The effectiveness of thermal energy storage is ALWAYS dependant the volume and speed of energy transfer between the stored energy (bank), and its recipient.
EnergiVault does not have a physical heat exchanger, with the energy store in line with an exisiting or conventional cooling curcuit, the heat exchange between two ice particles and the working fluid takes place in the storage vessel, what we refer to as an Organic Heat Exchanger.
The Organic Heat Exchanger is key to EnergiVault’s integration success.
Thermal exchange occurs through a “heat exchanger” and usually takes the form of :
Tube in tube - Where contra-flowing fluids exchange their thermal energy through the wall of concentric pipes, usually in a coiled form.
Shell and Tube - Where thermal exchange is accomplished through a bundle of enclosed tubes.
Plate - Where dissimilar fluids occupy both sides of a matrix of plates.
Tube - in - tube heat exchanger |

Plate Heat exchanger
|
 Shell and Tube heat exchanger |
Conventional heat exchangers are all limited by their physical size as this depicts how much heat exchange surface is available to the dissimilar temperature fluids, passing either side of the heat exchange surface. For compactness, the plate heat exchanger is the obvious choice, but often NOT when one or both fluids carry particulate contamination, thus with the potential for blockage.
The tube in tube heat exchanger, although significantly larger in size, also can present difficulties in cleaning, should fowling occur.
Shell and tube heat exchanger, although smaller in size than its tube-in-tube counterpart, still has limitations.
In ALL cases, the heat-transfer capability is limited by the available heat transfer surface.
The Organic Heat Exchanger eliminates ALL issues with heat transfer processes because the heat transfer surface increases proportionately with the volume of energy in storage.
The Organic Heat Exchanger is so named because it uses the slight film of organic material surrounding each stored energy-rich particle as the only barrier to heat transfer.
The more particles stored, the higher the heat transfer surface available.
By example, an EnergiVault battery with a full charge capacity of 1MWh thermal, could support a cooling load of 6MW for 10 minutes duration.
Similarly, the same EnergiVault could discharge at 100KW for a duration of 10 hours.
This level of flexibility is unavailable from any other heat exchanger type.