Testimonio II, Principality of Monaco (2019)

An innovative large-scale project founded on a complex energy foundation

This new building in the heart of Monaco includes two, 25-storey residential towers with 348 flats, 1’100 parking spaces, a 50-crib day nursery and a new site for the 700 students of the International School of Monaco. For this project, GEOEG performed the schematic design, thermal performance tests, and the detailed design of a complex energy foundation supporting such construction. The foundation comprised 165 energy piles and approximately 5’800 m² of energy barrettes. The system will meet 100% of the thermal energy consumption of the considered building as a part of a broader system accounting for different technologies that harvest renewable energy sources.

Following the schematic design of such energy foundation project, GEOEG performed the world-first thermal performance tests of 70-m long energy barrettes – structural support elements for tall buildings. The considered tests allowed a measurement of the extractable thermal power from the considered energy geostructures and a characterization of the thermo-physical properties of the ground. Thermal performance tests were specifically performed on energy barrettes equipped with different pipe configurations to determine the optimal solution in terms of energy performance, ease of installation, and economic tradeoff.

Based on a thorough experimental characterization of the underground, the detailed design was performed via 3D time-dependent thermo-hydraulic finite element simulations of both energy barrette and energy pile groups. Such analyses allowed a thorough quantification of the thermal interactions among the considered geothermal heat exchangers, an assessment of the impact of such interactions on the energy yield of the foundation, and a long-term evaluation of the performance and profitability of the considered system. The simulations accounted for the actual pipe configuration embedded in the modeled energy geostructures, the circulation of a heat carrier fluid in such pipes, the surface thermal conditions, the dynamic building operation, and the ON/OFF operation of the ground source heat pump system.