Abstract: A process of control of a thermal energy storage unit in the ground includes heat exchangers buried in the ground, each of the exchangers allowing a calorific energy exchange between a heat-conveying fluid traversing it and the ground, the energy storage unit being at the interface between a source and consumer of calorific energy to store thermal energy. One measures the temperature in various points of the ground using buried temperature gauges, the temperatures and flow of a heat-conveying fluid in input and output of the source to determine the thermal power provided by the source, and temperatures and flow of a heat-conveying fluid in input and output of the consumer to determine the thermal power to provide the consumer. One optimizes the storage of thermal energy in the storage unit by selecting active exchangers among the plurality of exchangers according to temperature measurements, flow measurements and thermal power measurements.