Two novel clean energy sources for generation and storage

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Hydrogen-metal and graphene systems offer the prospect of new sources for clean energy generation and storage.

With the drive for large scale decarbonisation demand is growing for new efficient clean energy sources for many applications.

One such emerging energy source with promise is hydrogen-metal energy, which is gained when hydrogen reacts with some metals under slightly increased temperature and pressure. First experiments have shown that the total heat energy produced exceeds by many orders of magnitude the chemical energy but strongly depends on the applied active metallic materials and gas conditions in special reactors.

Furthermore, accelerator experiments performed at higher energies have shown that the reaction rates can be enhanced by many orders of magnitude if metallic samples with special nanostructures or crystal lattice defects are utilised.

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Little research has been conducted so far on hydrogen-metal energy and the CleanHME project, which was launched in August 2020 with EU Horizon 2020 support, is aiming to change this. Objectives are to elaborate a comprehensive theory of hydrogen-metal energy phenomena in order to optimise the choice of materials for the process and to improve the reactor design with construction of a new compact reactor to test hydrogen-metal energy technology.

The proposed solutions have the potential to be a breakthrough for the power supply industry with potential applications including small mobile systems and stand-alone heat and electricity generators.

The project is due to run to August 2024.

Graphene-based storage

Hydrogen is emerging as a promising option for long term storage of energy. However, with the majority of hydrogen coming from breaking the carbon-hydrogen bonds in hydrocarbons, the extraction includes CO2 emissions.

The Horizon 2020 supported LESGO project, which launched in November 2020, aims to address this with storage in the carbon-hydrogen bond of reduced graphene oxide, i.e. graphene with a much reduced oxygen content. Among other aspects, the project will investigate the characteristics of chemically binding hydrogen onto the carbon atoms of a graphene oxide lattice.

Graphene oxide is formed by the oxidation of graphite, which is cheap and readily available, and thus reduced graphene oxide is potentially the best solution for securing large quantities of graphene for industrial applications. Advantages include safe storage, easy transportation, an energy density over 100 times larger than that of hydrogen gas and no carbon emissions in the electricity generation process.

The LESGO project, running until October 2023, aims to provide innovative solutions for high density storage, transportation and delivery of energy on demand from reduced graphene oxide.

A broad spectrum of application areas are anticipated and particularly in the transport sector. The project will develop an application to test reduced graphene oxide as the fuel in a support battery providing fast charging for electric vehicles.