New concept for energy storage: Microwave-induced carbon gasification with CO2

•A new system for energy storage based in microwave-induced gasification is proposed.•From the carbonaceous materials tested, charcoal yielded the best results.•The systems achieved energy efficiencies of about 45% without any optimization.•The system is competitive in terms of efficiency with some conventional systems.

Energy storage is a topic of great importance for the development of renewable energy, since it appears to be the only solution to the problem of intermittency of production, inherent to such technologies. In this paper, a new technology for energy storage, based on microwave-induced CO2 gasification of carbon materials is proposed. The tests carried out in this study on different carbon materials showed that charcoal consumes the least amount of energy. Two microwave heating mechanisms, a single-mode oven and a multimode device, were evaluated with the latter proving itself to be the more efficient in terms of energy consumption and recovery. The initial results obtained showed that this technology is able to achieve energy efficiencies of 45% at laboratory scale with every indication that these results can be improved upon to make this approach highly competitive against other energy storage technologies.