Green Critical Minerals’ VHD blocks could revolutionise solar thermal energy storage

Solar thermal energy storage potential of Green Critical Minerals’ VHD block tech is being investigated
Initial modelling found that a 1.2m by 1.2m by 0.25m VHD block could store power for typical household for up to two days
Advanced computer simulation being developed to optimise solar-thermal system performance

Special Report: Green Critical Minerals’ recently acquired VHD block tech could play a role in the net zero transition after investigations found the high-density graphite blocks it produces could be used to store solar-thermal energy.

Initial modelling by Professor Charles Sorrell, who invented the technology, had demonstrated that a 1.2m by 1.2m by 0.25m VHD block can store enough energy to power a typical household for up to two days.

Green Critical Minerals (ASX:GCM) is now developing an advanced computer simulation to optimise solar-thermal system performance under various conditions, ensuring efficient energy capture, storage and release for industrial-scale clean power generation from VHD blocks.

The company had acquired the VHD block technology in late October 2024, drawn by its ability to convert graphite into very high-density graphite blocks that have among the highest thermal conductivity ever recorded for any bulk material – up to 617 W/m·K along the grain – and the lowest electrical resistivity (of 1.2 µΩ·m) ever measured for any bulk graphite product.

Notable applications include materials for the defence and nuclear industries, thermal energy storage systems, high-performance electronics, battery electrodes, heat sinks and aerospace.

Adding interest, the technology is set apart from traditional processes by its highly efficient breakthrough production process that requires less time, lower graphitisation temperatures and does not require any specialised infrastructure or complex manufacturing techniques.

Construction is currently underway on a pilot plant to produce VHD blocks suitable for demonstration-scale solar-thermal energy systems and further validation of their performance.

In parallel, the company is actively pursuing strategic partnerships with energy companies, end user and government agencies to accelerate the adoption of VHD technology and support development of clean, constant power solutions.

Illustration of possible clean constant energy using CSP, VHD tech and steam turbine system. Pic: Green Critical Minerals

Storing solar thermal energy

The exceptional thermal conductivity and unmatched thermal stability at temperatures exceeding 3000 degrees Celsius in inert conditions of VHD graphite blocks make them compatible with concentrated solar power (CSP) and induction heating systems.

It enables versatile renewable energy solutions by efficiently capturing and storing energy for consistent power generation and allows the company to tap into the solar-thermal energy storage market, which is projected to exceed US$35bn by 2031 according to Allied Market Research.

GCM’s computer stimulation model will account for various meteorological conditions across different locations, providing key insights for the design of the solar-thermal system.

This will analyse the entire process, from renewable energy capture to storage and discharge of thermal energy, and finally to the generation of constant, industrial-scale electricity.

It will also model the behaviour of the solar-thermal system, from the initial capture of renewable energy to storage and discharge of thermal energy, and finally to generation of electricity – constant power at an industrial scale.

De-risking this process is the years of back-testing that have already been conducted on the unique properties of VHD blocks along with their historical production, which guide the design and application of the technology.

Completion of this computer model will inform the production of graphite blocks from the VHD technology for lab-scale simulation of a solar-thermal system, prior to progressing to the construction of a demonstration-scale solar-thermal renewable energy system.

VHD tech is also scalable from small-scale microgrids all the way up to a large, utility-scale solar-thermal power plant.

Solar-thermal energy

In a CSP system, solar thermal energy captured by mirrors or lenses is transferred to VHD blocks that store the heat, which can be discharged later as thermal energy when the sun isn’t shining.

Energy captured by solar photovoltaic (solar panels) or wind turbines can also be stored in VHD blocks via induction heating.

Thermal energy discharged by VHD blocks can be transferred to a working fluid that drives a steam turbine or other power generation system to convert the thermal energy into electricity, ensuring a continuous supply of power regardless of sunlight or wind availability.

This article was developed in collaboration with Green Critical Minerals, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.