Caldera debuts Megacell, a new era of heat storage solution using recycled aluminium & volcanic rock

UK-based startup Caldera has developed a modular heat storage technology named Megacell, utilising a composite of abundant natural materials, including recycled aluminium and volcanic rock. This new heat storage technology is described as an ideal solution for decarbonising industrial processes and storing on-site photovoltaic energy.

Image source- Caldera

Decarbonisation, or moving towards an emission-free world, is one of the most important aspects of the aluminium industry. Aluminium, though recyclable or sustainable, is one of the reasons behind the emission of greenhouse gases (GHGs) worldwide. As a result, the decarbonisation of aluminium subsectors has become mandatory to reduce direct and indirect emissions.

The system is designed to convert on-site solar power into on-demand heat, capable of replacing conventional gas boilers by storing heat at temperatures of up to 500°C and producing steam. The system's core, made from a proprietary composite of recycled aluminium and volcanic rocks, offers thermal storage capacity comparable to other rock, sand, or concrete technologies.

Features of Megacell

Megacell features a vacuum-insulated chamber capable of storing heat at temperatures up to 500°C and can produce hot water or steam at temperatures up to 210°C. The company also claims its insulation is highly space-efficient, allowing the unit to remain compact. The heat cell cores are enclosed within a vacuum flask and are heated using standard electric elements.

"The vacuum prevents conduction and convection of heat, while an additional material prevents radiative losses. A closed steam loop runs through each heat cell to maintain ultra-high purity and prevent eventual degradation from the build-up of solids. It is the cheapest and most efficient means of insulating the thermal core taking into account construction costs, insulation selection and weather proofing," said the company.

The company offers Megacell storage capacities of 1.3 MWh, 4 MWh, and 5.3 MWh, along with options for a steam generator, compact substation, and storage boiler. The smallest unit measures 6 m x 14 m x 7.3 m, while the largest is 6 m x 14 m x 9 m, with weights ranging from 27 tonnes to 82 tonnes. The modular design combines multiple units, enabling storage capacities of up to 100 MWh. Caldera has built the first 4 MWh demonstrators at its factory in Hampshire.