Heat storage device

A device for storing heat energy/cold energy, comprising:

• a container comprising a first end wall comprising a first interface suitable for letting a fluid into the device, a second end wall comprising a second interface suitable for letting the fluid out of the device, and a side wall connecting the first end wall and the second end wall along a main longitudinal direction of the container,
• a plurality of storage elements arranged in the container and configured to store heat energy/cold energy supplied by the fluid,
• wherein the container has at least one perforated internal wall comprising openings of dimensions smaller than the dimensions of the storage elements and defining a first compartment and a second compartment in the container, the plurality of storage elements being distributed in the first compartment and in the second compartment,
• wherein each of the first compartment and the second compartment has a respective drainage orifice in the side wall.