A concept of thermal energy storage system for solar heat storage from summer to winter using absorption process is presented. The application aimed would be the coverage of all the heating needs of a residential building equipped of solar collectors for domestic hot water production and space heating. The different phases of the corresponding absorption cycle as well as the components involved are described, and an example of static dimensioning is given for the components for the case of the LiBr/H2O couple. The covering of all the heating needs of a 120 m2 house in the alpine region of France would need mainly two tanks of respectively about 20 m3 of LiBr/H2O solution. However, this is only a first evaluation and dynamic simulations are needed to refine this value. Keywords