Technology: Inside a Heat Cell
The heat cell is the enabling innovation in every Caldera system, allowing intermittent renewable energy to be converted to on-demand heat. Multiple heat cells are installed to meet the site’s requirements, and this array can sit outside. The suite of patented and patent-pending technologies needed to make a heat cell took years to develop, yet the principles behind it are surprisingly simple.
Technology: Inside a Heat Cell
The heat cell is the enabling innovation in every Caldera system, allowing intermittent renewable energy to be converted to on-demand heat. Multiple heat cells are installed to meet the site’s requirements, and this array can sit outside. The suite of patented and patent-pending technologies needed to make a heat cell took years to develop, yet the principles behind it are surprisingly simple.
Solid Core
Each heat cell contains a solid core, made from Caldera’s proprietary composite of recycled aluminium and volcanic rocks. This ‘supermaterial’ has a high energy density and is conductive, durable, and affordable. Recycled aluminium comes from sources such as used car engine blocks and incinerator waste, creating a demand for this low-grade metal. Molten aluminium is poured over volcanic rock to create a solid core, and this process can be reversed should product reach the end of its useful life.
Heat cell cores are heated from electricity using straight-forward electric elements. Thanks to the high conductivity the heat spreads throughout the block. Cores are considered ‘full’ when they reach 500°C. They are ‘empty’ when this temperature drops back down to around 200°C (depending on the application).
Vacuum Insulation
Each core is encased in a double-walled vessel, effectively a vacuum flask. The vacuum itself prevents conduction and convection of heat, while an additional material prevents radiative losses. Caldera’s proprietary vacuum system delivering lasting performance over years without maintenance, though the vacuum can be ‘topped up’ during servicing should this become necessary.
Unlike with conventional insulation, there is no need to create a larger cell to limit surface area. This means that each heat cell can be small enough to enable mass production, and easy transport to site. This is one of the many ways in which the Caldera System is design to allow scaling and cost efficiencies.
Heat Extraction
A small quantity of water is passed through the heat cell array and flashed to steam to extract energy. Even when the system is being used to supply steam, the Caldera System has separate loop to maintain ultra-high purity and avoid degradation over the years from the build-up of solids.
Using steam for heat extraction has significant advantages over the most common alternative fluid, which is hot air. Energy density is several times higher, leading to smaller pipe sizes and significant cost and space savings. It also leads to high performance, in that energy can be extracted quickly.
