High efficiency cryo-adsorbed hydrogen energy storage

Abstract

The landscape of energy storage technology is rapidly evolving, characterized by a variety of solutions that aim to achieve higher efficiency, greater scalability, and better integration with renewable energy sources. These advancements are crucial for meeting increasing demands and speeding up the transition to a sustainable energy future. The presented research proposes an energy storage method, which is characterized by a low power consumption (high efficiency) and the suitability for large-scale facilities, with energy storage capacities reaching tens of GWh and power outputs in the range of a few GW. The technology can be implemented in any location without a need for specific geographical conditions, and it has the potential for small dimensions and low-cost, in comparison with alternative existing technologies, mainly hydro pumped and compressed air energy storage. The proposed approach consists of storing energy in adsorbed hydrogen at cryogenic temperatures between 80 and 180 K, and pressures of a few tens of bar. The concept of cryo-adsorbed hydrogen energy storage is presented and discussed, where a selected cycle is detailed as an example for implementing the suggested energy storage concept. A thermodynamic analysis of the cycle is executed, providing its energy consumption, which determines the system efficiency, as a function of the hydrogen storing temperature, system configuration, and energy storage duration. The results show energy consumption of about 2 MJ per 1 kg of stored hydrogen, relative to at least 10 MJ per 1 kg of stored hydrogen at existing compressed hydrogen energy storage systems.