon E-126 EP4 is the most cost-effective wind turbine for the proposed system, resulting in a period of 5.5 years. It has been also resulted that the existence of the LAES-KC system can half the paybacks.

Automated summary

Liquid air energy storage is an advanced technology that overcomes the geographical limitations of other utility-scale energy storage options. By combining the liquid air storage system with renewable energies and heat recovery units, it can address grid instability and low round trip efficiency. The study shows that the system can utilize around 93 MWh of power generated during off-peak periods and generate 76.4 MWh of additional power and 585 tons of hot water during peak hours. The optimized round trip efficiency is 44.7% and the total cost rate is $476/hr.