Ice storage is nothing else than a storage where the medium undergoes a phase change. Due to the high energy density release/absorbed during the phase change from water to/from ice, this type of storage will have a higher capacity than a normal hot water storage, for the same volume. This will be reflected in setting the maximum capacity of the ice storage to a consequently higher value than for a standard hot water storage.

In our case, we will give the energy carrier the name anergy (even though indeed, it is a medium fluctuating between hot water and ice). The system represented here considers the use of solar thermal collectors for direct heating use as well as to charge the ice storage. A heat pump is part of the system and has the two following modes: heat pump on ice storage or on air.

The efficiency on the ice storage mode must be selected carefully. It is assumed that the cold month will have a lower COP (due to the temperature of the storage), while on the other hand, in summer, the heat pump will not be used, as the solar will already have the expected temperature. In this case, the efficiency of the summer months must be lower than the direct conversion from solar to hot water, for the system to avoid this mode.

 

Set-up summary

Energy Carriers

Energy Demands

Imports

 

Supply technology

 

 

Storage technology

Solar thermal

Heat pump 1

Heat pump 2

Virtual technology

Solar converter

Virtual technology

Anergy converter

Ice storage (Generic Hot Water Storage)

Electricity

 

X

 

Primary Input

Primary Input

 

 

X

Solar roof

 

X

(primary) Input

 

 

 

 

 

Ambient heat

 

X

 

 

Input

 

 

 

Heat 30-40°C

X

 

 

(primary) Output

(primary) output

(primary) output

 

 

Heat 70-80°C

 

 

(primary) Output

 

 

(primary) input

 

 

Anergy

 

 

 

Input

 

 

 

 

 

Set-up Implementation

A virtual technology must be created to allow for solar thermal heat (here name heat 70-80°C) to be directly use, during summer.

Another virtual technology must be created to allow the solar heat (here named heat 70-80°C) to be turned into ‘anergy’ (a reminder that the naming here is not always correct as the stored medium is fluctuating between hot water and ice).  and as such, stored within the storage.

Ice storage have a higher capacity than a normal hot water storage, for the same volume. This can be reflected by setting a maximum capacity of the ice storage to a consequently higher value than for a standard hot water storage.

The efficiency on the ice storage mode must be selected carefully. It is assumed that the cold month will have a lower COP (due to the temperature of the storage), while on the other hand, in summer, the heat pump will not be used, as the solar will already have the expected temperature. In this case, the efficiency of the summer months must be lower than the direct conversion from solar to hot water, for the system to avoid this mode.