Thermal energy storage inside a rocky massif

The Solargeotherm research project, coordinated by the French bureau of geologic and mining research (BRGM), aims at identifying the possible uses of a rocky massif as a low temperature heat reservoir. The experiment is actually in progress in a quarry of Pyrennes-Orientales (SW France). Heat is collected with a 41 m2 solar field made of 21 solar thermal panels and transferred to the underground (160 to 180 m depth) with 3 geothermal drills. The study of the rocky massif has shown that an homogeneous geological context is one of the conditions of success for the project. In France, about 40% of the territory would fit with this technology (no environmental impact on aquifers). The cost of the project is 1 million euros. It lies within the framework of the Stock-E research program of the national research agency (ANR). (J.S.)