Comprehensive assessment and multi-objective optimization of a green concept based on a combination of hydrogen and compressed air energy storage (CAES) systems

In this paper, a novel efficient and environmentally-friendly hybrid energy production/storage system comprising a compressed air energy storage, a heliostat-driven Brayton cycle, and a hydrogen production unit is proposed and thoroughly investigated. The aim is to minimize the pollutant emission of compressed air energy storage technology while adequately addressing intermittency and electricity curtailment of power grids with high penetration of renewable sources. The proposed system uses the surplus power and wasted heat of the solar powered Brayton cycle to store pressurized air and hydrogen during off-peak periods, and releases them for extra power generation during peak demand periods. For the performance analysis of this hybrid solution, the reference system is precisely analyzed from thermodynamic and economic points of view. Then, training the results of the developed model employing an artificial neural network, four multi-objective optimization programs based on MOPSO, NSGA-II, PESA-II, and SPEA2 algorithms are performed to find an optimal trade-off between thermodynamic performance and economic attractiveness of the system. It is concluded that the system has an exergy round trip efficiency of 60.4% and a total cost rate of 117.5 $/GJ at the optimum solution. Applying the proposed method for the case study of Los Angeles with real historical data, 3313 ton/year Carbone-Dioxide emission is prevented, resulting in around 80,000 $/year environmental cost reduction. Also, the economic analysis indicates a payback period of shorter than 4.6 years for the system.

Automated summary

This paper proposes a novel hybrid energy production/storage system that utilizes a solar-driven Brayton cycle to store compressed air and hydrogen during off-peak periods for extra power generation during peak demand. Through multi-objective optimization algorithms, the system achieves a balance between thermodynamic performance and economic attractiveness, resulting in environmental benefits and cost reduction.