A device including first and second heat accumulators, each including thermal energy storage containers. Each container includes an insulating enclosure containing earth crossed by at least one first line for the circulation of a first heat transfer fluid and at least one second line for the circulation of a second heat transfer fluid. For each accumulator, the first lines of the containers are connected in parallel and the second lines of the containers are series-connected. The heating device includes a device for delivering thermal energy to the first heat transfer fluid connected to the first and second accumulators by a first circuit for distributing the first heat transfer fluid capable of selectively circulating the first heat transfer fluid in the first line of each container of the first accumulator or in the first line of each container of the second accumulator.

A system comprising a main circuit for routing a flow of heat transfer liquid out of a thermal storage to at least one outer heat exchanger and back to the thermal storage again, a main circulation pump configured to force the heat transfer liquid through the main circuit, a temperature sensor configured to measure the temperature of the heat transfer liquid, and a controller configured to control the main circulation pump based on temperature readings of the temperature sensor such that a calculated Reynolds number for the flow of heat transfer liquid is constant at a predetermined target Reynolds number over at least a primary temperature range.